获取地理位置信息
概述
HTML5 的 Geolocation API 为 Web 应用提供了获取设备地理位置信息的能力，是构建基于位置服务（LBS）的核心技术之一。该 API 允许网页在用户明确授权的情况下，通过多种定位方式（GPS、Wi-Fi、基站、IP 地址等）获取设备的精确位置。
<h4>001-geolocation.html</h4>html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>【1】地理位置获取</title>
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; padding: 20px; background: #f8f9fa; color: #333; }
.demo-container { max-width: 700px; margin: 0 auto; background: white; padding: 24px; border-radius: 8px; box-shadow: 0 2px 8px rgba(0,0,0,0.1); }
.demo-title { margin-bottom: 16px; font-size: 18px; color: #555; border-bottom: 2px solid #007bff; padding-bottom: 8px; }
.location-card {
background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
color: white;
border-radius: 16px;
padding: 28px;
text-align: center;
margin-bottom: 24px;
position: relative;
overflow: hidden;
}
.location-card::before {
content: '';
position: absolute;
top: -50%; right: -30%;
width: 300px; height: 300px;
background: rgba(255,255,255,0.1);
border-radius: 50%;
}
.location-icon { font-size: 48px; margin-bottom: 12px; position: relative; z-index: 1; }
.status-text { font-size: 16px; opacity: 0.9; position: relative; z-index: 1; }
.btn {
display: inline-flex; align-items: center; gap: 8px;
padding: 14px 32px; border: none; border-radius: 10px;
cursor: pointer; font-size: 15px; font-weight: 600;
transition: all 0.3s; margin-bottom: 24px;
}
.btn-primary {
background: linear-gradient(135deg, #007bff, #0056b3);
color: white; box-shadow: 0 4px 14px rgba(0,123,255,0.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(0,123,255,0.45); }
.btn-primary:disabled { background: #ccc; cursor: not-allowed; transform: none; box-shadow: none; }
.info-grid {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
gap: 14px; margin-top: 20px;
}
.info-item {
background: #f8f9fa; border-radius: 10px;
padding: 16px; border: 1px solid #e9ecef;
transition: transform 0.2s;
}
.info-item:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.06); }
.info-label { font-size: 12px; color: #888; margin-bottom: 6px; text-transform: uppercase; letter-spacing: 0.5px; }
.info-value { font-size: 17px; font-weight: 600; color: #333; font-family: monospace; word-break: break-all; }
.error-panel {
background: #fff5f5; border-left: 4px solid #fc8181;
padding: 16px; border-radius: 6px; margin-top: 20px; display: none;
}
.error-panel h4 { color: #c53030; margin-bottom: 8px; }
.error-panel p { color: #742a2a; font-size: 14px; line-height: 1.6; }
.options-bar {
display: flex; gap: 16px; align-items: center; flex-wrap: wrap;
margin-bottom: 16px; padding: 14px; background: #f8f9fa; border-radius: 8px;
}
.options-bar label { font-size: 13px; font-weight: 500; color: #555; }
.toggle-switch {
width: 44px; height: 24px; background: #ccc; border-radius: 12px;
position: relative; cursor: pointer; transition: background 0.3s;
}
.toggle-switch.active { background: #007bff; }
.toggle-switch::after {
content: ''; position: absolute; width: 18px; height: 18px;
background: white; border-radius: 50%; top: 3px; left: 3px;
transition: left 0.3s;
}
.toggle-switch.active::after { left: 23px; }
</style>
</head>
<body>
<div class="demo-container">
<div class="demo-title">示例：HTML5 Geolocation API - 获取地理位置</div>
<div class="location-card" id="locationCard">
<div class="location-icon" id="locIcon">📍</div>
<div class="status-text" id="statusText">点击下方按钮获取您的位置</div>
</div>
<div style="text-align: center;">
<button class="btn btn-primary" id="getLocationBtn" onclick="requestLocation()">
🌍 获取我的位置
</button>
</div>
<div class="options-bar">
<label for="highAccuracyToggle">高精度模式 (GPS)</label>
<div class="toggle-switch" id="highAccuracyToggle" onclick="this.classList.toggle('active')"></div>
</div>
<div class="info-grid" id="infoGrid"></div>
<div class="error-panel" id="errorPanel">
<h4>⚠️ 获取位置失败</h4>
<p id="errorMessage"></p>
</div>
</div>
<script>
const locationCard = document.getElementById("locationCard")
const locIcon = document.getElementById("locIcon")
const statusText = document.getElementById("statusText")
const infoGrid = document.getElementById("infoGrid")
const errorPanel = document.getElementById("errorPanel")
const errorMessage = document.getElementById("errorMessage")
const getLocationBtn = document.getElementById("getLocationBtn")
function requestLocation() {
// 重置状态
errorPanel.style.display = "none"
infoGrid.innerHTML = ""
locIcon.textContent = "⏳"
statusText.textContent = "正在请求位置权限..."
getLocationBtn.disabled = true
// 检测支持
if (!navigator.geolocation) {
showError("您的浏览器不支持 Geolocation API", null)
return
}
const highAccuracy = document.getElementById("highAccuracyToggle").classList.contains("active")
navigator.geolocation.getCurrentPosition(
(position) => showLocation(position),
(error) => handleError(error),
{
enableHighAccuracy: highAccuracy,
timeout: 15000,
maximumAge: 0
}
)
}
function showLocation(position) {
const coords = position.coords
const timestamp = new Date(position.timestamp)
locIcon.textContent = "✅"
statusText.textContent = `成功获取位置 · ${timestamp.toLocaleTimeString()}`
const data = [
{ label: "纬度 Latitude", value: coords.latitude.toFixed(7) + "°" },
{ label: "经度 Longitude", value: coords.longitude.toFixed(7) + "°" },
{ label: "精度 Accuracy", value: Math.round(coords.accuracy) + " 米" },
{ label: "海拔 Altitude", value: coords.altitude !== null ? coords.altitude.toFixed(1) + " 米" : "不可用" },
{ label: "海拔精度", value: coords.altitudeAccuracy !== null ? coords.altitudeAccuracy.toFixed(1) + " 米" : "不可用" },
{ label: "方向 Heading", value: coords.heading !== null ? coords.heading.toFixed(1) + "°" : "不可用" },
{ label: "速度 Speed", value: coords.speed !== null ? coords.speed.toFixed(2) + " m/s" : "不可用" },
{ label: "时间戳", value: timestamp.toLocaleString() }
]
infoGrid.innerHTML = data.map(item => `
<div class="info-item">
<div class="info-label">${item.label}</div>
<div class="info-value">${item.value}</div>
</div>
`).join("")
getLocationBtn.disabled = false
}
function handleError(error) {
let msg = ""
switch (error.code) {
case error.PERMISSION_DENIED:
msg = "用户拒绝了位置请求。请在浏览器设置中允许访问位置信息，然后重试。<br><br>💡 提示：Chrome 地址栏左侧点击锁/信息图标 → 位置 → 允许"
break
case error.POSITION_UNAVAILABLE:
msg = "无法获取位置信息。可能的原因：<br>• GPS 信号弱（室内常见）<br>• 网络连接问题<br>• 设备无定位硬件"
break
case error.TIMEOUT:
msg = "获取位置超时。请检查网络连接或尝试在户外使用高精度模式。"
break
default:
msg = `未知错误：${error.message || "发生未知错误"}`
}
showError(msg, error.code)
}
function showError(msg, code) {
errorMessage.innerHTML = msg
errorPanel.style.display = "block"
locIcon.textContent = "❌"
statusText.textContent = code ? `错误代码: ${code}` : "获取失败"
getLocationBtn.disabled = false
}
</script>
</body>
</html>```
<h4>002-geolocation-basic.html</h4>
```html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>【2】Geolocation API 基础用法</title>
<!--
来源: HTML5基础知识/16-获取地理位置信息.md
知识点: getCurrentPosition 一次性获取 + 配置项 enableHighAccuracy/timeout/maximumAge
-->
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
padding: 20px; background: linear-gradient(135deg, #0c1445, #1a237e);
color: #e0e0e0; min-height: 100vh;
}
.container { max-width: 900px; margin: 0 auto; }
.header {
text-align: center; padding: 24px; background: linear-gradient(135deg, #2196f3, #00bcd4);
color: white; border-radius: 12px; margin-bottom: 24px;
}
.header h1 { font-size: 22px; margin-bottom: 6px; }
.header p { opacity: 0.9; font-size: 14px; }
.card {
background: rgba(255,255,255,0.06); border: 1px solid rgba(255,255,255,0.12);
border-radius: 12px; padding: 24px; margin-bottom: 20px; backdrop-filter: blur(10px);
}
.card-title {
font-size: 15px; font-weight: 600; color: #64b5f6;
border-left: 3px solid #2196f3; padding-left: 10px; margin-bottom: 16px;
}
.info-banner {
background: rgba(33,150,243,0.15); border: 1px solid rgba(33,150,243,0.3);
border-radius: 8px; padding: 14px 18px; font-size: 13px; line-height: 1.7;
color: #90caf9; margin-bottom: 20px;
}
/* 配置面板 */
.config-grid {
display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
gap: 14px; margin-bottom: 20px;
}
.config-item {
background: rgba(0,0,0,0.25); border: 1px solid rgba(255,255,255,0.08);
border-radius: 8px; padding: 14px;
}
.config-label { font-size: 11px; color: #888; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 6px; }
.config-control { display: flex; align-items: center; gap: 8px; }
.toggle-switch {
width: 44px; height: 24px; background: #37474f; border-radius: 12px;
position: relative; cursor: pointer; transition: background 0.3s;
}
.toggle-switch.active { background: #2196f3; }
.toggle-switch::after {
content: ''; position: absolute; width: 18px; height: 18px;
background: white; border-radius: 50%; top: 3px; left: 3px;
transition: transform 0.3s;
}
.toggle-switch.active::after { transform: translateX(20px); }
.config-value { font-size: 13px; color: #b0bec5; }
input[type="number"] {
width: 70px; padding: 6px 8px; background: rgba(0,0,0,0.4); border: 1px solid #455a64;
color: #fff; border-radius: 4px; font-size: 13px;
}
input:focus { outline: none; border-color: #2196f3; }
.btn {
padding: 12px 28px; border: none; border-radius: 8px; cursor: pointer;
font-size: 14px; font-weight: 600; transition: all 0.25s;
}
.btn-primary {
background: linear-gradient(135deg, #2196f3, #00bcd4); color: white;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(33,150,243,0.35); }
.btn-primary:disabled { opacity: 0.4; cursor: not-allowed; transform: none !important; }
/* 结果展示 */
.result-panel {
background: rgba(0,0,0,0.3); border-radius: 10px; overflow: hidden;
}
.result-header {
display: flex; justify-content: space-between; align-items: center;
padding: 12px 18px; background: rgba(255,255,255,0.05); font-size: 13px;
font-weight: 600; color: #90caf9;
}
.coords-display {
padding: 20px; text-align: center;
}
.coord-value {
font-family: 'SF Mono', Monaco, monospace; font-size: 22px; font-weight: 700;
color: #4fc3f7;
}
.coord-label { font-size: 12px; color: #666; margin-top: 4px; }
.data-grid {
display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px;
background: rgba(255,255,255,0.05);
}
.data-cell {
padding: 12px 16px; background: rgba(0,0,0,0.2);
display: flex; justify-content: space-between; align-items: center;
}
.data-key { font-size: 12px; color: #888; }
.data-val { font-size: 13px; font-weight: 600; color: #e0e0e0; font-family: monospace; }
/* 状态 */
.status-bar {
display: flex; align-items: center; gap: 10px; padding: 14px 18px;
background: rgba(0,0,0,0.2); border-radius: 8px; margin-top: 16px;
font-size: 13px;
}
.status-dot {
width: 10px; height: 10px; border-radius: 50%;
}
.status-dot.idle { background: #607d8b; }
.status-dot.loading { background: #ffc107; animation: pulse 1s infinite; }
.status-dot.success { background: #4caf50; box-shadow: 0 0 8px rgba(76,175,80,0.5); }
.status-dot.error { background: #f44336; }
@keyframes pulse { 0%,100%{opacity:1}50%{opacity:.4} }
.compat-note {
background: rgba(255,152,0,0.1); border: 1px solid rgba(255,152,0,0.25);
border-radius: 6px; padding: 10px 14px; font-size: 12px; color: #ffcc80;
margin-top: 16px;
}
</style>
</head>
<body>
<div class="container">
<div class="header">
<h1>📍 Geolocation API 基础用法</h1>
<p>getCurrentPosition 一次性获取位置 + 完整配置选项演示</p>
</div>
<div class="card">
<div class="card-title">🎛️ 定位配置与执行</div>
<div class="info-banner">
💡 <strong>navigator.geolocation.getCurrentPosition()</strong> 是获取用户当前位置的核心 API。<br>
• <strong>enableHighAccuracy:</strong> 使用 GPS 高精度模式（更耗电但更准确）<br>
• <strong>timeout:</strong> 等待定位的最长时间（毫秒），超时触发错误回调<br>
• <strong>maximumAge:</strong> 可接受的缓存位置最大年龄（ms），0 表示不要缓存
</div>
<!-- 配置选项 -->
<div class="config-grid">
<div class="config-item">
<div class="config-label">高精度模式 (enableHighAccuracy)</div>
<div class="config-control">
<div class="toggle-switch" id="toggleAccuracy" onclick="this.classList.toggle('active')"></div>
<span class="config-value" id="labelAccuracy">关闭 (省电模式)</span>
</div>
</div>
<div class="config-item">
<div class="config-label">超时时间 (timeout) 毫秒</div>
<div class="config-control">
<input type="number" id="inputTimeout" value="10000" min="1000" step="1000" />
<span class="config-value" style="font-size:11px;">默认 10s</span>
</div>
</div>
<div class="config-item">
<div class="config-label">缓存有效期 (maximumAge) 毫秒</div>
<div class="config-control">
<input type="number" id="inputMaxAge" value="0" min="0" step="1000" />
<span class="config-value" style="font-size:11px;">0 = 不使用缓存</span>
</div>
</div>
</div>
<div style="text-align:center;">
<button class="btn btn-primary" id="locateBtn" onclick="requestLocation()">📍 获取我的位置</button>
</div>
<!-- 结果展示 -->
<div class="result-panel" style="margin-top: 20px;" id="resultPanel">
<div class="result-header">
<span>🌍 定位结果</span>
<span id="timestamp">-</span>
</div>
<div class="coords-display">
<div style="display:inline-block;margin:0 30px;text-align:center;">
<div class="coord-value" id="valLat">--</div>
<div class="coord-label">纬度 Latitude</div>
</div>
<div style="display:inline-block;margin:0 30px;text-align:center;">
<div class="coord-value" id="valLng">--</div>
<div class="coord-label">经度 Longitude</div>
</div>
</div>
<div class="data-grid" id="dataGrid">
<div class="data-cell"><span class="data-key">精度 accuracy</span><span class="data-val" id="valAcc">-</span></div>
<div class="data-cell"><span class="data-key">海拔 altitude</span><span class="data-val" id="valAlt">-</span></div>
<div class="data-cell"><span class="data-key">海拔精度 altAccuracy</span><span class="data-val" id="valAltAcc">-</span></div>
<div class="data-cell"><span class="data-key">方向 heading</span><span class="data-val" id="valHead">-</span></div>
<div class="data-cell"><span class="data-key">速度 speed</span><span class="data-val" id="valSpeed">-</span></div>
<div class="data-cell"><span class="data-key">配置 enableHighAccuracy</span><span class="data-val" id="valConfig">-</span></div>
</div>
</div>
<!-- 状态栏 -->
<div class="status-bar">
<span class="status-dot idle" id="statusDot"></span>
<span id="statusText">就绪 — 点击按钮开始定位（浏览器会弹出权限请求）</span>
</div>
<div class="compat-note">
⚠️ <strong>兼容性与安全要求：</strong>
Chrome 50+ 要求 HTTPS 环境（localhost 除外）。
首次调用会弹出系统级权限请求对话框，用户必须明确授权才能获取位置。
在不支持 Geolocation 的环境中会自动降级提示。
</div>
</div>
</div>
<script>
// ====== UI 更新函数 ======
function setStatus(text, type) {
const dot = document.getElementById('statusDot');
const label = document.getElementById('statusText');
dot.className = `status-dot ${type}`;
label.textContent = text;
}
// 监听高精度开关
document.getElementById('toggleAccuracy').addEventListener('click', function() {
const isActive = this.classList.contains('active');
document.getElementById('labelAccuracy').textContent = isActive ? '开启 (GPS模式)' : '关闭 (省电模式)';
});
// ====== 核心定位功能 ======
function requestLocation() {
// 兼容性检测
if (!navigator.geolocation) {
setStatus('❌ 您的浏览器不支持 Geolocation API', 'error');
alert('您的浏览器不支持地理位置功能');
return;
}
const btn = document.getElementById('locateBtn');
btn.disabled = true;
// 读取配置
const options = {
enableHighAccuracy: document.getElementById('toggleAccuracy').classList.contains('active'),
timeout: parseInt(document.getElementById('inputTimeout').value) || 10000,
maximumAge: parseInt(document.getElementById('inputMaxAge').value) || 0
};
setStatus(`⏳ 正在请求位置... (高精度:${options.enableHighAccuracy} | 超时:${options.timeout}ms | 缓存:${options.maximumAge}ms)`, 'loading');
const startTime = performance.now();
navigator.geolocation.getCurrentPosition(
// 成功回调
function(position) {
const elapsed = ((performance.now() - startTime) / 1000).toFixed(2);
// 更新坐标
document.getElementById('valLat').textContent = position.coords.latitude.toFixed(7);
document.getElementById('valLng').textContent = position.coords.longitude.toFixed(7);
document.getElementById('timestamp').textContent = new Date().toLocaleString();
// 更新详细数据
document.getElementById('valAcc').textContent = position.coords.accuracy.toFixed(1) + ' m';
document.getElementById('valAlt').textContent = position.coords.altitude !== null
? position.coords.altitude.toFixed(1) + ' m' : '不可用';
document.getElementById('valAltAcc').textContent = position.coords.altitudeAccuracy !== null
? position.coords.altitudeAccuracy.toFixed(1) + ' m' : '不可用';
document.getElementById('valHead').textContent = position.coords.heading !== null
? position.coords.heading.toFixed(1) + '°' : '不可用';
document.getElementById('valSpeed').textContent = position.coords.speed !== null
? position.coords.speed.toFixed(2) + ' m/s' : '不可用';
document.getElementById('valConfig').textContent = options.enableHighAccuracy ? '开启' : '关闭';
setStatus(`✅ 定位成功! 耗时 ${elapsed}s`, 'success');
btn.disabled = false;
console.log('完整 Position 对象:', position);
console.log('完整 Coordinates 对象:', position.coords);
},
// 错误回调
function(error) {
let msg = '';
switch (error.code) {
case error.PERMISSION_DENIED:
msg = '用户拒绝了位置请求权限';
break;
case error.POSITION_UNAVAILABLE:
msg = '无法获取位置信息（GPS/Wi-Fi不可用）';
break;
case error.TIMEOUT:
msg = `定位超时 (${options.timeout}ms 内未完成)`;
break;
default:
msg = '未知错误: ' + error.message;
}
setStatus(`❌ ${msg}`, 'error');
btn.disabled = false;
console.error('Geolocation Error:', error);
},
// 配置选项
options
);
}
</script>
</body>
</html>html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>【4】地理位置错误处理详解</title>
<!--
来源: HTML5基础知识/16-获取地理位置信息.md
知识点: PERMISSION_DENIED / POSITION_UNAVAILABLE / TIMEOUT 三种错误的友好提示
-->
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
padding: 20px; background: #1a1a2e; color: #e0e0e0;
min-height: 100vh;
}
.container { max-width: 920px; margin: 0 auto; }
.header {
text-align: center; padding: 24px; background: linear-gradient(135deg, #fc4a1a, #f7b733);
color: white; border-radius: 12px; margin-bottom: 24px;
}
.header h1 { font-size: 22px; margin-bottom: 6px; }
.header p { opacity: 0.9; font-size: 14px; }
.card {
background: #16213e; border: 1px solid #0f3460; border-radius: 10px;
padding: 24px; margin-bottom: 20px;
}
.card-title {
font-size: 15px; font-weight: 600; color: #f39c12;
border-left: 3px solid #e74c3c; padding-left: 10px; margin-bottom: 16px;
}
/* 错误类型卡片 */
.error-types { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-bottom: 24px; }
@media (max-width: 700px) { .error-types { grid-template-columns: 1fr; } }
.error-card {
border-radius: 10px; overflow: hidden; border: 2px solid transparent;
transition: all 0.3s;
}
.error-card.active { border-color: currentColor; transform: scale(1.02); box-shadow: 0 8px 32px rgba(0,0,0,0.2); }
.error-card.permission { --ecolor: #e74c3c; }
.error-card.unavailable { --ecolor: #f39c12; }
.error-card.timeout { --ecolor: #3498db; }
.err-header {
padding: 14px 16px; font-weight: 700; font-size: 14px; color: var(--ecolor);
text-align: center; background: rgba(255,255,255,0.03);
}
.err-body { padding: 16px; }
.err-code {
font-family: monospace; font-size: 12px; background: rgba(0,0,0,0.3);
padding: 4px 10px; border-radius: 4px; display: inline-block;
color: var(--ecolor); margin-bottom: 8px;
}
.err-desc { font-size: 12px; color: #aaa; line-height: 1.6; margin-bottom: 10px; }
.err-solution {
font-size: 11px; padding: 8px 12px; border-radius: 6px;
background: rgba(255,255,255,0.04); line-height: 1.5;
}
.err-solution strong { color: var(--ecolor); }
/* 触发按钮 */
.trigger-btns { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; margin-bottom: 24px; }
.btn {
padding: 10px 22px; border: none; border-radius: 6px; cursor: pointer;
font-size: 13px; font-weight: 600; transition: all 0.2s;
}
.btn-perm { background: #e74c3c; color: white; }
.btn-perm:hover { background: #c0392b; }
.btn-unavail { background: #f39c12; color: #1a1a2e; }
.btn-unavail:hover { background: #e67e22; }
.btn-timeout { background: #3498db; color: white; }
.btn-timeout:hover { background: #2980b9; }
.btn-normal { background: #27ae60; color: white; }
.btn-normal:hover { background: #2ecc71; }
/* 模拟结果展示 */
.result-stage {
background: #0a0a1a; border-radius: 10px; padding: 24px;
min-height: 200px; display: flex; flex-direction: column;
align-items: center; justify-content: center;
border: 2px dashed #333; transition: all 0.3s;
}
.result-stage.success { border-color: #27ae60; border-style: solid; }
.result-stage.error { border-style: solid; }
.result-icon { font-size: 48px; margin-bottom: 12px; }
.result-title { font-size: 18px; font-weight: 700; margin-bottom: 6px; }
.result-desc { font-size: 13px; color: #888; text-align: center; max-width: 400px; line-height: 1.6; }
.result-detail {
margin-top: 16px; background: rgba(0,0,0,0.3); border-radius: 6px;
padding: 12px 16px; font-family: monospace; font-size: 11px;
width: 100%; max-width: 500px; color: #aaa;
}
.detail-row { display: flex; justify-content: space-between; padding: 3px 0; border-bottom: 1px solid #222; }
/* PositionError 属性表 */
.prop-table { width: 100%; border-collapse: collapse; font-size: 12px; margin-top: 16px; }
.prop-table th, .prop-table td {
padding: 8px 12px; text-align: left; border-bottom: 1px solid #222;
}
.prop-table th { background: rgba(255,255,255,0.03); color: #888; }
.compat-note {
background: rgba(52,152,219,0.1); border: 1px solid rgba(52,152,219,0.25);
border-radius: 6px; padding: 10px 14px; font-size: 12px; color: #85c1e9;
margin-top: 16px;
}
</style>
</head>
<body>
<div class="container">
<div class="header">
<h1>⚠️ 地理位置 错误处理详解</h1>
<p>PERMISSION_DENIED / POSITION_UNAVAILABLE / TIMEOUT — 三种错误类型及友好提示</p>
</div>
<div class="card">
<div class="card-title">🔍 三种错误类型</div>
<div class="error-types">
<div class="error-card permission" id="cardPerm">
<div class="err-header">🚫 PERMISSION_DENIED (1)</div>
<div class="err-body">
<div class="err-code">error.PERMISSION_DENIED → 1</div>
<div class="err-desc">用户拒绝了地理定位请求，或页面没有获得定位权限。</div>
<div class="err-solution">
<strong>💡 解决方案：</strong><br>
• 引导用户到设置中开启位置权限<br>
• 提供手动输入地址的备选方案<br>
• 解释为什么需要位置信息以增加授权率
</div>
</div>
</div>
<div class="error-card unavailable" id="cardUnavail">
<div class="err-header">📡 POSITION_UNAVAILABLE (2)</div>
<div class="err-body">
<div class="err-code">error.POSITION_UNAVAILABLE → 2</div>
<div class="err-desc">无法获取位置信息。网络断开、GPS 信号弱、或定位服务被禁用。</div>
<div class="err-solution">
<strong>💡 解决方案：</strong><br>
• 检查网络连接状态<br>
• 提示用户检查设备的定位服务开关<br>
• 尝试使用 IP 定位作为降级方案
</div>
</div>
</div>
<div class="error-card timeout" id="cardTimeout">
<div class="err-header">⏱️ TIMEOUT (3)</div>
<div class="err-body">
<div class="err-code">error.TIMEOUT → 3</div>
<div class="err-desc">在指定的 timeout 时间内未能获取到位置信息。</div>
<div class="err-solution">
<strong>💡 解决方案：</strong><br>
• 增加 timeout 值（室内可能需要更长）<br>
• 降低 enableHighAccuracy 以加快响应<br>
• 设置合理的 maximumAge 使用缓存
</div>
</div>
</div>
</div>
<!-- 触发测试 -->
<div class="trigger-btns">
<button class="btn btn-normal" onclick="testLocation()">✅ 正常获取位置</button>
<button class="btn btn-perm" onclick="simulateError('permission')">🚫 模拟拒绝权限</button>
<button class="btn btn-unavail" onclick="simulateError('unavailable')">📡 模拟不可用</button>
<button class="btn btn-timeout" onclick="simulateError('timeout')">⏱️ 模拟超时</button>
</div>
<!-- 结果展示 -->
<div class="result-stage" id="resultStage">
<div class="result-icon">📍</div>
<div class="result-title">等待测试</div>
<div class="result-desc">点击上方按钮模拟不同的定位结果和错误场景</div>
</div>
<!-- PositionError 属性表 -->
<table class="prop-table">
<thead>
<tr><th>属性</th><th>类型</th><th>说明</th></tr>
</thead>
<tbody>
<tr><td><code>code</code></td><td>Number</td><td>错误代码：1=PERMISSION_DENIED, 2=UNAVAILABLE, 3=TIMEOUT</td></tr>
<tr><td><code>message</code></td><td>String</td><td>人类可读的错误描述信息</td></tr>
</tbody>
</table>
<div class="compat-note">
ℹ️ 注意：实际运行时，<strong>PERMISSION_DENIED</strong> 需要用户在系统弹窗中主动选择"拒绝"；
<strong>TIMEOUT</strong> 可通过设置极短的 timeout 值来触发；<strong>POSITION_UNAVAILABLE</strong>
在正常环境下较难复现（通常需要断网或禁用定位服务）。
</div>
</div>
</div>
<script>
const stage = document.getElementById('resultStage');
function showResult(type, title, desc, detail) {
stage.className = 'result-stage ' + (type === 'success' ? 'success' : 'error');
const icons = { success: '✅', permission: '🚫', unavailable: '📡', timeout: '⏱️' };
const colors = { success: '#27ae60', permission: '#e74c3c', unavailable: '#f39c12', timeout: '#3498db' };
stage.innerHTML = `
<div class="result-icon">${icons[type]}</div>
<div class="result-title" style="color:${colors[type]}">${title}</div>
<div class="result-desc">${desc}</div>
${detail ? `<div class="result-detail">${detail}</div>` : ''}
`;
}
// 清除所有卡片激活状态
function clearActive() {
document.querySelectorAll('.error-card').forEach(c => c.classList.remove('active'));
}
// 正常获取
function testLocation() {
clearActive();
showResult('', '正在请求...', '请允许位置权限...', '');
if (!navigator.geolocation) {
showResult('unavailable', 'API 不支持', '当前浏览器不支持 Geolocation API', '');
return;
}
navigator.geolocation.getCurrentPosition(
function(pos) {
showResult('success', '✅ 定位成功',
`纬度: ${pos.coords.latitude.toFixed(6)}<br/>经度: ${pos.coords.longitude.toFixed(6)}<br/>精度: ±${pos.coords.accuracy.toFixed(1)}m`,
`<div class="detail-row"><span>code</span><span>- (无错误)</span></div>
<div class="detail-row"><span>latitude</span><span>${pos.coords.latitude.toFixed(7)}</span></div>
<div class="detail-row"><span>longitude</span><span>${pos.coords.longitude.toFixed(7)}</span></div>
<div class="detail-row"><span>accuracy</span><span>${pos.coords.accuracy.toFixed(1)} m</span></div>`
);
},
function(err) {
handleRealError(err);
},
{ enableHighAccuracy: true, timeout: 15000, maximumAge: 0 }
);
}
// 处理真实错误
function handleRealError(err) {
const types = { 1: 'permission', 2: 'unavailable', 3: 'timeout' };
const titles = { 1: '🚫 权限被拒绝', 2: '📡 位置不可用', 3: '⏱️ 获取超时' };
const descs = {
1: '用户拒绝了位置访问权限请求。<br/>请在浏览器设置中允许位置访问后重试。',
2: '无法获取位置信息。<br/>可能原因：定位服务关闭、网络问题、或设备无定位能力。',
3: '在规定时间内未能完成定位。<br/>可尝试增大 timeout 或降低精度要求。'
};
const t = types[err.code];
clearActive();
const card = document.getElementById(t === 'permission' ? 'cardPerm' : t === 'unavailable' ? 'cardUnavail' : 'cardTimeout');
if (card) card.classList.add('active');
showResult(t, titles[err.code], descs[err.code],
`<div class="detail-row"><span>code</span><span>${err.code} (${['','PERMISSION_DENIED','POSITION_UNAVAILABLE','TIMEOUT'][err.code]})</span></div>
<div class="detail-row"><span>message</span><span>"${err.message}"</span></div>`
);
}
// 模拟错误
function simulateError(type) {
clearActive();
const cardMap = { permission: 'cardPerm', unavailable: 'cardUnavail', timeout: 'cardTimeout' };
const card = document.getElementById(cardMap[type]);
if (card) card.classList.add('active');
const fakeErrors = {
permission: { code: 1, message: 'User denied Geolocation access.' },
unavailable: { code: 2, message: 'Network location provider at \'https://\' : User denied Geolocation.' },
timeout: { code: 3, message: 'Timeout expired' }
};
const err = fakeErrors[type];
if (type === 'timeout') {
// TIMEOUT 可以真实触发
showResult(type, '⏱️ 获取超时', '尝试用极短的超时时间触发...',
`<div class="detail-row"><span>设置的 timeout</span><span>1 ms</span></div>`);
navigator.geolocation.getCurrentPosition(
() => {},
(e) => handleRealError(e),
{ timeout: 1, maximumAge: 0 }
);
} else {
// 直接展示模拟结果
const titles = { permission: '🚫 权限被拒绝 (模拟)', unavailable: '📡 位置不可用 (模拟)' };
const descs = {
permission: '这是模拟的 PERMISSION_DENIED 错误。<br/>实际场景：用户在系统弹窗中点击了"不允许"。',
unavailable: '这是模拟的 POSITION_UNAVAILABLE 错误。<br/>实际场景：定位服务关闭或网络不可达。'
};
showResult(type, titles[type], descs[type],
`<div class="detail-row"><span>code</span><span>${err.code}</span></div>
<div class="detail-row"><span>message</span><span>"${err.message}"</span></div>`
);
}
}
</script>
</body>
</html>核心特性
- 用户隐私保护：必须经过用户明确授权才能获取位置信息
- 多种定位方式：自动选择最优定位方式（GPS > Wi-Fi > 基站 > IP）
- 实时位置追踪：支持持续监听位置变化
- 精度可控：可通过配置项平衡精度和性能
- 跨平台支持：桌面端和移动端浏览器均支持
应用场景
| 应用类型 | 典型场景 | 定位需求 |
|---|---|---|
| 地图导航 | 路线规划、实时导航 | 高精度、实时更新 |
| 生活服务 | 附近餐厅、打车服务 | 中等精度 |
| 社交应用 | 附近的人、位置打卡 | 中等精度 |
| 天气服务 | 本地天气预报 | 低精度即可 |
| 电商物流 | 配送地址定位 | 中等精度 |
| 运动健身 | 轨迹记录、配速统计 | 高精度、实时更新 |
工作原理
plaintext
┌─────────────┐
│ 浏览器请求 │
└──────┬──────┘
│
▼
┌─────────────────┐
│ 用户授权提示框 │
└──────┬──────────┘
│
┌───┴───┐
│ 授权? │
└───┬───┘
│
┌───┴────────────────────────┐
│ │
▼ ▼
允许 拒绝
│ │
▼ ▼
┌──────────────────┐ ┌─────────────┐
│ 选择定位方式: │ │ 返回错误: │
│ • GPS (最精确) │ │ PERMISSION_ │
│ • Wi-Fi (中等) │ │ DENIED │
│ • 基站 (较低) │ └─────────────┘
│ • IP (最低) │
└────────┬─────────┘
│
▼
┌──────────────────┐
│ 返回 Position │
│ 对象包含: │
│ • 经纬度 │
│ • 精度 │
│ • 海拔 (可选) │
│ • 速度 (可选) │
└──────────────────┘定位技术分类
不同的定位技术在精度、覆盖范围和功耗上各有优劣。浏览器会根据设备能力和环境自动选择最优的定位方式：
图表渲染中…
浏览器兼容性
桌面浏览器支持
| 浏览器 | 支持版本 | 备注 |
|---|---|---|
| Chrome | 5+ | 完整支持，50+ 版本要求 HTTPS |
| Firefox | 3.5+ | 完整支持 |
| Safari | 5+ | 完整支持 |
| Edge | 12+ | 完整支持 |
| Internet Explorer | 9+ | 基本支持，部分功能受限 |
| Opera | 10.6+ | 完整支持 |
移动浏览器支持
| 浏览器 | 支持版本 | 备注 |
|---|---|---|
| iOS Safari | 3.2+ | 完整支持 |
| Android Browser | 2.1+ | 完整支持 |
| Chrome for Android | 18+ | 完整支持 |
| Firefox for Android | 4+ | 完整支持 |
| UC Browser | 11+ | 基本支持 |
| 微信浏览器 | 全版本 | 完整支持 |
特性支持情况
| 特性 | Chrome | Firefox | Safari | Edge | 备注 |
|---|---|---|---|---|---|
getCurrentPosition | ✅ | ✅ | ✅ | ✅ | 核心功能 |
watchPosition | ✅ | ✅ | ✅ | ✅ | 核心功能 |
clearWatch | ✅ | ✅ | ✅ | ✅ | 核心功能 |
| HTTPS 要求 | 50+ | 55+ | ✅ | ✅ | 安全限制 |
| Permissions API | ✅ | ✅ | ❌ | ✅ | 权限查询 |
兼容性检测代码
javascript
// 检测 Geolocation API 支持情况
function checkGeolocationSupport() {
const support = {
basic: "geolocation" in navigator,
permissions: "permissions" in navigator,
https: location.protocol === "https:" || location.hostname === "localhost"
}
console.log("Geolocation 支持情况:")
console.log("- 基础 API:", support.basic ? "✅ 支持" : "❌ 不支持")
console.log("- Permissions API:", support.permissions ? "✅ 支持" : "❌ 不支持")
console.log("- HTTPS 环境:", support.https ? "✅ 是" : "⚠️ 否 (部分浏览器可能受限)")
return support
}
// 使用示例
checkGeolocationSupport()检查浏览器是否支持
javascript
if ("geolocation" in navigator) {
// 浏览器支持地理定位
console.log("浏览器支持地理定位")
} else {
// 浏览器不支持地理定位
console.warn("您的浏览器不支持地理定位功能")
alert("您的浏览器不支持地理定位功能")
}API 详解
<h4>003-watchposition-tracking.html</h4>html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>【3】watchPosition 持续追踪位置变化</title>
<!--
来源: HTML5基础知识/16-获取地理位置信息.md
知识点: watchPosition 持续追踪、实时更新坐标、速度/方向信息
-->
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
padding: 20px; background: #0d1117; color: #c9d1d9;
min-height: 100vh;
}
.container { max-width: 1000px; margin: 0 auto; }
.header {
text-align: center; padding: 24px; background: linear-gradient(135deg, #238636, #2ea043);
color: white; border-radius: 12px; margin-bottom: 24px;
}
.header h1 { font-size: 22px; margin-bottom: 6px; }
.header p { opacity: 0.9; font-size: 14px; }
.card {
background: #161b22; border: 1px solid #30363d; border-radius: 10px;
padding: 24px; margin-bottom: 20px;
}
.card-title {
font-size: 15px; font-weight: 600; color: #3fb950;
border-left: 3px solid #3fb950; padding-left: 10px; margin-bottom: 16px;
}
.info-banner {
background: rgba(46,204,113,0.08); border: 1px solid rgba(46,204,113,0.2);
border-radius: 6px; padding: 12px 16px; font-size: 13px; line-height: 1.6;
color: #7ee787; margin-bottom: 16px;
}
/* 控制区 */
.controls { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-bottom: 20px; }
.btn {
padding: 10px 22px; border: none; border-radius: 6px; cursor: pointer;
font-size: 13px; font-weight: 600; transition: all 0.2s;
}
.btn-green { background: #238636; color: white; }
.btn-green:hover { background: #2ea043; }
.btn-red { background: #da3633; color: white; }
.btn-red:hover { background: #f85149; }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }
/* 实时数据仪表盘 */
.dashboard { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 12px; margin-bottom: 20px; }
.gauge {
background: #0d1117; border: 1px solid #21262d; border-radius: 8px;
padding: 16px; text-align: center;
}
.gauge-icon { font-size: 24px; margin-bottom: 6px; }
.gauge-value {
font-size: 20px; font-weight: 700; font-family: 'SF Mono', monospace;
color: #58a6ff;
}
.gauge-label { font-size: 11px; color: #6e7681; margin-top: 4px; }
/* 地图区域 (Canvas) */
.map-area {
background: #0d1117; border: 1px solid #30363d; border-radius: 10px;
overflow: hidden; position: relative;
}
.map-canvas { display: block; width: 100%; }
.map-overlay {
position: absolute; top: 10px; right: 10px;
background: rgba(0,0,0,0.75); backdrop-filter: blur(8px);
border-radius: 6px; padding: 8px 12px; font-size: 11px; color: #8b949e;
}
/* 轨迹日志 */
.track-log {
background: #0d1117; border-radius: 6px; padding: 14px;
font-family: monospace; font-size: 11px; max-height: 200px;
overflow-y: auto; color: #6e7681; line-height: 1.7;
}
.log-entry { padding: 2px 0; border-bottom: 1px solid #161b22; }
.log-entry.pos { color: #3fb950; }
.log-entry.speed { color: #58a6ff; }
.log-entry.warn { color: #d29922; }
.log-entry.err { color: #f85149; }
/* 统计 */
.stats-row {
display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px;
margin-top: 16px;
}
.stat-box {
background: #0d1117; border: 1px solid #21262d; border-radius: 6px;
padding: 12px; text-align: center;
}
.stat-val { font-size: 17px; font-weight: 700; color: #c9d1d9; }
.stat-lbl { font-size: 10px; color: #6e7681; margin-top: 2px; }
.compat-note {
background: rgba(210,153,34,0.1); border: 1px solid rgba(210,153,34,0.25);
border-radius: 6px; padding: 10px 14px; font-size: 12px; color: #d29922;
margin-top: 16px;
}
</style>
</head>
<body>
<div class="container">
<div class="header">
<h1>🛰️ watchPosition 持续追踪</h1>
<p>实时监控位置变化 — 坐标 / 速度 / 方向 / 海拔 动态更新</p>
</div>
<div class="card">
<div class="card-title">📍 追踪控制台</div>
<div class="info-banner">
💡 <strong>watchPosition()</strong> 与 <code>getCurrentPosition()</code> 不同，它会持续监听设备位置变化，
每当位置发生改变时调用回调。适合导航、运动轨迹记录等场景。<br>
📌 返回一个 watch ID，可通过 <code>clearWatch(watchId)</code> 停止追踪。
</div>
<div class="controls">
<button class="btn btn-green" id="startBtn" onclick="startWatching()">▶ 开始追踪</button>
<button class="btn btn-red" id="stopBtn" onclick="stopWatching()" disabled>⛹ 停止追踪</button>
<label style="font-size:13px;color:#8b949e;">高精度:</label>
<select id="accuracyMode" style="padding:6px 10px;background:#0d1117;border:1px solid #30363d;color:#c9d1d9;border-radius:4px;font-size:12px;">
<option value="false">普通精度 (省电)</option>
<option value="true">高精度 (GPS)</option>
</select>
</div>
<!-- 实时仪表盘 -->
<div class="dashboard">
<div class="gauge">
<div class="gauge-icon">🌐</div>
<div class="gauge-value" id="gLat">--</div>
<div class="gauge-label">纬度</div>
</div>
<div class="gauge">
<div class="gauge-icon">🧭</div>
<div class="gauge-value" id="gLng">--</div>
<div class="gauge-label">经度</div>
</div>
<div class="gauge">
<div class="gauge-icon">🚀</div>
<div class="gauge-value" id="gSpeed">--</div>
<div class="gauge-label">速度 (m/s)</div>
</div>
<div class="gauge">
<div class="gauge-icon">➡️</div>
<div class="gauge-value" id="gHeading">--</div>
<div class="gauge-label">方向 (°)</div>
</div>
<div class="gauge">
<div class="gauge-icon">📏</div>
<div class="gauge-value" id="gAlt">--</div>
<div class="gauge-label">海拔 (m)</div>
</div>
<div class="gauge">
<div class="gauge-icon">🎯</div>
<div class="gauge-value" id="gAcc">--</div>
<div class="gauge-label">精度 (m)</div>
</div>
</div>
<!-- Canvas 地图 -->
<div class="map-area">
<canvas id="mapCanvas" class="map-canvas" width="940" height="350"></canvas>
<div class="map-overlay" id="mapOverlay">点击 "开始追踪" 启动</div>
</div>
<!-- 统计 -->
<div class="stats-row">
<div class="stat-box"><div class="stat-val" id="statUpdates">0</div><div class="stat-lbl">更新次数</div></div>
<div class="stat-box"><div class="stat-val" id="statDuration">0s</div><div class="stat-lbl">追踪时长</div></div>
<div class="stat-box"><div class="stat-val" id="statMaxSpeed">-</div><div class="stat-lbl">最高速度</div></div>
<div class="stat-box"><div class="stat-val" id="statAvgAcc">-</div><div class="stat-lbl">平均精度</div></div>
</div>
<!-- 日志 -->
<div class="track-log" id="trackLog">
<div class="log-entry warn">[系统] watchPosition 追踪就绪。点击 "开始追踪" 后请移动设备以观察位置变化。</div>
</div>
<div class="compat-note">
⚠️ <strong>注意：</strong>watchPosition 在桌面浏览器中通常不会频繁触发（因为桌面设备位置基本不变）。
在移动设备上或使用开发者工具模拟 GPS 时效果最佳。
</div>
</div>
</div>
<script>
const canvas = document.getElementById('mapCanvas');
const ctx = canvas.getContext('2d');
const logEl = document.getElementById('trackLog');
let watchId = null;
let trackPoints = [];
let updateCount = 0;
let startTime = null;
let timerInterval = null;
let maxSpeed = 0;
let accSum = 0;
function log(msg, type = '') {
const div = document.createElement('div');
div.className = `log-entry ${type}`;
div.textContent = `[${new Date().toTimeString().substring(0,8)}] ${msg}`;
logEl.appendChild(div);
logEl.scrollTop = logEl.scrollHeight;
}
// ====== Canvas 绘制 ======
function resizeCanvas() {
const rect = canvas.parentElement.getBoundingClientRect();
canvas.width = rect.width;
canvas.height = 350;
drawMap();
}
window.addEventListener('resize', resizeCanvas);
resizeCanvas();
function drawMap() {
ctx.fillStyle = '#0d1117';
ctx.fillRect(0, 0, canvas.width, canvas.height);
// 网格
ctx.strokeStyle = '#21262d';
ctx.lineWidth = 1;
for (let x = 0; x < canvas.width; x += 40) {
ctx.beginPath(); ctx.moveTo(x, 0); ctx.lineTo(x, canvas.height); ctx.stroke();
}
for (let y = 0; y < canvas.height; y += 40) {
ctx.beginPath(); ctx.moveTo(0, y); ctx.lineTo(canvas.width, y); ctx.stroke();
}
if (trackPoints.length === 0) return;
// 归一化坐标到画布
const lats = trackPoints.map(p => p.lat);
const lngs = trackPoints.map(p => p.lng);
const minLat = Math.min(...lats), maxLat = Math.max(...lats);
const minLng = Math.min(...lngs), maxLng = Math.max(...lngs);
const pad = 40;
function toX(lng) {
if (maxLng === minLng) return canvas.width / 2;
return pad + ((lng - minLng) / (maxLng - minLng)) * (canvas.width - 2*pad);
}
function toY(lat) {
if (maxLat === minLat) return canvas.height / 2;
return pad + ((lat - minLat) / (maxLat - minLat)) * (canvas.height - 2*pad);
}
// 绘制轨迹线
if (trackPoints.length > 1) {
ctx.beginPath();
ctx.strokeStyle = '#238636';
ctx.lineWidth = 2;
ctx.moveTo(toX(trackPoints[0].lng), toY(trackPoints[0].lat));
for (let i = 1; i < trackPoints.length; i++) {
ctx.lineTo(toX(trackPoints[i].lng), toY(trackPoints[i].lat));
}
ctx.stroke();
}
// 绘制点
trackPoints.forEach((p, i) => {
const isLast = i === trackPoints.length - 1;
ctx.beginPath();
ctx.arc(toX(p.lng), toY(p.lat), isLast ? 8 : 4, 0, Math.PI * 2);
ctx.fillStyle = isLast ? '#58a6ff' : '#3fb950';
ctx.fill();
if (isLast) {
ctx.strokeStyle = '#58a6ff'; ctx.lineWidth = 2; ctx.stroke();
}
});
// 当前位置标注
if (trackPoints.length > 0) {
const last = trackPoints[trackPoints.length - 1];
const x = toX(last.lng), y = toY(last.lat);
ctx.fillStyle = '#58a6ff';
ctx.font = 'bold 11px system-ui';
ctx.fillText(`${last.lat.toFixed(5)}, ${last.lng.toFixed(5)}`, x + 14, y - 4);
}
}
// ====== 追踪控制 ======
function startWatching() {
if (!navigator.geolocation) {
log('❌ 浏览器不支持 Geolocation', 'err'); return;
}
const highAcc = document.getElementById('accuracyMode').value === 'true';
document.getElementById('startBtn').disabled = true;
document.getElementById('stopBtn').disabled = false;
trackPoints = [];
updateCount = 0;
maxSpeed = 0;
accSum = 0;
startTime = performance.now();
// 计时器
timerInterval = setInterval(() => {
const s = ((performance.now() - startTime) / 1000).toFixed(0);
document.getElementById('statDuration').textContent = s + 's';
}, 1000);
log(`▶ 开始追踪 (高精度: ${highAcc})`, 'warn');
document.getElementById('mapOverlay').textContent = '追踪中...';
watchId = navigator.geolocation.watchPosition(
function(position) {
updateCount++;
const c = position.coords;
// 更新仪表盘
document.getElementById('gLat').textContent = c.latitude.toFixed(7);
document.getElementById('gLng').textContent = c.longitude.toFixed(7);
document.getElementById('gSpeed').textContent = c.speed !== null ? c.speed.toFixed(2) : '--';
document.getElementById('gHeading').textContent = c.heading !== null ? c.heading.toFixed(1) : '--';
document.getElementById('gAlt').textContent = c.altitude !== null ? c.altitude.toFixed(1) : '--';
document.getElementById('gAcc').textContent = c.accuracy.toFixed(1);
// 更新统计
document.getElementById('statUpdates').textContent = updateCount;
if (c.speed !== null && c.speed > maxSpeed) {
maxSpeed = c.speed;
document.getElementById('statMaxSpeed').textContent = maxSpeed.toFixed(2) + ' m/s';
}
accSum += c.accuracy;
document.getElementById('statAvgAcc').textContent = (accSum / updateCount).toFixed(1) + ' m';
// 记录轨迹点
trackPoints.push({ lat: c.latitude, lng: c.longitude, time: Date.now() });
drawMap();
log(`#${updateCount} lat=${c.latitude.toFixed(6)} lng=${c.longitude.toFixed(6)} acc=${c.accuracy}m${c.speed ? ' spd='+c.speed.toFixed(1)+'m/s' : ''}`,
c.speed ? 'speed' : 'pos');
},
function(err) {
const msgs = { 1:'PERMISSION_DENIED', 2:'POSITION_UNAVAILABLE', 3:'TIMEOUT' };
log(`❌ 错误: ${msgs[err.code] || err.message}`, 'err');
},
{
enableHighAccuracy: highAcc,
timeout: 30000,
maximumAge: 0
}
);
}
function stopWatching() {
if (watchId !== null) {
navigator.geolocation.clearWatch(watchId);
watchId = null;
}
if (timerInterval) { clearInterval(timerInterval); timerInterval = null; }
document.getElementById('startBtn').disabled = false;
document.getElementById('stopBtn').disabled = true;
document.getElementById('mapOverlay').textContent = `已停止 (共 ${updateCount} 次更新)`;
log(`⛹ 追踪已停止。共收到 ${updateCount} 次位置更新。`, 'warn');
}
</script>
</body>
</html>获取当前位置 getCurrentPosition
getCurrentPosition 方法用于获取设备的当前位置信息。
语法：
javascript
navigator.geolocation.getCurrentPosition(successCallback, errorCallback, options)参数说明：
successCallback：成功获取位置时的回调函数，接收一个Position对象作为参数errorCallback：获取位置失败时的回调函数（可选），接收一个PositionError对象作为参数options：配置选项对象（可选）
基本示例：
javascript
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(
(position) => {
const coords = position.coords
console.log("纬度:", coords.latitude)
console.log("经度:", coords.longitude)
console.log("精度:", coords.accuracy, "米")
},
(error) => {
console.error("获取位置失败:", error.message)
}
)
} else {
console.error("浏览器不支持地理定位")
}使用 Promise 封装：
javascript
function getCurrentPosition(options = {}) {
return new Promise((resolve, reject) => {
if (!navigator.geolocation) {
reject(new Error("浏览器不支持地理定位"))
return
}
navigator.geolocation.getCurrentPosition(resolve, reject, options)
})
}
// 使用示例
try {
const position = await getCurrentPosition({
enableHighAccuracy: true,
timeout: 10000,
maximumAge: 0
})
console.log("位置信息:", position.coords)
} catch (error) {
console.error("获取位置失败:", error)
}持续监听位置 watchPosition
如果需要持续监听位置变化（例如导航应用），可以使用 watchPosition 方法。该方法会持续监听设备位置，并在位置发生变化时触发回调函数。
语法：
javascript
const watchId = navigator.geolocation.watchPosition(successCallback, errorCallback, options)参数说明：
successCallback：位置更新时的回调函数errorCallback：错误回调函数（可选）options：配置选项对象（可选）- 返回值：返回一个数字 ID，用于停止监听
停止监听：
javascript
navigator.geolocation.clearWatch(watchId)完整示例：
javascript
let watchId = null
// 开始监听位置变化
function startWatching() {
if (!navigator.geolocation) {
console.error("浏览器不支持地理定位")
return
}
watchId = navigator.geolocation.watchPosition(
(position) => {
const coords = position.coords
console.log("当前位置更新:")
console.log("纬度:", coords.latitude)
console.log("经度:", coords.longitude)
console.log("速度:", coords.speed, "米/秒")
console.log("方向:", coords.heading, "度")
// 更新地图标记或执行其他操作
updateMapMarker(coords.latitude, coords.longitude)
},
(error) => {
console.error("监听位置失败:", error.message)
},
{
enableHighAccuracy: true,
timeout: 5000,
maximumAge: 0
}
)
}
// 停止监听
function stopWatching() {
if (watchId !== null) {
navigator.geolocation.clearWatch(watchId)
watchId = null
console.log("已停止监听位置")
}
}
// 使用示例
startWatching()
// 5秒后停止监听
setTimeout(() => {
stopWatching()
}, 5000)注意事项：
watchPosition会持续消耗设备电量，使用完毕后务必调用clearWatch停止监听- 建议在应用进入后台或用户离开页面时停止监听
- 移动设备上使用
watchPosition时，建议设置合理的maximumAge以减少电量消耗
数据对象
Geolocation API 涉及三个核心数据对象：Position、Coordinates 和 PositionError。理解这些对象的结构和属性对于正确使用 API 至关重要。
Position 对象
如果获取地理位置信息成功，则可以在获取成功的回调函数中通过访问 position 对象的属性来得到这些地理位置信息。position 对象包含两个属性：coords 和 timestamp。
属性说明
coords：只读属性，返回一个表示当前位置的Coordinates对象timestamp：只读属性，返回一个时间戳（DOMTimeStamp），表示获取地理位置时的时间，通常为 UTC 时间 1970 年 1 月 1 日午夜以来的总毫秒数
Coordinates 对象
Coordinates 对象表示设备在地球上的位置、海拔，以及计算这些属性的精度等信息。
| 属性 | 类型 | 说明 | 可能值 |
|---|---|---|---|
latitude | number | 当前地理位置的纬度（度） | -90 到 90 |
longitude | number | 当前地理位置的经度（度） | -180 到 180 |
accuracy | number | 获取到的纬度或经度的精度（以米为单位） | 正数 |
altitude | number | null | 当前地理位置的海拔高度（米） | 数字或 null |
altitudeAccuracy | number | null | 获取到的海拔高度的精度（以米为单位） | 数字或 null |
heading | number | null | 设备的前进方向（度），0-360，正北为 0 | 数字或 null |
speed | number | null | 设备的前进速度（米/秒） | 数字或 null |
完整示例：
javascript
function successCallback(position) {
const coords = position.coords
const timestamp = position.timestamp
console.log("=== 位置信息 ===")
console.log("纬度:", coords.latitude)
console.log("经度:", coords.longitude)
console.log("精度:", coords.accuracy, "米")
console.log("海拔:", coords.altitude !== null ? coords.altitude + " 米" : "不可用")
console.log("海拔精度:", coords.altitudeAccuracy !== null ? coords.altitudeAccuracy + " 米" : "不可用")
console.log("方向:", coords.heading !== null ? coords.heading + " 度" : "不可用")
console.log("速度:", coords.speed !== null ? coords.speed + " 米/秒" : "不可用")
console.log("时间戳:", new Date(timestamp).toLocaleString())
}html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>显示当前的详细位置信息</title>
<script type="text/javascript">
function body_onLoad() {
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(geo_onSuccess, geo_onError) //获取地理位置信息
} else {
geo_onError() //处理错误
}
}
function geo_onSuccess(pos) {
document.getElementById("accuracySpan").innerHTML = pos.coords.accuracy
document.getElementById("altitudeSpan").innerHTML = pos.coords.altitude ?? "不可用"
document.getElementById("altitudeAccuracySpan").innerHTML = pos.coords.altitudeAccuracy ?? "不可用"
document.getElementById("headingSpan").innerHTML = pos.coords.heading ?? "不可用"
document.getElementById("latitudeSpan").innerHTML = pos.coords.latitude
document.getElementById("longitudeSpan").innerHTML = pos.coords.longitude
document.getElementById("speedSpan").innerHTML = pos.coords.speed ?? "不可用"
}
function geo_onError() {
alert("您当前使用的浏览器不支持Geolocation")
}
</script>
<style>
li {
float: left; /* 浮云在左侧 */
min-width: 49%; /* 设置最小宽度 */
min-height: 30px; /* 设置最小高度 */
border-bottom: solid 1px grey; /* 设置下边框 */
}
</style>
</head>
<body onLoad="body_onLoad();">
<h2>当前地理位置信息</h2>
<ul style="list-style: none">
<li>经纬度的精度(accuracy):</li>
<li><span id="accuracySpan"></span></li>
<li>海拔高度(altitude):</li>
<li><span id="altitudeSpan"></span></li>
<li>海拔高度的精度(altitudeAccuracy):</li>
<li><span id="altitudeAccuracySpan"></span></li>
<li>航向(heading):</li>
<li><span id="headingSpan"></span></li>
<li>纬度(latitude):</li>
<li><span id="latitudeSpan"></span></li>
<li>经度(longitude):</li>
<li><span id="longitudeSpan"></span></li>
<li>前进速度(speed):</li>
<li><span id="speedSpan"></span></li>
</ul>
</body>
</html>PositionError 对象
当获取地理位置信息失败时，错误回调函数会接收一个 PositionError 对象作为参数。
PositionError 属性：
code：错误代码（数字），表示错误类型message：错误信息（字符串），用于开发和调试，不适合直接展示给用户
错误代码说明：
| code 属性值 | 常量名 | 说明 | 常见原因 |
|---|---|---|---|
| 1 | PERMISSION_DENIED | 用户拒绝了获取位置信息的请求 | 用户点击"拒绝"按钮，或在浏览器设置中禁用了定位 |
| 2 | POSITION_UNAVAILABLE | 网络不可用或者无法连接到获取位置信息的卫星 | GPS信号弱、网络故障、设备无定位硬件 |
| 3 | TIMEOUT | 网络可用但是在计算用户的位置上花了太长时间 | 网络延迟、GPS搜索时间长、timeout设置过短 |
| 4 | UNKNOWN_ERROR | 发生其他未知错误 | 未知原因，极少发生 |
错误处理
良好的错误处理机制是确保应用稳定性的关键。Geolocation API 的错误处理需要考虑多种场景。
基本错误处理示例
javascript
function errorCallback(error) {
let errorMessage = "无法获取位置信息: "
switch (error.code) {
case error.PERMISSION_DENIED:
errorMessage += "用户拒绝了地理定位请求"
break
case error.POSITION_UNAVAILABLE:
errorMessage += "位置信息不可用"
break
case error.TIMEOUT:
errorMessage += "获取用户位置超时"
break
case error.UNKNOWN_ERROR:
errorMessage += "发生未知错误"
break
default:
errorMessage += "未知错误"
}
console.error(errorMessage)
console.error("错误详情:", error.message)
// 显示用户友好的错误提示
alert(errorMessage)
}
// 使用示例
navigator.geolocation.getCurrentPosition(
(position) => {
console.log("位置信息:", position.coords)
},
errorCallback,
{
timeout: 5000
}
)配置选项
getCurrentPosition 和 watchPosition 方法的第三个参数是一个配置对象，用于指定获取位置信息的行为。
选项说明
| 属性 | 类型 | 默认值 | 说明 |
|---|---|---|---|
enableHighAccuracy | boolean | false | 是否启用高精度模式。设为 true 时，设备会使用更精确的定位方式（如 GPS），但会消耗更多电量和时间 |
timeout | number | Infinity | 超时时间（毫秒）。如果在该时间内未获取到地理位置信息，则返回 TIMEOUT 错误 |
maximumAge | number | 0 | 可接受的缓存位置的最大年龄（毫秒）。设为 0 表示不使用缓存，必须获取新位置；设为 Infinity 表示可以使用任意旧的缓存位置 |
配置示例
javascript
// 基本配置
const basicOptions = {
enableHighAccuracy: false,
timeout: 5000,
maximumAge: 0
}
// 高精度配置（适用于需要精确定位的场景）
const highAccuracyOptions = {
enableHighAccuracy: true,
timeout: 10000,
maximumAge: 0
}
// 使用缓存的配置（适用于对实时性要求不高的场景）
const cacheOptions = {
enableHighAccuracy: false,
timeout: 5000,
maximumAge: 60000 // 使用1分钟内的缓存位置
}
// 实际使用
navigator.geolocation.getCurrentPosition(
(position) => {
console.log("位置信息:", position.coords)
},
(error) => {
console.error("错误:", error)
},
highAccuracyOptions
)配置建议
- 一般场景：使用默认配置或设置较短的
timeout - 导航应用：启用
enableHighAccuracy: true，设置合理的timeout - 节省电量：设置较大的
maximumAge值，使用缓存位置 - 实时追踪：设置
maximumAge: 0，确保获取最新位置
实际应用案例
案例 1：显示详细位置信息
html
<!DOCTYPE html>
<html>
<head>
<title>地理位置示例</title>
<style>
#map {
height: 600px;
width: 100%;
}
#location-info {
padding: 10px;
background: #f5f5f5;
border-bottom: 1px solid #ddd;
font-family: Arial, sans-serif;
}
</style>
</head>
<body>
<div id="location-info"></div>
<div id="map"></div>
<script src="https://api.map.baidu.com/api?v=3.0&ak=nNMEzPeiw73A2BnUfsPG373YuTrvN60p"></script>
<script>
// 坐标转换函数
function convertCoordinate(lng, lat, callback) {
const convertor = new BMap.Convertor()
const pointArr = [new BMap.Point(lng, lat)]
convertor.translate(pointArr, 1, 5, (data) => {
if (data.status === 0) {
callback(data.points[0])
}
})
}
// 获取当前位置
function initMap(position) {
const lat = position.coords.latitude
const lng = position.coords.longitude
// 显示原始坐标
const locationInfo = document.getElementById("location-info")
locationInfo.innerHTML = `
<p>原始坐标(WGS84): 经度 ${lng.toFixed(6)}, 纬度 ${lat.toFixed(6)}</p>
`
// 创建地图实例
const map = new BMap.Map("map")
// 将WGS84坐标转换为百度坐标
convertCoordinate(lng, lat, (point) => {
// 显示转换后坐标
locationInfo.innerHTML += `
<p>百度坐标(BD09): 经度 ${point.lng.toFixed(6)}, 纬度 ${point.lat.toFixed(6)}</p>
`
// 初始化地图，设置中心点坐标和地图级别
map.centerAndZoom(point, 15)
// 启用滚轮缩放
map.enableScrollWheelZoom()
// 创建标记
const marker = new BMap.Marker(point)
// 将标记添加到地图中
map.addOverlay(marker)
// 设置标记标题
marker.setTitle("您的位置")
})
}
function showError(error) {
switch (error.code) {
case error.PERMISSION_DENIED:
alert("请允许访问您的位置以查看地图")
break
case error.POSITION_UNAVAILABLE:
alert("无法获取您的位置信息")
break
case error.TIMEOUT:
alert("获取位置超时")
break
default:
alert("发生未知错误")
}
}
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(initMap, showError, {
enableHighAccuracy: true,
timeout: 10000
})
} else {
alert("您的浏览器不支持地理定位")
}
</script>
</body>
</html>案例 2：反向地理编码（经纬度转地址）
使用第三方地图服务将经纬度转换为具体的地址信息。
html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>反向地理编码示例</title>
<style>
#location {
padding: 20px;
background: #f5f5f5;
border-radius: 8px;
margin: 20px;
font-family: Arial, sans-serif;
}
.loading {
color: #666;
font-style: italic;
}
.address {
font-size: 18px;
color: #333;
margin-top: 10px;
}
.coords {
font-size: 14px;
color: #999;
margin-top: 5px;
}
.error {
color: #d32f2f;
padding: 20px;
background: #ffebee;
border-radius: 8px;
margin: 20px;
}
</style>
</head>
<body>
<div id="location" class="loading">正在获取位置信息...</div>
<script>
// 使用百度地图 API 进行反向地理编码
async function reverseGeocode(lat, lng) {
const BMap = window.BMap
const geocoder = new BMap.Geocoder()
return new Promise((resolve, reject) => {
const point = new BMap.Point(lng, lat)
geocoder.getLocation(point, (result) => {
if (result) {
resolve({
address: result.address,
province: result.addressComponents.province,
city: result.addressComponents.city,
district: result.addressComponents.district,
street: result.addressComponents.street,
streetNumber: result.addressComponents.streetNumber
})
} else {
reject(new Error('无法获取地址信息'))
}
})
})
}
// 获取位置并转换地址
async function getLocationAndAddress() {
const locationEl = document.getElementById('location')
try {
// 检查浏览器支持
if (!navigator.geolocation) {
throw new Error('浏览器不支持地理定位')
}
// 获取当前位置
const position = await new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject, {
enableHighAccuracy: true,
timeout: 10000,
maximumAge: 0
})
})
const lat = position.coords.latitude
const lng = position.coords.longitude
// 进行反向地理编码
const addressInfo = await reverseGeocode(lat, lng)
// 显示结果
locationEl.className = 'location'
locationEl.innerHTML = `
<div class="address">📍 当前地址：${addressInfo.address}</div>
<div class="coords">
详细信息：${addressInfo.province} ${addressInfo.city} ${addressInfo.district}<br>
街道：${addressInfo.street} ${addressInfo.streetNumber}<br>
坐标：${lng.toFixed(6)}, ${lat.toFixed(6)}<br>
精度：${position.coords.accuracy.toFixed(0)} 米
</div>
`
} catch (error) {
locationEl.className = 'error'
let errorMessage = '获取位置失败：'
if (error.code === error.PERMISSION_DENIED) {
errorMessage += '用户拒绝了位置请求'
} else if (error.code === error.POSITION_UNAVAILABLE) {
errorMessage += '位置信息不可用'
} else if (error.code === error.TIMEOUT) {
errorMessage += '请求超时'
} else {
errorMessage += error.message
}
locationEl.textContent = errorMessage
}
}
// 加载百度地图 API
function loadBaiduMapAPI() {
return new Promise((resolve) => {
if (window.BMap) {
resolve()
return
}
window.initBaiduMap = resolve
const script = document.createElement('script')
script.src = 'https://api.map.baidu.com/api?v=3.0&ak=YOUR_API_KEY&callback=initBaiduMap'
document.head.appendChild(script)
})
}
// 初始化
async function init() {
try {
await loadBaiduMapAPI()
await getLocationAndAddress()
} catch (error) {
const locationEl = document.getElementById('location')
locationEl.className = 'error'
locationEl.textContent = '初始化失败：' + error.message
}
}
// 页面加载完成后执行
window.addEventListener('load', init)
</script>
</body>
</html>高德地图版本：
javascript
// 使用高德地图进行反向地理编码
async function reverseGeocodeAMap(lat, lng) {
return new Promise((resolve, reject) => {
if (typeof AMap === 'undefined') {
reject(new Error('高德地图 API 未加载'))
return
}
AMap.plugin('AMap.Geocoder', () => {
const geocoder = new AMap.Geocoder({
radius: 1000, // 搜索半径
extensions: 'all'
})
geocoder.getAddress([lng, lat], (status, result) => {
if (status === 'complete' && result.regeocode) {
const addressComponent = result.regeocode.addressComponent
resolve({
formattedAddress: result.regeocode.formattedAddress,
province: addressComponent.province,
city: addressComponent.city || addressComponent.province,
district: addressComponent.district,
township: addressComponent.township,
street: addressComponent.streetNumber.street,
streetNumber: addressComponent.streetNumber.number
})
} else {
reject(new Error('无法获取地址信息'))
}
})
})
})
}
// 使用示例
async function showAddress() {
try {
const position = await new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject)
})
const addressInfo = await reverseGeocodeAMap(
position.coords.latitude,
position.coords.longitude
)
console.log('详细地址：', addressInfo.formattedAddress)
console.log('省市区：', `${addressInfo.province} ${addressInfo.city} ${addressInfo.district}`)
} catch (error) {
console.error('获取地址失败：', error)
}
}
showAddress()注意事项：
- 反向地理编码需要使用第三方地图服务（百度地图、高德地图等）
- 需要申请相应的 API Key
- 坐标系统可能需要转换（WGS84 转 GCJ-02 或 BD-09）
- 注意 API 调用次数限制和费用
案例 3：计算两点之间的距离
javascript
// 计算两点之间的距离（使用 Haversine 公式）
function calculateDistance(lat1, lon1, lat2, lon2) {
const R = 6371 // 地球半径（公里）
const dLat = toRad(lat2 - lat1)
const dLon = toRad(lon2 - lon1)
const a =
Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(toRad(lat1)) * Math.cos(toRad(lat2)) * Math.sin(dLon / 2) * Math.sin(dLon / 2)
const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a))
const distance = R * c // 距离（公里）
return distance
}
function toRad(degrees) {
return degrees * (Math.PI / 180)
}
// 使用示例
navigator.geolocation.getCurrentPosition((position) => {
const userLat = position.coords.latitude
const userLon = position.coords.longitude
// 目标位置（例如：北京天安门）
const targetLat = 39.9042
const targetLon = 116.4074
const distance = calculateDistance(userLat, userLon, targetLat, targetLon)
console.log(`距离目标位置: ${distance.toFixed(2)} 公里`)
})案例 4：实时位置追踪
javascript
class LocationTracker {
constructor() {
this.watchId = null
this.positions = []
}
startTracking() {
if (!navigator.geolocation) {
console.error("浏览器不支持地理定位")
return
}
this.watchId = navigator.geolocation.watchPosition(
(position) => {
this.positions.push({
lat: position.coords.latitude,
lng: position.coords.longitude,
timestamp: position.timestamp,
accuracy: position.coords.accuracy
})
console.log("位置已记录:", this.positions.length)
this.onPositionUpdate(position)
},
(error) => {
console.error("追踪位置失败:", error)
},
{
enableHighAccuracy: true,
timeout: 5000,
maximumAge: 0
}
)
}
stopTracking() {
if (this.watchId !== null) {
navigator.geolocation.clearWatch(this.watchId)
this.watchId = null
console.log("已停止追踪")
}
}
onPositionUpdate(position) {
// 可以在这里更新地图标记、绘制路径等
console.log("当前位置:", position.coords.latitude, position.coords.longitude)
}
getTrack() {
return this.positions
}
clearTrack() {
this.positions = []
}
}
// 使用示例
const tracker = new LocationTracker()
tracker.startTracking()
// 10秒后停止追踪
setTimeout(() => {
tracker.stopTracking()
console.log("追踪记录:", tracker.getTrack())
}, 10000)Geolocation API 调用流程
理解 Geolocation API 的完整调用流程是正确使用该 API 的基础。以下流程图展示了从发起请求到获得结果（或错误）的全过程：
图表渲染中…
watchPosition 持续追踪时序
当需要持续追踪用户位置变化时（如导航、运动轨迹记录），watchPosition 方法会建立一个长连接式的监听机制。以下是完整的交互时序图：
图表渲染中…
权限状态机
Geolocation API 的权限管理遵循严格的状态机模型。理解权限状态转换有助于设计更好的用户体验流程：
图表渲染中…
权限状态说明
| 状态 | 含义 | 行为建议 |
|---|---|---|
prompt | 尚未决定，将弹窗询问 | 准备好解释为什么需要位置信息 |
granted | 已授权，可直接调用 | 正常使用 API，无需额外交互 |
denied | 已拒绝，不会弹窗 | 引导用户到设置中手动开启 |
Geolocation 高级应用
<h4>005-geofencing.html</h4>html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>【5】地理围栏 Geofencing 演示</title>
<!--
来源: HTML5基础知识/16-获取地理位置信息.md
知识点: 地理围栏 — 进入/离开指定半径区域触发通知
-->
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
padding: 20px; background: linear-gradient(135deg, #0c0c1d, #1a1a3e);
color: #e0e0e0; min-height: 100vh;
}
.container { max-width: 1000px; margin: 0 auto; }
.header {
text-align: center; padding: 24px; background: linear-gradient(135deg, #e91e63, #9c27b0);
color: white; border-radius: 12px; margin-bottom: 24px;
}
.header h1 { font-size: 22px; margin-bottom: 6px; }
.header p { opacity: 0.9; font-size: 14px; }
.card {
background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1);
border-radius: 12px; padding: 24px; margin-bottom: 20px; backdrop-filter: blur(10px);
}
.card-title {
font-size: 15px; font-weight: 600; color: #f48fb1;
border-left: 3px solid #e91e63; padding-left: 10px; margin-bottom: 16px;
}
.info-banner {
background: rgba(233,30,99,0.1); border: 1px solid rgba(233,30,99,0.25);
border-radius: 6px; padding: 12px 16px; font-size: 13px; line-height: 1.6;
color: #f8bbd0; margin-bottom: 16px;
}
/* 围栏设置 */
.fence-config { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 14px; margin-bottom: 20px; }
.config-item {
background: rgba(0,0,0,0.25); border: 1px solid rgba(255,255,255,0.08);
border-radius: 8px; padding: 14px;
}
.config-label { font-size: 11px; color: #888; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 6px; }
input[type="number"], input[type="text"] {
width: 100%; padding: 8px 10px; background: rgba(0,0,0,0.4); border: 1px solid #444;
color: #fff; border-radius: 6px; font-size: 13px; font-family: monospace;
}
input:focus { outline: none; border-color: #e91e63; }
.btn {
padding: 11px 26px; border: none; border-radius: 8px; cursor: pointer;
font-size: 14px; font-weight: 600; transition: all 0.2s;
}
.btn-pink { background: linear-gradient(135deg, #e91e63, #9c27b0); color: white; }
.btn-pink:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(233,30,99,0.35); }
.btn-pink:disabled { opacity: 0.4; cursor: not-allowed; }
.btn-red { background: #f44336; color: white; }
.btn-red:hover { background: #da3633; }
/* 地图可视化 */
.map-container {
position: relative; background: #0a0a18; border-radius: 10px;
overflow: hidden; margin-bottom: 16px;
}
canvas { display: block; width: 100%; height: 340px; }
/* 围栏状态 */
.fence-status {
display: flex; align-items: center; gap: 16px; padding: 16px 20px;
background: rgba(0,0,0,0.25); border-radius: 8px; margin-bottom: 16px;
}
.status-indicator {
width: 60px; height: 60px; border-radius: 50%;
display: flex; align-items: center; justify-content: center;
font-size: 28px; transition: all 0.5s;
}
.status-inside { background: rgba(76,175,80,0.2); border: 3px solid #4caf50; box-shadow: 0 0 20px rgba(76,175,80,0.3); }
.status-outside { background: rgba(244,67,54,0.15); border: 3px solid #f44336; }
.status-unknown { background: rgba(158,158,158,0.15); border: 3px solid #9e9e9e; }
.status-text h3 { font-size: 18px; margin-bottom: 4px; }
.status-text p { font-size: 12px; color: #888; }
/* 事件日志 */
.event-log {
background: #0a0a15; border-radius: 6px; padding: 14px;
font-family: monospace; font-size: 11px; max-height: 200px;
overflow-y: auto; color: #777; line-height: 1.7;
}
.event-entry { padding: 4px 8px; margin-bottom: 3px; border-radius: 4px; animation: fadeSlide 0.3s ease; }
@keyframes fadeSlide { from{opacity:0;transform:translateX(-10px)} to{opacity:1;transform:translateX(0)} }
.event-enter { background: rgba(76,175,80,0.12); color: #81c784; border-left: 3px solid #4caf50; }
.event-leave { background: rgba(244,67,54,0.12); color: #e57373; border-left: 3px solid #f44336; }
.event-info { background: rgba(33,150,243,0.08); color: #64b5f6; border-left: 3px solid #2196f3; }
.event-warn { background: rgba(255,152,0,0.08); color: #ffb74d; border-left: 3px solid #ff9800; }
.compat-note {
background: rgba(156,39,176,0.1); border: 1px solid rgba(156,39,176,0.25);
border-radius: 6px; padding: 10px 14px; font-size: 12px; color: #ce93d8;
margin-top: 16px;
}
</style>
</head>
<body>
<div class="container">
<div class="header">
<h1>🚧 地理围栏 Geofencing 演示</h1>
<p>进入 / 离开指定半径区域时自动触发通知</p>
</div>
<div class="card">
<div class="card-title">🎯 围栏配置与监控</div>
<div class="info-banner">
💡 <strong>地理围栏 (Geofencing)</strong> 是基于位置的服务核心功能：设定一个中心点和半径，
当设备进入或离开该圆形区域时触发事件。应用场景：<br>
• 🛒 到店推送优惠 • 🏢 考勤打卡范围检测 • ⚠️ 危险区域警告 • 🎮 基于位置的 AR 游戏
</div>
<!-- 围栏参数设置 -->
<div class="fence-config">
<div class="config-item">
<div class="config-label">目标纬度 (Latitude)</div>
<input type="number" id="fenceLat" value="39.9042" step="0.0001" />
</div>
<div class="config-item">
<div class="config-label">目标经度 (Longitude)</div>
<input type="number" id="fenceLng" value="116.4074" step="0.0001" />
</div>
<div class="config-item">
<div class="config-label">围栏半径 (Radius) 米</div>
<input type="number" id="fenceRadius" value="500" min="10" max="50000" />
</div>
<div class="config-item">
<div class="config-label">围栏名称</div>
<input type="text" id="fenceName" value="天安门广场 (示例)" />
</div>
</div>
<div style="display:flex;gap:10px;margin-bottom:20px;flex-wrap:wrap;">
<button class="btn btn-pink" id="startBtn" onclick="startGeofencing()">🚧 启动围栏监控</button>
<button class="btn btn-red" id="stopBtn" onclick="stopGeofencing()" disabled>⛹ 停止监控</button>
<button class="btn btn-pink" style="background:#7b1fa2;" onclick="useMyLocation()">📍 使用我的位置作为中心</button>
</div>
<!-- 围栏状态 -->
<div class="fence-status">
<div class="status-indicator status-unknown" id="statusIndicator">❓</div>
<div class="status-text">
<h3 id="statusTitle">未开始监控</h3>
<p id="statusDesc">点击 "启动围栏监控" 开始检测您是否在围栏区域内</p>
</div>
</div>
<!-- 地图 -->
<div class="map-container">
<canvas id="geoCanvas"></canvas>
</div>
<!-- 事件日志 -->
<div class="event-log" id="eventLog">
<div class="event-entry event-info">[系统] 地理围栏系统就绪。默认中心: 天安门广场 (39.9042, 116.4074)，半径: 500m</div>
</div>
<div class="compat-note">
ℹ️ <strong>说明：</strong>HTML5 Geolocation API 本身不提供原生的 Geofencing 功能。
此示例通过 <code>watchPosition()</code> + Haversine 公式计算距离来模拟地理围栏。
原生 Geofencing API 曾存在于 Chrome 中但已废弃，推荐使用 Web 方案模拟实现。
</div>
</div>
</div>
<script>
const canvas = document.getElementById('geoCanvas');
const ctx = canvas.getContext('2d');
const logEl = document.getElementById('eventLog');
let watchId = null;
let lastState = null; // 'inside' | 'outside' | null
function log(msg, type) {
const div = document.createElement('div');
div.className = `event-entry ${type}`;
const t = new Date().toTimeString().substring(0,8);
div.textContent = `[${t}] ${msg}`;
logEl.appendChild(div);
logEl.scrollTop = logEl.scrollHeight;
}
// ====== Canvas 绘制 ======
function resizeCanvas() {
canvas.width = canvas.parentElement.clientWidth;
canvas.height = 340;
drawMap();
}
window.addEventListener('resize', resizeCanvas);
function drawMap(userPos = null) {
const w = canvas.width, h = canvas.height;
// 背景
ctx.fillStyle = '#0a0a18';
ctx.fillRect(0, 0, w, h);
// 网格
ctx.strokeStyle = '#1a1a35';
ctx.lineWidth = 1;
for (let x = 0; x < w; x += 50) { ctx.beginPath(); ctx.moveTo(x,0); ctx.lineTo(x,h); ctx.stroke(); }
for (let y = 0; y < h; y += 50) { ctx.beginPath(); ctx.moveTo(0,y); ctx.lineTo(w,y); ctx.stroke(); }
const lat = parseFloat(document.getElementById('fenceLat').value) || 39.9042;
const lng = parseFloat(document.getElementById('fenceLng').value) || 116.4074;
const radius = parseFloat(document.getElementById('fenceRadius').value) || 500;
// 中心点（围栏圆心）— 映射到画布中心
const cx = w / 2, cy = h / 2;
// 将半径映射到像素（假设 1km ≈ 150px）
const pxPerMeter = 0.15;
const rPx = Math.min(radius * pxPerMeter, Math.min(w, h) * 0.42);
// 绘制围栏区域
// 外圈
ctx.beginPath();
ctx.arc(cx, cy, rPx, 0, Math.PI * 2);
ctx.fillStyle = userPos === 'inside'
? 'rgba(76,175,80,0.08)' : userPos === 'outside'
? 'rgba(244,67,54,0.06)' : 'rgba(156,39,176,0.05)';
ctx.fill();
ctx.strokeStyle = userPos === 'inside' ? '#4caf50' : userPos === 'outside' ? '#f44336' : '#9c27b0';
ctx.lineWidth = 2;
ctx.stroke();
// 内圈虚线
ctx.setLineDash([5, 5]);
ctx.beginPath();
ctx.arc(cx, cy, rPx * 0.6, 0, Math.PI * 2);
ctx.strokeStyle = 'rgba(255,255,255,0.08)';
ctx.stroke();
ctx.setLineDash([]);
// 中心标记
ctx.fillStyle = '#9c27b0';
ctx.beginPath();
ctx.arc(cx, cy, 6, 0, Math.PI * 2);
ctx.fill();
// 标签
ctx.font = 'bold 12px system-ui';
ctx.fillStyle = '#ce93d8';
ctx.textAlign = 'center';
ctx.fillText(`🎯 ${document.getElementById('fenceName').value}`, cx, cy - 16);
ctx.font = '11px monospace';
ctx.fillStyle = '#666';
ctx.fillText(`${lat.toFixed(4)}, ${lng.toFixed(4)}`, cx, cy + 28);
ctx.fillText(`半径: ${radius}m`, cx, cy + 44);
// 用户位置
if (userPos && userPos.lat !== undefined) {
// 简单映射：将用户位置相对于中心的偏移量显示
// 实际中需要更复杂的坐标投影
const offsetScale = 3000; // 放大偏移以便观察
let ux = cx + ((userPos.lng - lng) * offsetScale);
let uy = cy - ((userPos.lat - lat) * offsetScale);
// 限制在画布内
ux = Math.max(20, Math.min(w - 20, ux));
uy = Math.max(20, Math.min(h - 20, uy));
// 用户点到围栏的距离（像素）
const distPx = Math.sqrt((ux-cx)**2 + (uy-cy)**2);
// 连线
ctx.beginPath();
ctx.moveTo(cx, cy);
ctx.lineTo(ux, uy);
ctx.strokeStyle = userPos.state === 'inside' ? 'rgba(76,175,80,0.4)' : 'rgba(244,67,54,0.4)';
ctx.lineWidth = 1;
ctx.setLineDash([4, 4]);
ctx.stroke();
ctx.setLineDash([]);
// 用户点
ctx.beginPath();
ctx.arc(ux, uy, 10, 0, Math.PI * 2);
ctx.fillStyle = userPos.state === 'inside' ? '#4caf50' : '#f44336';
ctx.fill();
ctx.strokeStyle = 'white'; ctx.lineWidth = 2; ctx.stroke();
// 距离标注
const realDist = calcDistance(lat, lng, userPos.lat, userPos.lng);
ctx.font = 'bold 11px monospace';
ctx.fillStyle = '#aaa';
ctx.textAlign = 'left';
ctx.fillText(`${realDist.toFixed(0)}m`, ux + 14, uy + 4);
} else {
// 提示
ctx.font = '12px system-ui';
ctx.fillStyle = '#555';
ctx.textAlign = 'center';
ctx.fillText('启动监控后，您的位置将显示在此处', cx, h - 20);
}
}
// ====== Haversine 公式计算两点间距离 ======
function calcDistance(lat1, lon1, lat2, lon2) {
const R = 6371000; // 地球半径 (米)
const dLat = (lat2 - lat1) * Math.PI / 180;
const dLon = (lon2 - lon1) * Math.PI / 180;
const a = Math.sin(dLat/2)**2 +
Math.cos(lat1*Math.PI/180) * Math.cos(lat2*Math.PI/180) *
Math.sin(dLon/2)**2;
return R * 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
}
function updateStatus(state) {
const indicator = document.getElementById('statusIndicator');
const title = document.getElementById('statusTitle');
const desc = document.getElementById('statusDesc');
if (state === 'inside') {
indicator.className = 'status-indicator status-inside';
indicator.textContent = '✅';
title.textContent = '🎉 您在围栏区域内！';
title.style.color = '#4caf50';
desc.textContent = `当前位于 "${document.getElementById('fenceName').value}" 的监控范围内`;
} else if (state === 'outside') {
indicator.className = 'status-indicator status-outside';
indicator.textContent = '📍';
title.textContent = '📍 您在围栏区域外';
title.style.color = '#f44336';
desc.textContent = `距离围栏中心还有一定距离`;
} else {
indicator.className = 'status-indicator status-unknown';
indicator.textContent = '❓';
title.textContent = '等待定位...';
title.style.color = '#9e9e9e';
desc.textContent = '';
}
}
// ====== 控制函数 ======
function startGeofencing() {
if (!navigator.geolocation) {
log('❌ 浏览器不支持 Geolocation', 'warn'); return;
}
document.getElementById('startBtn').disabled = true;
document.getElementById('stopBtn').disabled = false;
lastState = null;
const fenceLat = parseFloat(document.getElementById('fenceLat').value);
const fenceLng = parseFloat(document.getElementById('fenceLng').value);
const fenceRadius = parseFloat(document.getElementById('fenceRadius').value);
log(`🚧 围栏已启用: 中心(${fenceLat}, ${fenceLng}) | 半径:${fenceRadius}m | 名称: "${document.getElementById('fenceName').value}"`, 'info');
updateStatus(null);
resizeCanvas();
watchId = navigator.geolocation.watchPosition(
function(pos) {
const c = pos.coords;
const distance = calcDistance(fenceLat, fenceLng, c.latitude, c.longitude);
const currentState = distance <= fenceRadius ? 'inside' : 'outside';
// 更新地图
drawMap({ lat: c.latitude, lng: c.longitude, state: currentState });
// 检测状态变化
if (lastState !== currentState) {
if (currentState === 'inside') {
log(`🟢 进入围栏! 距离中心: ${distance.toFixed(0)}m ≤ 半径: ${fenceRadius}m`, 'enter');
} else {
log(`🔴 离开围栏! 距离中心: ${distance.toFixed(0)}m > 半径: ${fenceRadius}m`, 'leave');
}
lastState = currentState;
}
updateStatus(currentState);
},
function(err) {
const msgs = { 1:'权限被拒绝', 2:'位置不可用', 3:'超时' };
log(`❌ 定位错误 [${err.code}]: ${msgs[err.code] || err.message}`, 'warn');
},
{ enableHighAccuracy: true, timeout: 15000, maximumAge: 5000 }
);
}
function stopGeofencing() {
if (watchId !== null) {
navigator.geolocation.clearWatch(watchId);
watchId = null;
}
document.getElementById('startBtn').disabled = false;
document.getElementById('stopBtn').disabled = true;
updateStatus(null);
log('⛹ 围栏监控已停止', 'info');
// 重绘地图（无用户位置）
drawMap();
}
function useMyLocation() {
if (!navigator.geolocation) return;
log('📍 正在获取当前位置...', 'info');
navigator.geolocation.getCurrentPosition(
function(pos) {
document.getElementById('fenceLat').value = pos.coords.latitude.toFixed(6);
document.getElementById('fenceLng').value = pos.coords.longitude.toFixed(2);
log(`✅ 已设为当前位置: (${pos.coords.latitude.toFixed(6)}, ${pos.coords.longitude.toFixed(6)})`, 'enter');
drawMap();
},
function(err) { log(`获取失败: code=${err.code}`, 'warn'); },
{ enableHighAccuracy: true, timeout: 10000 }
);
}
// 初始化 Canvas
resizeCanvas();
</script>
</body>
</html>地理围栏 Geofencing
地理围栏（Geofencing）是一种虚拟边界技术，当设备进入、离开或停留在特定地理区域时触发相应事件。虽然浏览器原生尚未提供标准 Geofencing API，但我们可以基于 watchPosition 自行实现。
围栏核心实现
javascript
/**
* 地理围栏管理器
* 支持圆形围栏的进入/离开/停留检测
*/
class GeofenceManager {
constructor(options = {}) {
this.fences = new Map() // 围栏集合
this.watchId = null
this.lastPosition = null
this.insideFences = new Set() // 当前处于内部的围栏 ID
this.dwellTimers = new Map() // 停留计时器
this.options = {
dwellTime: options.dwellTime || 3000, // 停留判定时间（ms）
updateInterval: options.updateInterval || 2000, // 位置更新间隔
...options
}
}
/**
* 添加圆形地理围栏
* @param {string} id - 围栏唯一标识
* @param {number} latitude - 圆心纬度
* @param {number} longitude - 圆心经度
* @param {number} radius - 半径（米）
* @param {object} callbacks - 回调函数集合
*/
addFence(id, latitude, longitude, radius, callbacks = {}) {
this.fences.set(id, {
id,
center: { latitude, longitude },
radius,
onEnter: callbacks.onEnter || (() => {}),
onExit: callbacks.onExit || (() => {}),
onDwell: callbacks.onDwell || (() => {})
})
console.log(`[Geofence] 围栏已添加: ${id}, 半径: ${radius}m`)
return this
}
/**
* 移除指定围栏
*/
removeFence(id) {
this.fences.delete(id)
this.insideFences.delete(id)
if (this.dwellTimers.has(id)) {
clearTimeout(this.dwellTimers.get(id))
this.dwellTimers.delete(id)
}
console.log(`[Geofence] 围栏已移除: ${id}`)
}
/**
* 计算 Haversine 距离（米）
*/
_distanceToCenter(lat1, lon1, lat2, lon2) {
const R = 6371000 // 地球半径（米）
const dLat = (lat2 - lat1) * Math.PI / 180
const dLon = (lon2 - lon1) * Math.PI / 180
const a =
Math.sin(dLat / 2) ** 2 +
Math.cos(lat1 * Math.PI / 180) *
Math.cos(lat2 * Math.PI / 180) *
Math.sin(dLon / 2) ** 2
const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a))
return R * c
}
/**
* 检测单个围栏状态
*/
_checkFence(fence, currentLat, currentLng) {
const distance = this._distanceToCenter(
currentLat, currentLng,
fence.center.latitude, fence.center.longitude
)
const isInside = distance <= fence.radius
const wasInside = this.insideFences.has(fence.id)
if (isInside && !wasInside) {
// 进入围栏
this.insideFences.add(fence.id)
console.log(`[Geofence] 🟢 进入围栏: ${fence.id}, 距中心: ${Math.round(distance)}m`)
fence.onEnter({ fenceId: fence.id, distance, position: this.lastPosition })
// 启动停留计时
this.dwellTimers.set(fence.id, setTimeout(() => {
if (this.insideFences.has(fence.id)) {
console.log(`[Geofence] 🔵 停留围栏: ${fence.id}`)
fence.onDwell({ fenceId: fence.id, dwellTime: this.options.dwellTime })
}
}, this.options.dwellTime))
} else if (!isInside && wasInside) {
// 离开围栏
this.insideFences.delete(fence.id)
console.log(`[Geofence] 🔴 离开围栏: ${fence.id}`)
fence.onExit({ fenceId: fence.id, distance, position: this.lastPosition })
// 取消停留计时
if (this.dwellTimers.has(fence.id)) {
clearTimeout(this.dwellTimers.get(fence.id))
this.dwellTimers.delete(fence.id)
}
}
}
/**
* 启动围栏监控
*/
start() {
if (this.watchId !== null) {
console.warn("[Geofence] 监控已在运行中")
return
}
if (!navigator.geolocation) {
console.error("[Geofence] 浏览器不支持地理定位")
return
}
this.watchId = navigator.geolocation.watchPosition(
(position) => {
this.lastPosition = position
const { latitude, longitude } = position.coords
// 检测所有围栏
this.fences.forEach((fence) => {
this._checkFence(fence, latitude, longitude)
})
},
(error) => {
console.error("[Geofence] 定位错误:", error.message)
},
{
enableHighAccuracy: true,
timeout: 10000,
maximumAge: 0
}
)
console.log(`[Geofence] 监控已启动, 共 ${this.fences.size} 个围栏`)
}
/**
* 停止围栏监控
*/
stop() {
if (this.watchId !== null) {
navigator.geolocation.clearWatch(this.watchId)
this.watchId = null
}
// 清理所有停留计时器
this.dwellTimers.forEach((timer) => clearTimeout(timer))
this.dwellTimers.clear()
console.log("[Geofence] 监控已停止")
}
}地理围栏使用示例
javascript
// 创建围栏管理器
const geofenceManager = new GeofenceManager({ dwellTime: 5000 })
// 添加公司围栏（进入打卡提醒）
geofenceManager.addFence(
"company",
39.984153, 116.307490, // 北京某公司坐标
200, // 半径 200 米
{
onEnter: ({ fenceId, distance }) => {
showNotification("欢迎回到公司", `您已进入公司范围 (${Math.round(distance)}m)`)
triggerCheckInButton()
},
onExit: ({ fenceId }) => {
showNotification("离开公司", "您已离开公司范围")
},
onDwell: ({ fenceId }) => {
console.log("已在公司停留超过 5 秒")
}
}
)
// 添加家周围围栏
geofenceManager.addFence(
"home",
39.904200, 116.407400, // 北京天安门附近（示例）
500,
{
onEnter: () => {
showNotification("到家了", "欢迎回家！")
},
onExit: () => {
sendLeaveHomeNotification()
}
}
)
// 启动监控
geofenceManager.start()
// 1小时后停止
setTimeout(() => geofenceManager.stop(), 3600000)轨迹记录与路径绘制
结合 Leaflet 开源地图库实现运动轨迹的实时记录与可视化展示：
javascript
/**
* 轨迹记录器 - 整合 Leaflet 地图
* 需要先引入 Leaflet CSS/JS:
* <link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css" />
* <script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js"></script>
*/
class TrackRecorder {
constructor(mapContainerId, options = {}) {
this.trackPoints = []
this.watchId = null
this.isRecording = false
this.polyline = null
this.marker = null
this.options = {
lineColor: options.lineColor || '#e74c3c',
lineWeight: options.lineWeight || 4,
maxPoints: options.maxPoints || 1000,
...options
}
// 初始化地图
this.map = L.map(mapContainerId).setView([39.9042, 116.4074], 13)
L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
attribution: '© OpenStreetMap contributors'
}).addTo(this.map)
}
startRecording() {
if (this.isRecording) return
this.isRecording = true
this.trackPoints = []
// 清除之前的轨迹线
if (this.polyline) {
this.map.removeLayer(this.polyline)
this.polyline = null
}
this.watchId = navigator.geolocation.watchPosition(
(position) => {
const { latitude, longitude, accuracy } = position.coords
const point = {
lat: latitude,
lng: longitude,
accuracy,
timestamp: position.timestamp,
time: new Date(position.timestamp).toLocaleTimeString()
}
this.trackPoints.push(point)
// 更新轨迹线
this._updatePolyline()
// 更新当前位置标记
this._updateMarker(latitude, longitude)
// 自动平移地图视角
this.map.panTo([latitude, longitude])
// 触发外部回调
if (this.onPointAdded) {
this.onPointAdded(point, this.trackPoints.length)
}
// 限制最大点数
if (this.trackPoints.length > this.options.maxPoints) {
this.trackPoints.shift()
}
},
(error) => {
console.error("轨迹记录失败:", error.message)
this.stopRecording()
},
{
enableHighAccuracy: true,
timeout: 10000,
maximumAge: 0
}
)
}
_updatePolyline() {
const latLngs = this.trackPoints.map(p => [p.lat, p.lng])
if (this.polyline) {
this.polyline.setLatLngs(latLngs)
} else {
this.polyline = L.polyline(latLngs, {
color: this.options.lineColor,
weight: this.options.lineWeight,
opacity: 0.8
}).addTo(this.map)
}
}
_updateMarker(lat, lng) {
if (this.marker) {
this.marker.setLatLng([lat, lng])
} else {
// 创建带脉冲动画的自定义图标
const pulseIcon = L.divIcon({
className: 'custom-marker',
html: '<div class="pulse-ring"></div><div class="marker-dot"></div>',
iconSize: [24, 24],
iconAnchor: [12, 12]
})
this.marker = L.marker([lat, lng], { icon: pulseIcon }).addTo(this.map)
}
}
stopRecording() {
if (this.watchId !== null) {
navigator.geolocation.clearWatch(this.watchId)
this.watchId = null
}
this.isRecording = false
return this.getTrackSummary()
}
getTrackSummary() {
if (this.trackPoints.length < 2) {
return { points: this.trackPoints, totalDistance: 0, duration: 0 }
}
let totalDistance = 0
for (let i = 1; i < this.trackPoints.length; i++) {
totalDistance += this._haversine(
this.trackPoints[i - 1].lat, this.trackPoints[i - 1].lng,
this.trackPoints[i].lat, this.trackPoints[i].lng
)
}
const startTime = this.trackPoints[0].timestamp
const endTime = this.trackPoints[this.trackPoints.length - 1].timestamp
const duration = (endTime - startTime) / 1000 // 秒
return {
points: this.trackPoints,
pointCount: this.trackPoints.length,
totalDistance: Math.round(totalDistance),
duration: Math.round(duration),
avgSpeed: duration > 0 ? Math.round(totalDistance / duration * 3.6) : 0 // km/h
}
}
_haversine(lat1, lon1, lat2, lon2) {
const R = 6371000
const dLat = (lat2 - lat1) * Math.PI / 180
const dLon = (lon2 - lon1) * Math.PI / 180
const a = Math.sin(dLat / 2) ** 2 +
Math.cos(lat1 * Math.PI / 180) * Math.cos(lat2 * Math.PI / 180) *
Math.sin(dLon / 2) ** 2
return R * 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a))
}
exportGPX() {
if (this.trackPoints.length === 0) return ''
let gpx = '<?xml version="1.0" encoding="UTF-8"?>\n'
gpx += '<gpx version="1.1" creator="TrackRecorder">\n'
gpx += '<trk><trkseg>\n'
this.trackPoints.forEach(p => {
gpx += `<trkpt lat="${p.lat}" lon="${p.lng}">\n`
gpx += `<time>${new Date(p.timestamp).toISOString()}</time>\n`
gpx += '</trkpt>\n'
})
gpx += '</trkseg></trk>\n</gpx>'
return gpx
}
destroy() {
this.stopRecording()
if (this.map) {
this.map.remove()
}
}
}轨迹记录 HTML 完整示例
html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>运动轨迹记录</title>
<link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css" />
<style>
#map { height: 400px; width: 100%; }
.controls { padding: 15px; background: #f8f9fa; display: flex; gap: 10px; align-items: center; }
.stats { padding: 15px; background: #fff; border-top: 1px solid #eee; display: flex; gap: 20px; }
.stat-item { text-align: center; }
.stat-value { font-size: 24px; font-weight: bold; color: #333; }
.stat-label { font-size: 12px; color: #999; }
button { padding: 8px 16px; cursor: pointer; border-radius: 4px; border: none; }
.btn-start { background: #27ae60; color: white; }
.btn-stop { background: #e74c3c; color: white; }
.btn-export { background: #3498db; color: white; }
.recording-indicator {
width: 12px; height: 12px; background: #e74c3c;
border-radius: 50%; animation: pulse 1s infinite;
}
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.3; } }
</style>
</head>
<body>
<div class="controls">
<button id="startBtn" class="btn-start" onclick="toggleRecording()">开始记录</button>
<button id="exportBtn" class="btn-export" onclick="exportTrack()" disabled>导出 GPX</button>
<span id="statusIndicator" style="display:none;"><span class="recording-indicator"></span> 记录中...</span>
</div>
<div id="map"></div>
<div class="stats">
<div class="stat-item"><div class="stat-value" id="pointCount">0</div><div class="stat-label">采样点</div></div>
<div class="stat-item"><div class="stat-value" id="totalDist">0 m</div><div class="stat-label">总距离</div></div>
<div class="stat-item"><div class="stat-value" id="duration">0s</div><div class="stat-label">时长</div></div>
<div class="stat-item"><div class="stat-value" id="avgSpeed">0</div><div class="stat-label">平均时速(km/h)</div></div>
</div>
<script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js"></script>
<script>
let recorder = null
function initRecorder() {
recorder = new TrackRecorder('map', {
lineColor: '#e74c3c',
lineWeight: 4
})
recorder.onPointAdded = (point, count) => {
document.getElementById('pointCount').textContent = count
}
}
function toggleRecording() {
const btn = document.getElementById('startBtn')
const indicator = document.getElementById('statusIndicator')
const exportBtn = document.getElementById('exportBtn')
if (!recorder.isRecording) {
recorder.startRecording()
btn.textContent = '停止记录'
btn.className = 'btn-stop'
indicator.style.display = 'inline-flex'
} else {
const summary = recorder.stopRecording()
btn.textContent = '开始记录'
btn.className = 'btn-start'
indicator.style.display = 'none'
exportBtn.disabled = false
// 显示最终统计数据
document.getElementById('totalDist').textContent = summary.totalDistance + ' m'
document.getElementById('duration').textContent = summary.duration + 's'
document.getElementById('avgSpeed').textContent = summary.avgSpeed
}
}
function exportTrack() {
const gpx = recorder.exportGPX()
const blob = new Blob([gpx], { type: 'application/gpx+xml' })
const url = URL.createObjectURL(blob)
const a = document.createElement('a')
a.href = url
a.download = `track-${Date.now()}.gpx`
a.click()
URL.revokeObjectURL(url)
}
// 页面加载完成后初始化
window.addEventListener('load', () => {
// 先加载 TrackRecorder 类定义（上面的类定义需要先引入）
initRecorder()
})
</script>
</body>
</html>位置变化节流与防抖策略
在使用 watchPosition 时，位置回调频率可能非常高（某些设备每秒可达数次），这会导致不必要的性能开销和网络请求。节流（Throttle）和防抖（Debounce）是两种经典的频率控制策略：
javascript
/**
* 位置更新频率控制器
* 提供节流、防抖、距离过滤等多种策略
*/
class LocationUpdateController {
constructor(options = {}) {
this.options = {
throttleInterval: options.throttleInterval || 2000, // 节流间隔(ms)
debounceDelay: options.debounceDelay || 3000, // 防抖延迟(ms)
minDistance: options.minDistance || 10, // 最小移动距离(m)
...options
}
this.lastUpdateTime = 0
this.debounceTimer = null
this.lastPosition = null
}
/**
* 策略一：节流 (Throttle)
* 保证在指定时间间隔内最多执行一次回调
*/
throttle(callback) {
return (position) => {
const now = Date.now()
if (now - this.lastUpdateTime >= this.options.throttleInterval) {
this.lastUpdateTime = now
this.lastPosition = position
callback(position)
}
}
}
/**
* 策略二：防抖 (Debounce)
* 在位置停止变化一段时间后才执行回调
* 适用于"用户停止移动后再上报"的场景
*/
debounce(callback) {
return (position) => {
if (this.debounceTimer) {
clearTimeout(this.debounceTimer)
}
this.debounceTimer = setTimeout(() => {
this.lastPosition = position
callback(position)
}, this.options.debounceDelay)
}
}
/**
* 策略三：距离过滤 (Distance Filter)
* 只有当移动距离超过阈值时才触发回调
* 有效过滤 GPS 抖动噪声
*/
filterByDistance(callback) {
return (position) => {
if (!this.lastPosition) {
this.lastPosition = position
callback(position)
return
}
const dist = this._calculateDistance(
this.lastPosition.coords.latitude,
this.lastPosition.coords.longitude,
position.coords.latitude,
position.coords.longitude
)
if (dist >= this.options.minDistance) {
this.lastPosition = position
callback(position, dist)
}
}
}
/**
* 策略四：组合策略（推荐生产环境使用）
* 同时应用节流 + 距离过滤
*/
combined(callback) {
const throttled = this.throttle((pos) => {
// 节流通过后，再进行距离过滤
if (!this._lastCombinedPos) {
this._lastCombinedPos = pos
callback(pos)
return
}
const dist = this._calculateDistance(
this._lastCombinedPos.coords.latitude,
this._lastCombinedPos.coords.longitude,
pos.coords.latitude,
pos.coords.longitude
)
if (dist >= this.options.minDistance) {
this._lastCombinedPos = pos
callback(pos, dist)
}
})
return throttled
}
_calculateDistance(lat1, lon1, lat2, lon2) {
const R = 6371000
const dLat = (lat2 - lat1) * Math.PI / 180
const dLon = (lon2 - lon1) * Math.PI / 180
const a = Math.sin(dLat / 2) ** 2 +
Math.cos(lat1 * Math.PI / 180) * Math.cos(lat2 * Math.PI / 180) *
Math.sin(dLon / 2) ** 2
return R * 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a))
}
reset() {
this.lastUpdateTime = 0
this.lastPosition = null
this._lastCombinedPos = null
if (this.debounceTimer) {
clearTimeout(this.debounceTimer)
this.debounceTimer = null
}
}
}使用示例对比
javascript
const controller = new LocationUpdateController({
throttleInterval: 2000, // 最多每2秒一次
debounceDelay: 3000, // 停止移动3秒后触发
minDistance: 15 // 至少移动15米
})
// 方式1: 纯节流 - 适合实时导航
const throttledHandler = controller.throttle((position) => {
updateNavigationUI(position.coords)
})
navigator.geolocation.watchPosition(throttledHandler, handleError, trackingOptions)
// 方式2: 纯防抖 - 适合签到/打卡场景
const debouncedHandler = controller.debounce((position) => {
submitCheckInLocation(position.coords)
})
// 方式3: 距离过滤 - 适合轨迹记录
const filteredHandler = controller.filterByDistance((position, distance) => {
addTrackPoint(position.coords, distance)
})
// 方式4: 组合策略（推荐）- 适合大多数场景
const combinedHandler = controller.combined((position, distance) => {
// 这里保证: 每2秒内最多1次 且 移动超过15米才触发
uploadPositionToServer(position.coords)
updateMapMarker(position.coords)
})
navigator.geolocation.watchPosition(combinedHandler, handleError, trackingOptions)后台持续定位
Web 应用的后台定位能力受限于浏览器的生命周期管理，但可以通过以下策略实现近似效果：
javascript
/**
* 后台定位管理器
* 利用 Page Visibility API + Service Worker + Background Sync 实现降级方案
*/
class BackgroundLocationService {
constructor(options = {}) {
this.options = {
foregroundInterval: options.foregroundInterval || 5000, // 前台更新间隔
backgroundInterval: options.backgroundInterval || 30000, // 后台更新间隔
maxBackgroundDuration: options.maxBackgroundDuration || 3600000, // 最大后台时长
...options
}
this.watchId = null
this.isForeground = !document.hidden
this.startTime = Date.now()
this.positionCache = []
}
async start() {
// 注册 Service Worker 用于后台同步
await this._registerServiceWorker()
// 注册 Background Sync
await this._registerBackgroundSync()
// 启动前台定位
this._startForegroundTracking()
// 监听页面可见性变化
document.addEventListener('visibilitychange', () => this._onVisibilityChange())
// 监听来自 SW 的消息
navigator.serviceWorker?.addEventListener('message', (event) => {
if (event.data.type === 'BACKGROUND_LOCATION') {
this._handleBackgroundPosition(event.data.position)
}
})
}
_startForegroundTracking() {
this.watchId = navigator.geolocation.watchPosition(
(position) => {
this._cachePosition(position, 'foreground')
this._broadcastPosition(position)
},
(error) => console.error('前台定位错误:', error),
{
enableHighAccuracy: this.isForeground,
timeout: this.options.foregroundInterval,
maximumAge: 0
}
)
}
_stopForegroundTracking() {
if (this.watchId !== null) {
navigator.geolocation.clearWatch(this.watchId)
this.watchId = null
}
}
_onVisibilityChange() {
const nowHidden = document.hidden
if (nowHidden === this.isForeground) return
this.isForeground = !nowHidden
if (nowHidden) {
// 进入后台
console.log('[BgLocation] 进入后台模式')
this._stopForegroundTracking()
// 尝试使用 Web Worker 保持定时器运行
this._startBackgroundWorker()
// 保存最后已知位置到 IndexedDB
this._saveLastKnownPosition()
} else {
// 回到前台
console.log('[BgLocation] 回到前台模式')
this._stopBackgroundWorker()
this._startForegroundTracking()
// 从 IndexedDB 恢复位置
this._restorePositions()
}
}
_startBackgroundWorker() {
// 创建内联 Worker 来维持定时任务
const workerCode = `
let intervalId = null
self.onmessage = function(e) {
if (e.data.command === 'start') {
intervalId = setInterval(() => {
self.postMessage({ type: 'tick', time: Date.now() })
}, e.data.interval)
} else if (e.data.command === 'stop') {
if (intervalId) clearInterval(intervalId)
}
}
`
const blob = new Blob([workerCode], { type: 'application/javascript' })
this.bgWorker = new Worker(URL.createObjectURL(blob))
this.bgWorker.onmessage = (e) => {
if (e.data.type === 'tick') {
// 定时触发，尝试获取位置
this._attemptBackgroundFetch()
}
}
this.bgWorker.postMessage({
command: 'start',
interval: this.options.backgroundInterval
})
}
_stopBackgroundWorker() {
if (this.bgWorker) {
this.bgWorker.postMessage({ command: 'stop' })
this.bgWorker.terminate()
this.bgWorker = null
}
}
async _attemptBackgroundFetch() {
// 注意：大部分浏览器在后台会限制 Geolocation
// 这是一种尽力而为的策略
try {
const position = await new Promise((resolve, reject) => {
const timer = setTimeout(() => reject(new Error('timeout')), 5000)
navigator.geolocation.getCurrentPosition(
(pos) => { clearTimeout(timer); resolve(pos) },
(err) => { clearTimeout(timer); reject(err) },
{ enableHighAccuracy: false, timeout: 5000, maximumAge: 60000 }
)
})
this._cachePosition(position, 'background')
} catch (err) {
// 后台获取失败是预期行为，静默处理
console.debug('[BgLocation] 后台定位尝试失败（正常）')
}
}
async _registerServiceWorker() {
if ('serviceWorker' in navigator) {
try {
const swUrl = '/sw-geolocation.js'
// 如果已有 SW 文件则注册，否则跳过
// 实际项目中应预先创建 sw-geolocation.js
// await navigator.serviceWorker.register(swUrl)
console.log('[BgLocation] Service Worker 就绪')
} catch (err) {
console.warn('[BgLocation] SW 注册失败:', err)
}
}
}
async _registerBackgroundSync() {
if ('serviceWorker' in navigator && 'SyncManager' in window) {
try {
const reg = await navigator.serviceWorker.ready
await reg.sync.register('location-sync')
console.log('[BgLocation] Background Sync 已注册')
} catch (err) {
console.warn('[BgLocation] Background Sync 注册失败:', err)
}
}
}
_cachePosition(position, source) {
const entry = {
source,
latitude: position.coords.latitude,
longitude: position.coords.longitude,
accuracy: position.coords.accuracy,
timestamp: position.timestamp
}
this.positionCache.push(entry)
// 保留最近 1000 条
if (this.positionCache.length > 1000) {
this.positionCache.shift()
}
}
_handleBackgroundPosition(position) {
console.log('[BgLocation] 收到后台位置:', position)
this._cachePosition(position, 'background-worker')
}
_broadcastPosition(position) {
// 自定义事件广播
window.dispatchEvent(new CustomEvent('locationUpdate', {
detail: { position, isForeground: this.isForeground }
}))
}
async _saveLastKnownPosition() {
// 使用 IndexedDB 存储最后位置
if ('indexedDB' in window) {
// 简化版：使用 localStorage 作为降级方案
const lastPos = this.positionCache[this.positionCache.length - 1]
if (lastPos) {
localStorage.setItem('geo_last_position', JSON.stringify(lastPos))
}
}
}
getStatistics() {
const fgCount = this.positionCache.filter(p => p.source === 'foreground').length
const bgCount = this.positionCache.filter(p => p.source === 'background').length
return {
totalPoints: this.positionCache.length,
foregroundPoints: fgCount,
backgroundPoints: bgCount,
duration: Date.now() - this.startTime
}
}
stop() {
this._stopForegroundTracking()
this._stopBackgroundWorker()
document.removeEventListener('visibilitychange', this._onVisibilityBinded)
}
}后台定位限制说明
| 平台 | 后台行为 | 说明 |
|---|---|---|
| Chrome Desktop | 标签页后台后暂停 JS 执行 | 定位回调不再触发 |
| Chrome Android | 一段时间后限制定时器 | 可短暂保持，约 5 分钟后受限 |
| iOS Safari | 后台极快冻结 | 几乎立即暂停 |
| Firefox | 类似 Chrome | 取决于具体版本 |
建议方案：
- 对于强需求的后台定位场景，考虑使用 PWA + 原生插件 或 Capacitor/Cordova
- 对于弱需求的场景，利用 Page Visibility API 在前后台切换时调整策略即可
- 利用 Background Sync API 在网络恢复时批量同步缓存的位置数据
主流地图 SDK 集成示例
在实际开发中，通常需要将 Geolocation API 获取的原始坐标对接到第三方地图 SDK 中进行展示和分析。以下提供三大主流地图 SDK 的完整集成示例。
高德地图 SDK 集成
高德地图是国内最常用的地图服务之一，其 JavaScript API 与 Geolocation API 结合非常紧密。
html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>高德地图 + Geolocation 集成</title>
<style>
#container { width: 100%; height: 500px; }
.info-panel { padding: 15px; background: #f0f0f0; margin-bottom: 10px; font-size: 14px; }
.btn-group { padding: 10px; }
button { padding: 8px 16px; margin-right: 8px; cursor: pointer; }
</style>
</head>
<body>
<div class="info-panel" id="infoPanel">正在加载高德地图...</div>
<div class="btn-group">
<button onclick="locateMe()">定位我的位置</button>
<button onclick="startTrack()">开始追踪</button>
<button onclick="stopTrack()">停止追踪</button>
<button onclick="reverseGeocode()">反向地理编码</button>
</div>
<div id="container"></div>
<!-- 引入高德地图 JS API -->
<script src="https://webapi.amap.com/maps?v=2.0&key=YOUR_AMAP_KEY"></script>
<script>
let map = null
let marker = null
let watchId = null
let polyline = null
let trackPoints = []
function initMap() {
map = new AMap.Map('container', {
zoom: 15,
center: [116.397428, 39.90923] // 默认北京
})
document.getElementById('infoPanel').textContent = '地图加载完成，点击按钮开始定位'
}
// 获取当前位置并在地图上显示
async function locateMe() {
if (!navigator.geolocation) {
alert('您的浏览器不支持地理定位')
return
}
try {
const position = await new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject, {
enableHighAccuracy: true,
timeout: 10000,
maximumAge: 0
})
})
const lng = position.coords.longitude
const lat = position.coords.latitude
const acc = position.coords.accuracy
// 注意：浏览器 Geolocation 返回 WGS84 坐标，
// 高德地图使用 GCJ-02 坐标系，需要进行转换
// 这里简化处理，实际项目需做坐标转换
// 创建/更新标记
if (marker) {
marker.setPosition([lng, lat])
} else {
marker = new AMap.Marker({
position: [lng, lat],
title: '我的位置',
animation: 'AMAP_ANIMATION_BOUNCE'
})
map.add(marker)
}
// 设置地图中心和缩放
map.setCenter([lng, lat])
map.setZoom(16)
// 绘制精度圆圈
new AMap.Circle({
center: [lng, lat],
radius: acc,
fillColor: '#1791fc',
fillOpacity: 0.15,
strokeColor: '#1791fc',
strokeOpacity: 0.4,
strokeWeight: 1
}).addTo(map)
// 更新信息面板
document.getElementById('infoPanel').innerHTML = `
<strong>定位成功</strong><br>
坐标: ${lat.toFixed(6)}, ${lng.toFixed(6)}<br>
精度: ±${acc.toFixed(0)} 米
`
} catch (error) {
handleGeolocationError(error)
}
}
// 开始追踪位置
function startTrack() {
if (watchId !== null) {
alert('已经在追踪中')
return
}
trackPoints = []
if (polyline) {
map.remove(polyline)
polyline = null
}
watchId = navigator.geolocation.watchPosition(
(position) => {
const lng = position.coords.longitude
const lat = position.coords.latitude
trackPoints.push([lng, lat])
// 更新标记
if (marker) {
marker.setPosition([lng, lat])
} else {
marker = new AMap.Marker({ position: [lng, lat] })
map.add(marker)
}
// 绘制轨迹线
if (polyline) {
polyline.setPath(trackPoints)
} else {
polyline = new AMap.Polyline({
path: trackPoints,
strokeColor: '#e74c3c',
strokeWeight: 4,
strokeOpacity: 0.8
})
map.add(polyline)
}
// 自动跟随
map.setCenter([lng, lat])
},
(error) => handleGeolocationError(error),
{ enableHighAccuracy: true, timeout: 5000, maximumAge: 0 }
)
document.getElementById('infoPanel').textContent = '📍 正在追踪位置... (点"停止追踪"结束)'
}
// 停止追踪
function stopTrack() {
if (watchId !== null) {
navigator.geolocation.clearWatch(watchId)
watchId = null
document.getElementById('infoPanel').innerHTML =
`追踪已停止，共记录 ${trackPoints.length} 个位置点`
}
}
// 反向地理编码
async function reverseGeocode() {
if (!marker) {
alert('请先定位')
return
}
const pos = marker.getPosition()
AMap.plugin('AMap.Geocoder', () => {
const geocoder = new AMap.Geocoder({})
geocoder.getAddress([pos.lng, pos.lat], (status, result) => {
if (status === 'complete' && result.regeocode) {
document.getElementById('infoPanel').innerHTML = `
<strong>地址解析结果:</strong><br>
${result.regeocode.formattedAddress}<br>
<small>${result.regeocode.addressComponent.province}
${result.regeocode.addressComponent.city}
${result.regeocode.addressComponent.district}</small>
`
}
})
})
}
function handleGeolocationError(error) {
const messages = {
[error.PERMISSION_DENIED]: '用户拒绝了位置请求',
[error.POSITION_UNAVAILABLE]: '无法获取位置信息',
[error.TIMEOUT]: '获取位置超时'
}
document.getElementById('infoPanel').textContent =
'定位失败: ' + (messages[error.code] || error.message)
}
// 初始化地图
initMap()
</script>
</body>
</html>百度地图 SDK 集成
百度地图使用 BD-09 坐标系，从 WGS84 到 BD-09 需要经过两步转换（WGS84 → GCJ-02 → BD-09）：
html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>百度地图 + Geolocation 集成</title>
<style>
#bmap { width: 100%; height: 500px; }
.panel { padding: 10px; background: #f5f5f5; margin-bottom: 5px; }
</style>
</head>
<body>
<div class="panel" id="statusPanel">加载中...</div>
<div id="bmap"></div>
<script src="https://api.map.baidu.com/api?v=3.0&ak=YOUR_BAIDU_AK"></script>
<script>
let bmap = null
let bmarker = null
let bwatchId = null
// WGS84 -> BD-09 坐标转换（两步法）
function wgs84ToBd09(lng, lat) {
// 第一步: WGS84 -> GCJ-02
let x_pi = Math.PI * 3000.0 / 180.0
let z = Math.sqrt(lng * lng + lat * lat) + 0.00002 * Math.sin(lat * x_pi)
let theta = Math.atan2(lat, lng) + 0.000003 * Math.cos(lng * x_pi)
let gcj_lng = z * Math.cos(theta) + 0.0065
let gcj_lat = z * Math.sin(theta) + 0.006
// 第二步: GCJ-02 -> BD-09
z = Math.sqrt(gcj_lng * gcj_lng + gcj_lat * gcj_lat) + 0.00002 * Math.sin(gcj_lat * x_pi)
theta = Math.atan2(gcj_lat, gcj_lng) + 0.000003 * Math.cos(gcj_lng * x_pi)
let bd_lng = z * Math.cos(theta) + 0.0065
let bd_lat = z * Math.sin(theta) + 0.006
return { lng: bd_lng, lat: bd_lat }
}
function initBaiduMap() {
bmap = new BMap.Map('bmap')
bmap.centerAndZoom(new BMap.Point(116.404, 39.915), 15)
bmap.enableScrollWheelZoom()
document.getElementById('statusPanel').textContent = '百度地图就绪'
}
async function locateOnBaiduMap() {
try {
const pos = await new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject, {
enableHighAccuracy: true, timeout: 10000
})
})
// 浏览器返回的是 WGS84 坐标，转换为百度 BD-09
const bd = wgs84ToBd09(pos.coords.longitude, pos.coords.latitude)
const point = new BMap.Point(bd.lng, bd.lat)
// 显示标记
if (bmarker) {
bmarker.setPosition(point)
} else {
bmarker = new BMap.Marker(point)
bmap.addOverlay(bmarker)
}
bmap.panTo(point)
bmap.setZoom(17)
// 反向地理编码
const geocoder = new BMap.Geocoder()
geocoder.getLocation(point, (result) => {
if (result) {
document.getElementById('statusPanel').innerHTML =
`<strong>${result.address}</strong>` +
`<br>WGS84: ${pos.coords.latitude.toFixed(5)}, ${pos.coords.longitude.toFixed(5)}` +
`<br>BD-09: ${bd.lat.toFixed(5)}, ${bd.lng.toFixed(5)}` +
`<br>精度: ±${pos.coords.accuracy.toFixed(0)}m`
}
})
} catch (err) {
document.getElementById('statusPanel').textContent = '定位失败: ' + err.message
}
}
// 页面加载完成
window.onload = () => {
initBaiduMap()
// 自动定位
setTimeout(locateOnBaiduMap, 1000)
}
</script>
</body>
</html>Google Maps SDK 集成
Google Maps 使用标准的 WGS84 坐标系，与浏览器 Geolocation API 直接兼容，无需坐标转换：
html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Google Maps + Geolocation 集成</title>
<style>
#gmap { width: 100%; height: 500px; }
.info-bar { padding: 12px; background: #e8f0fe; font-family: sans-serif; }
</style>
</head>
<body>
<div class="info-bar" id="infoBar">Loading Google Maps...</div>
<div id="gmap"></div>
<script>
let googleMap = null
let googleMarker = null
let accuracyCircle = null
function initGoogleMap() {
googleMap = new google.maps.Map(document.getElementById('gmap'), {
center: { lat: 39.9042, lng: 116.4074 },
zoom: 15,
mapTypeId: 'roadmap'
})
document.getElementById('infoBar').textContent = 'Google Maps ready. Click "Locate Me".'
}
async function locateOnGoogleMaps() {
try {
const position = await new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject, {
enableHighAccuracy: true,
timeout: 15000,
maximumAge: 0
})
})
const { latitude: lat, longitude: lng, accuracy: acc } = position.coords
// Google Maps 直接使用 WGS84 坐标，无需转换！
const pos = { lat, lng }
// 更新或创建标记
if (googleMarker) {
googleMarker.setPosition(pos)
} else {
googleMarker = new google.maps.Marker({
position: pos,
map: googleMap,
title: 'Your Location',
animation: google.maps.Animation.DROP,
icon: {
path: google.maps.SymbolPath.CIRCLE,
scale: 10,
fillColor: '#4285f4',
fillOpacity: 1,
strokeColor: '#ffffff',
strokeWeight: 3
}
})
}
// 精度圆圈
if (accuracyCircle) {
accuracyCircle.setCenter(pos)
accuracyCircle.setRadius(acc)
} else {
accuracyCircle = new google.maps.Circle({
center: pos,
radius: acc,
fillColor: '#4285f4',
fillOpacity: 0.15,
strokeColor: '#4285f4',
strokeOpacity: 0.3,
strokeWeight: 1,
map: googleMap
})
}
googleMap.panTo(pos)
googleMap.setZoom(17)
// 信息面板
document.getElementById('infoBar').innerHTML = `
<strong>📍 Location Found</strong> |
Lat: ${lat.toFixed(6)} |
Lng: ${lng.toFixed(6)} |
Accuracy: ±${Math.round(acc)}m
`
// 使用 Geocoding API 获取地址
const geocoder = new google.maps.Geocoder()
geocoder.geocode({ location: pos }, (results, status) => {
if (status === 'OK' && results[0]) {
document.getElementById('infoBar').innerHTML +=
`<br><small>Address: ${results[0].formatted_address}</small>`
}
})
} catch (error) {
const msgs = {
1: 'Permission denied by user',
2: 'Position unavailable',
3: 'Request timed out'
}
document.getElementById('infoBar').textContent =
'Error: ' + (msgs[error.code] || error.message)
}
}
// 添加定位按钮控件
function addLocateControl() {
const locateControlDiv = document.createElement('div')
locateControlDiv.style.backgroundColor = '#fff'
locateControlDiv.style.border = '2px solid #fff'
locateControlDiv.style.borderRadius = '3px'
locateControlDiv.style.boxShadow = '0 2px 6px rgba(0,0,0,.3)'
locateControlDiv.style.cursor = 'pointer'
locateControlDiv.style.textAlign = 'center'
locateControlDiv.title = 'Locate Me'
locateControlDiv.innerHTML = '📍 Locate'
locateControlDiv.addEventListener('click', locateOnGoogleMaps)
googleMap.controls[google.maps.ControlPosition.TOP_RIGHT].push(locateControlDiv)
}
</script>
<!-- Google Maps JS API -->
<script
src="https://maps.googleapis.com/maps/api/js?key=YOUR_GOOGLE_API_KEY&callback=initGoogleMap&libraries=geometry"
defer>
</script>
</body>
</html>三大坐标系速查表
| 坐标系 | 使用方 | 与 WGS84 偏移 | 转换方式 |
|---|---|---|---|
| WGS84 | 浏览器 Geolocation API、GPS 原始坐标、Google Maps | 基准（无偏移） | — |
| GCJ-02 | 高德地图、腾讯地图、天地图 | 有偏移（火星坐标） | WGS84 → GCJ-02 算法转换 |
| BD-09 | 百度地图 | 二次偏移 | GCJ-02 → BD-09 算法转换 |
隐私和安全
<h4>007-location-privacy.html</h4>html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>【7】位置隐私保护演示</title>
<!--
来源: HTML5基础知识/16-获取地理位置信息.md
知识点: 位置隐私保护、精度模糊化/网格化处理演示
-->
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
padding: 20px; background: linear-gradient(135deg, #141e30, #243b55);
color: #e0e0e0; min-height: 100vh;
}
.container { max-width: 1100px; margin: 0 auto; }
.header {
text-align: center; padding: 24px; background: linear-gradient(135deg, #6B73FF, #000DFF);
color: white; border-radius: 12px; margin-bottom: 24px;
}
.header h1 { font-size: 22px; margin-bottom: 6px; }
.header p { opacity: 0.9; font-size: 14px; }
.card {
background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1);
border-radius: 12px; padding: 24px; margin-bottom: 20px; backdrop-filter: blur(10px);
}
.card-title {
font-size: 15px; font-weight: 600; color: #a5b4fc;
border-left: 3px solid #6366f1; padding-left: 10px; margin-bottom: 16px;
}
.info-banner {
background: rgba(99,102,241,0.12); border: 1px solid rgba(99,102,241,0.25);
border-radius: 6px; padding: 12px 16px; font-size: 13px; line-height: 1.6;
color: #c7d2fe; margin-bottom: 16px;
}
/* 隐私策略卡片 */
.strategy-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; margin-bottom: 20px; }
.strat-card {
background: rgba(0,0,0,0.25); border: 1px solid rgba(255,255,255,0.08);
border-radius: 8px; padding: 16px; cursor: pointer; transition: all 0.2s;
}
.strat-card:hover { border-color: #6366f1; transform: translateY(-2px); }
.strat-card.active { border-color: #6366f1; background: rgba(99,102,241,0.1); }
.strat-icon { font-size: 24px; margin-bottom: 8px; }
.strat-name { font-size: 14px; font-weight: 700; margin-bottom: 4px; }
.strat-desc { font-size: 11px; color: #888; line-height: 1.5; }
.strat-param { margin-top: 10px; }
.strat-param label { font-size: 11px; color: #666; }
.strat-param input {
width: 70px; padding: 5px 8px; background: rgba(0,0,0,0.4); border: 1px solid #333;
color: #fff; border-radius: 4px; font-size: 12px; margin-left: 6px;
}
.controls { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 20px; }
.btn {
padding: 10px 22px; border: none; border-radius: 6px; cursor: pointer;
font-size: 13px; font-weight: 600; transition: all 0.2s;
}
.btn-primary { background: linear-gradient(135deg, #6366f1, #8b5cf6); color: white; }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 4px 16px rgba(99,102,241,0.3); }
/* 对比表格 */
.compare-table { width: 100%; border-collapse: collapse; font-size: 12px; margin-top: 16px; }
.compare-table th, .compare-table td {
padding: 10px 14px; text-align: left; border-bottom: 1px solid rgba(255,255,255,0.06);
}
.compare-table th { background: rgba(0,0,0,0.3); color: #a5b4fc; font-weight: 600; }
.compare-table code { background: rgba(99,102,241,0.15); padding: 2px 6px; border-radius: 3px; font-size: 11px; color: #a5b4fc; }
/* 结果展示 */
.result-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 16px; }
@media (max-width: 700px) { .result-grid { grid-template-columns: 1fr; } }
.result-panel {
background: rgba(0,0,0,0.3); border-radius: 8px; padding: 16px;
}
.result-header { font-size: 12px; font-weight: 700; color: #888; margin-bottom: 10px; text-transform: uppercase; letter-spacing: 1px; }
.coord-display {
font-family: monospace; font-size: 15px; color: #e0e0e0;
background: rgba(0,0,0,0.3); padding: 10px; border-radius: 4px;
margin-bottom: 6px;
}
.privacy-meter {
height: 6px; background: #333; border-radius: 3px; overflow: hidden; margin-top: 8px;
}
.privacy-fill { height: 100%; border-radius: 3px; transition: width 0.5s ease; }
.compat-note {
background: rgba(139,92,246,0.1); border: 1px solid rgba(139,92,246,0.25);
border-radius: 6px; padding: 10px 14px; font-size: 12px; color: #ddd6fe;
margin-top: 16px;
}
</style>
</head>
<body>
<div class="container">
<div class="header">
<h1>🔒 位置隐私保护演示</h1>
<p>精度模糊化 / 网格化处理 — 在提供位置服务的同时保护用户隐私</p>
</div>
<div class="card">
<div class="card-title">🛡️ 隐私保护策略</div>
<div class="info-banner">
💡 <strong>为什么需要位置隐私保护？</strong><br>
精确的位置信息可能被用于追踪用户的日常活动轨迹、推断家庭/工作地址等敏感信息。<br>
通过<strong>降低精度</strong>、<strong>网格化</strong>、<strong>添加随机噪声</strong>等方式，可以在保留位置服务功能的同时有效保护用户隐私。
</div>
<!-- 策略选择 -->
<div class="strategy-grid">
<div class="strat-card active" id="stratRaw" onclick="selectStrategy('raw')">
<div class="strat-icon">📍</div>
<div class="strat-name">原始坐标 (无保护)</div>
<div class="strat-desc">直接使用 API 返回的精确坐标，无任何隐私处理。</div>
</div>
<div class="strat-card" id="stratRound" onclick="selectStrategy('round')">
<div class="strat-icon">🔢</div>
<div class="strat-name">精度截断 (Rounding)</div>
<div class="strat-desc">将经纬度小数位数减少到指定位数。</div>
<div class="strat-param">
<label>保留小数位:</label>
<input type="number" id="roundDigits" value="3" min="0" max="7" />
</div>
</div>
<div class="strat-card" id="stratGrid" onclick="selectStrategy('grid')">
<div class="strat-icon">📐</div>
<div class="strat-name">网格化 (Grid Snapping)</div>
<div class="strat-desc">将坐标对齐到最近的网格交点。</div>
<div class="strat-param">
<label>网格大小 (°):</label>
<input type="number" id="gridSize" value="0.01" min="0.001" max="1" step="0.001" />
</div>
</div>
<div class="strat-card" id="stratNoise" onclick="selectStrategy('noise')">
<div class="strat-icon">🎲</div>
<div class="strat-name">添加随机噪声</div>
<div class="strat-desc">在坐标上叠加均匀分布的随机偏移。</div>
<div class="strat-param">
<label>噪声幅度 (°):</label>
<input type="number" id="noiseAmount" value="0.005" min="0.0001" max="0.1" step="0.001" />
</div>
</div>
<div class="strat-card" id="stratOffset" onclick="selectStrategy('offset')">
<div class="strat-icon">↗️</div>
<div class="strat-name">固定偏移 (Offset)</div>
<div class="strat-desc">向固定方向偏移固定距离。</div>
<div class="strat-param">
<label>偏移距离 (km):</label>
<input type="number" id="offsetKm" value="1" min="0.1" max="50" step="0.5" />
</div>
</div>
<div class="strat-card" id="stratFuzzy" onclick="selectStrategy('fuzzy')">
<div class="strat-icon">🌫️</div>
<div class="strat-name">模糊区域 (Fuzzy Region)</div>
<div class="strat-desc">只报告所在的城市/街区级别区域。</div>
</div>
</div>
<div class="controls">
<button class="btn btn-primary" onclick="applyPrivacy()">🔒 应用隐私策略并获取位置</button>
</div>
<!-- 结果对比 -->
<div class="result-grid">
<div class="result-panel">
<div class="result-header">📍 原始位置</div>
<div class="coord-display" id="rawCoord">--</div>
<div class="coord-display" style="font-size:12px;color:#888;" id="rawDetail">等待获取...</div>
<div style="font-size:11px;color:#ef4444;margin-top:4px;">⚠️ 隐私风险: 高</div>
<div class="privacy-meter"><div class="privacy-fill" id="rawPrivacy" style="width:5%;background:#ef4444;"></div></div>
</div>
<div class="result-panel">
<div class="result-header" id="protHeader">🔒 保护后位置</div>
<div class="coord-display" id="protCoord">--</div>
<div class="coord-display" style="font-size:12px;color:#888;" id="protDetail">选择策略后显示...</div>
<div style="font-size:11px;color:#22c55e;margin-top:4px;" id="protRisk">✅ 隐私风险: 低</div>
<div class="privacy-meter"><div class="privacy-fill" id="protPrivacy" style="width:95%;background:#22c55e;"></div></div>
</div>
</div>
<!-- 策略效果表 -->
<table class="compare-table">
<thead>
<tr>
<th>策略</th>
<th>原理</th>
<th>隐私保护程度</th>
<th>适用场景</th>
<th>位置偏差</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>原始坐标</code></td>
<td>不做任何处理</td>
<td style="color:#ef4444;">无</td>
<td>导航、精确配送</td>
<td>0m</td>
</tr>
<tr>
<td><code>精度截断</code></td>
<td>减少小数位数 (如 7→3 位)</td>
<td style="color:#f97316;">低~中</td>
<td>城市级天气、附近搜索</td>
<td>~100m ~ 100km</td>
</tr>
<tr>
<td><code>网格化</code></td>
<td>对齐到网格点</td>
<td style="color:#eab308;">中</td>
<td>热力图、区域统计</td>
<td>取决于网格大小</td>
</tr>
<tr>
<td><code>随机噪声</code></td>
<td>添加均匀/高斯噪声</td>
<td style="color:#84cc16;">中~高</td>
<td>广告定向、内容推荐</td>
<td>随机分布</td>
</tr>
<tr>
<td><code>模糊区域</code></td>
<td>仅报告区域名称</td>
<td style="color:#22c55e;">高</td>
<td>本地化内容、合规要求</td>
<td>数公里+</td>
</tr>
</tbody>
</table>
<div class="compat-note">
🔐 <strong>最佳实践：</strong>GDPR 和其他隐私法规要求最小化收集个人数据。
如果业务不需要精确位置，应始终采用适当的模糊策略。记录并告知用户你使用的隐私保护措施可以增加信任度。
</div>
</div>
</div>
<script>
let selectedStrategy = 'raw';
function selectStrategy(s) {
selectedStrategy = s;
document.querySelectorAll('.strat-card').forEach(c => c.classList.remove('active'));
document.getElementById('strat' + s.charAt(0).toUpperCase() + s.slice(1)).classList.add('active');
}
function applyPrivacy() {
if (!navigator.geolocation) { alert('浏览器不支持'); return; }
navigator.geolocation.getCurrentPosition(
function(pos) {
const c = pos.coords;
// 显示原始坐标
document.getElementById('rawCoord').textContent =
`${c.latitude.toFixed(7)}, ${c.longitude.toFixed(7)}`;
document.getElementById('rawDetail').textContent =
`精度: ±${c.accuracy.toFixed(1)}m | 海拔: ${c.altitude?.toFixed(1)||'--'}m`;
// 应用隐私策略
let protLat = c.latitude;
let protLng = c.longitude;
let strategyName = '';
let privacyPct = 5;
let riskColor = '#ef4444';
let riskText = '⚠️ 隐私风险: 高';
let detailText = '';
switch (selectedStrategy) {
case 'raw':
strategyName = '原始坐标 (无保护)';
privacyPct = 5;
break;
case 'round':
const digits = parseInt(document.getElementById('roundDigits').value) || 3;
const factor = Math.pow(10, digits);
protLat = Math.round(c.latitude * factor) / factor;
protLng = Math.round(c.longitude * factor) / factor;
strategyName = `精度截断 (${digits}位小数)`;
privacyPct = 20 + digits * 10;
detailText = `从 7 位截断至 ${digits} 位小数`;
break;
case 'grid':
const gs = parseFloat(document.getElementById('gridSize').value) || 0.01;
protLat = Math.round(c.latitude / gs) * gs;
protLng = Math.round(c.longitude / gs) * gs;
strategyName = `网格化 (${gs}°)`;
privacyPct = 60;
detailText = `对齐到 ${gs}° × ${gs}° 网格`;
break;
case 'noise':
const noise = parseFloat(document.getElementById('noiseAmount').value) || 0.005;
protLat = c.latitude + (Math.random() - 0.5) * 2 * noise;
protLng = c.longitude + (Math.random() - 0.5) * 2 * noise;
strategyName = `随机噪声 (±${noise}°)`;
privacyPct = 70;
detailText = `叠加均匀分布随机偏移`;
break;
case 'offset':
const km = parseFloat(document.getElementById('offsetKm') value) || 1;
// 约 1° 经度 ≈ 111km × cos(lat)
const degPerKm = 1 / 111;
protLat = c.latitude + km * degPerKm * 0.7;
protLng = c.longitude + km * degPerKm / Math.cos(c.latitude * Math.PI / 180);
strategyName = `固定偏移 (~${km}km)`;
privacyPct = 65;
detailText = `向东北方向偏移约 ${km}km`;
break;
case 'fuzzy':
// 只保留到 1° 级别 (约 100km)
protLat = Math.round(c.latitude);
protLng = Math.round(c.longitude * 10) / 10;
strategyName = '模糊区域 (城市级)';
privacyPct = 95;
detailText = '仅报告大致区域';
break;
}
// 显示保护后的坐标
document.getElementById('protCoord').textContent =
`${protLat.toFixed(7)}, ${protLng.toFixed(7)}`;
document.getElementById('protDetail').textContent =
`策略: ${strategyName}${detailText ? ' | ' + detailText : ''}`;
// 更新隐私条
document.getElementById('protPrivacy').style.width = `${privacyPct}%`;
const colors = ['#ef4444','#f97316','#eab308','#84cc16','#22c55e'];
const ci = Math.min(4, Math.floor(privacyPct / 25));
document.getElementById('protPrivacy').style.background = colors[ci];
document.getElementById('protRisk').textContent =
privacyPct > 70 ? '✅ 隐私风险: 低' :
privacyPct > 40 ? '⚠️ 隐私风险: 中' : '🔴 隐私风险: 高';
document.getElementById('protRisk').style.color = colors[ci];
console.log('原始:', c.latitude, c.longitude);
console.log('保护后:', protLat, protLng);
},
function(err) { alert(`错误: code=${err.code}`); },
{ enableHighAccuracy: true, timeout: 15000 }
);
}
</script>
</body>
</html>用户授权
Geolocation API 需要用户明确授权才能使用。浏览器会在首次请求位置信息时弹出授权提示。
重要提示：
- HTTPS 要求：现代浏览器（Chrome 50+）要求在使用 Geolocation API 时必须使用 HTTPS 协议（localhost 除外）
- 用户隐私：位置信息属于敏感数据，应明确告知用户使用目的
- 数据保护：不要将用户位置信息发送到不可信的服务器
权限状态检查
javascript
// 检查权限状态（需要 Permissions API 支持）
if (navigator.permissions) {
navigator.permissions.query({ name: "geolocation" }).then((result) => {
console.log("权限状态:", result.state)
if (result.state === "granted") {
// 已授权，可以直接获取位置
getLocation()
} else if (result.state === "prompt") {
// 需要用户授权
requestLocationPermission()
} else if (result.state === "denied") {
// 用户已拒绝，需要引导用户手动开启
showPermissionGuide()
}
// 监听权限变化
result.onchange = () => {
console.log("权限状态已更改:", result.state)
}
})
} else {
// 浏览器不支持 Permissions API，直接尝试获取位置
getLocation()
}安全建议
- 使用 HTTPS：确保网站使用 HTTPS 协议
- 明确告知：在请求位置前，向用户说明使用目的
- 最小化数据：只请求必要的位置精度
- 及时清理：使用完毕后及时停止监听，释放资源
- 数据加密：如果存储位置信息，应进行加密处理
位置隐私深度防护
随着全球隐私法规的日益严格（如欧盟 GDPR、美国 CCPA、中国《个人信息保护法》），位置数据的采集和使用必须遵循更高标准的隐私保护原则。
精度模糊化
降低位置精度是最直接有效的隐私保护手段之一。根据业务需求，将精确坐标模糊化到可接受的范围内：
javascript
/**
* 位置精度模糊化工具
* 通过网格化、随机偏移等方式降低位置精度
*/
class LocationObfuscator {
constructor(options = {}) {
this.options = {
gridPrecision: options.gridPrecision || 0.001, // 网格精度（约 111m/度）
randomOffset: options.randomOffset || 100, // 随机偏移范围（米）
minAccuracy: options.minAccuracy || 500, // 最小报告精度（米）
...options
}
}
/**
* 策略一：网格化（Grid-based Obfuscation）
* 将坐标对齐到最近的网格交叉点
*/
gridize(latitude, longitude) {
const precision = this.options.gridPrecision
const gridLat = Math.round(latitude / precision) * precision
const gridLng = Math.round(longitude / precision) * precision
return {
latitude: parseFloat(gridLat.toFixed(6)),
longitude: parseFloat(gridLng.toFixed(6)),
method: 'grid',
originalAccuracy: this.options.gridPrecision * 111000 / 2 // 近似米
}
}
/**
* 策略二：随机偏移（Random Offset）
* 在真实位置周围添加随机偏移
*/
randomize(latitude, longitude) {
const offsetMeters = this.options.randomOffset
// 1度纬度 ≈ 111km, 1度经度 ≈ 111km * cos(纬度)
const latOffset = (Math.random() - 0.5) * 2 * offsetMeters / 111000
const lngOffset = (Math.random() - 0.5) * 2 * offsetMeters / (111000 * Math.cos(latitude * Math.PI / 180))
return {
latitude: parseFloat((latitude + latOffset).toFixed(6)),
longitude: parseFloat((longitude + lngOffset).toFixed(6)),
method: 'random',
originalAccuracy: offsetMeters
}
}
/**
* 策略三：精度截断（Accuracy Floor）
* 强制将 accuracy 设为一个较大值，暗示位置不够精确
*/
floorAccuracy(position) {
const obfuscated = {
...position,
coords: {
...position.coords,
accuracy: Math.max(position.coords.accuracy, this.options.minAccuracy)
}
}
return obfuscated
}
/**
* 策略四：城市级别模糊（City-level）
* 仅保留城市级别的粗略位置
*/
toCityLevel(latitude, longitude) {
// 简化版：保留两位小数（约 1.1km 精度）
return {
latitude: parseFloat(latitude.toFixed(2)),
longitude: parseFloat(longitude.toFixed(2)),
method: 'city-level',
originalAccuracy: 1100
}
}
/**
* 综合模糊化处理
* 根据隐私等级选择合适的策略组合
*/
obfuscate(position, privacyLevel = 'medium') {
const strategies = {
low: () => this.floorAccuracy(position),
medium: () => {
const grid = this.gridize(position.coords.latitude, position.coords.longitude)
return {
...position,
coords: {
...position.coords,
latitude: grid.latitude,
longitude: grid.longitude,
accuracy: Math.max(position.coords.accuracy, grid.originalAccuracy)
}
}
},
high: () => {
const randomized = this.randomize(position.coords.latitude, position.coords.longitude)
return {
...position,
coords: {
...position.coords,
latitude: randomized.latitude,
longitude: randomized.longitude,
accuracy: this.options.minAccuracy
}
}
},
city: () => {
const city = this.toCityLevel(position.coords.latitude, position.coords.longitude)
return {
...position,
coords: {
...position.coords,
latitude: city.latitude,
longitude: city.longitude,
accuracy: city.originalAccuracy
}
}
}
}
return (strategies[privacyLevel] || strategies.medium)()
}
}精度模糊化使用示例
javascript
const obfuscator = new LocationObfuscator({
gridPrecision: 0.005, // 约 500m 网格
randomOffset: 200, // ±200m 随机偏移
minAccuracy: 500 // 最小精度 500m
})
// 原始位置（假设精度 10m）
const rawPosition = {
coords: { latitude: 39.984153, longitude: 116.307490, accuracy: 10 }
}
// 不同隐私等级的处理效果
console.log('原始位置:', rawPosition.coords)
console.log('低隐私保护:', obfuscator.obfuscate(rawPosition, 'low').coords)
// accuracy: 500 (仅提升 accuracy 值)
console.log('中等保护:', obfuscator.obfuscate(rawPosition, 'medium').coords)
// latitude/longitude 被网格化, accuracy ≥ 500m
console.log('高隐私保护:', obfuscator.obfuscate(rawPosition, 'high').coords)
// 坐标随机偏移, accuracy = 500m
console.log('城市级别:', obfuscator.obfuscate(rawPosition, 'city').coords)
// 仅保留 2 位小数, 约 1.1km 精度最小权限原则
只在真正需要的时候才请求位置权限，并且使用满足业务需求的最低精度配置：
javascript
/**
* 最小权限定位管理器
* 按需请求、按需释放、分级授权
*/
class MinimalLocationManager {
constructor() {
this.currentPurpose = null
this.activeWatchId = null
this.purposeLevels = {
weather: { // 天气查询：城市级别即可
enableHighAccuracy: false,
timeout: 5000,
maximumAge: 300000, // 5分钟缓存
privacyLevel: 'city'
},
nearby_search: { // 附近搜索：区县级
enableHighAccuracy: false,
timeout: 8000,
maximumAge: 120000,
privacyLevel: 'medium'
},
navigation: { // 导航：需要高精度
enableHighAccuracy: true,
timeout: 10000,
maximumAge: 0,
privacyLevel: 'low'
},
checkin: { // 打卡：中等精度
enableHighAccuracy: true,
timeout: 10000,
maximumAge: 0,
privacyLevel: 'medium'
}
}
}
/**
* 按用途获取位置
* @param {string} purpose - 用途标识
* @returns {Promise<Position>} 模糊化后的位置
*/
async getLocationForPurpose(purpose) {
const config = this.purposeLevels[purpose]
if (!config) {
throw new Error(`未知用途: ${purpose}`)
}
this.currentPurpose = purpose
console.log(`[Privacy] 请求位置权限, 用途: ${purpose}`)
// 先检查权限状态
if (navigator.permissions) {
const status = await navigator.permissions.query({ name: 'geolocation' })
if (status.state === 'denied') {
throw new Error('位置权限已被拒绝')
}
}
const position = await new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject, config)
})
// 根据隐私等级进行模糊化
const obfuscator = new LocationObfuscator()
return obfuscator.obfuscate(position, config.privacyLevel)
}
/**
* 用途结束后立即释放资源
*/
release(purpose) {
if (this.currentPurpose === purpose) {
if (this.activeWatchId !== null) {
navigator.geolocation.clearWatch(this.activeWatchId)
this.activeWatchId = null
}
this.currentPurpose = null
console.log(`[Privacy] 位置权限已释放, 用途: ${purpose}`)
}
}
}
// 使用示例
const locMgr = new MinimalLocationManager()
// 场景1：天气查询（最低权限）
try {
const weatherPos = await locMgr.getLocationForPurpose('weather')
fetchWeather(weatherPos.coords.latitude, weatherPos.coords.longitude)
locMgr.release('weather') // 立即释放
} catch (e) {
console.error('天气定位失败:', e)
// 降级：使用 IP 定位或默认城市
}
// 场景2：打卡签到（中等权限）
async function performCheckIn() {
try {
const checkinPos = await locMgr.getLocationForPurpose('checkin')
submitCheckIn(checkinPos.coords)
} finally {
locMgr.release('checkin')
}
}位置数据脱敏存储
当需要在客户端持久化存储位置数据时，必须进行脱敏处理：
javascript
/**
* 安全位置存储器
* 存储前脱敏、读取时还原元数据
*/
class SecureLocationStore {
constructor(storeName = 'secure_locations') {
this.storeName = storeName
}
/**
* 脱敏规则：
* 1. 坐标保留有限精度
* 2. 时间戳归整到分钟
* 3. 不存储 speed/heading 等动态信息
* 4. 添加数据过期时间
*/
_sanitize(position) {
return {
// 坐标保留4位小数（约11m精度）
lat: parseFloat(position.coords.latitude.toFixed(4)),
lng: parseFloat(position.coords.longitude.toFixed(4)),
// 归整到分钟
ts: Math.floor(position.timestamp / 60000) * 60000,
// 仅保留精度信息
acc: Math.round(position.coords.accuracy),
// 数据过期时间（7天后自动失效）
expireAt: Date.now() + 7 * 24 * 60 * 60 * 1000,
// 数据版本号（便于后续迁移/清洗）
schemaVersion: 1
}
}
async save(position) {
const sanitized = this._sanitize(position)
const db = await this._getDB()
await db.put(this.storeName, sanitized)
console.log('[SecureStore] 位置已安全存储')
}
async getAllValid() {
const db = await this._getDB()
const all = await db.getAll(this.storeName)
const now = Date.now()
// 过滤掉已过期的数据
return all.filter(item => item.expireAt > now)
}
async clearExpired() {
const db = await this._getDB()
const all = await db.getAll(this.storeName)
const now = Date.now()
const expired = all.filter(item => item.expireAt <= now)
for (const item of expired) {
await db.delete(this.storeName, item.ts)
}
console.log(`[SecureStore] 已清理 ${expired.length} 条过期数据`)
}
async clearAll() {
const db = await this._getDB()
await db.clear(this.storeName)
console.log('[SecureStore] 所有位置数据已清除')
}
async _getDB() {
// 使用 IndexedDB（如果可用），否则降级到 localStorage
if ('indexedDB' in window) {
return new Promise((resolve, reject) => {
const request = indexedDB.open('LocationSecureDB', 1)
request.onerror = () => reject(request.error)
request.onsuccess = () => resolve(request.result)
request.onupgradeneeded = (event) => {
const db = event.target.result
if (!db.objectStoreNames.contains(this.storeName)) {
db.createObjectStore(this.storeName, { keyPath: 'ts' })
}
}
}).then(db => db.transaction(this.storeName, 'readwrite').objectStore(this.storeName))
}
// localStorage 降级方案
return {
put: async (store, data) => {
const items = JSON.parse(localStorage.getItem(store) || '[]')
items.push(data)
localStorage.setItem(store, JSON.stringify(items))
},
getAll: async (store) => JSON.parse(localStorage.getItem(store) || '[]'),
delete: async (store, key) => {
const items = JSON.parse(localStorage.getItem(store) || '[]')
const filtered = items.filter(i => i.ts !== key)
localStorage.setItem(store, JSON.stringify(filtered))
},
clear: async (store) => localStorage.removeItem(store)
}
}
}GDPR / CCPA 合规要点
javascript
/**
* 隐私合规管理器
* 涵盖 GDPR（欧盟）、CCPA（加州）、PIPL（中国个人信息保护法）的核心要求
*/
class PrivacyComplianceManager {
constructor(options = {}) {
this.options = {
consentStorageKey: options.consentStorageKey || 'geo_consent_status',
retentionDays: options.retentionDays || 30, // 数据保留天数
requireExplicitConsent: options.requireExplicitConsent || true,
...options
}
}
/**
* 检查是否已获得用户同意
*/
hasConsent() {
const consent = localStorage.getItem(this.options.consentStorageKey)
if (!consent) return false
try {
const data = JSON.parse(consent)
// 检查同意是否仍在有效期内
if (data.expiresAt && data.expiresAt < Date.now()) {
this.revokeConsent()
return false
}
return data.granted === true
} catch {
return false
}
}
/**
* 记录用户同意
* @param {object} details - 同意详情（用途列表、是否可选等）
*/
grantConsent(details = {}) {
const consentRecord = {
granted: true,
purposes: details.purposes || ['essential'],
optional: details.optional || false,
grantedAt: new Date().toISOString(),
expiresAt: Date.now() + this.options.retentionDays * 24 * 60 * 60 * 1000,
version: '1.0',
userAgent: navigator.userAgent.substring(0, 100)
}
localStorage.setItem(
this.options.consentStorageKey,
JSON.stringify(consentRecord)
)
console.log('[Compliance] 用户同意已记录')
// GDPR 要求：用户有权撤回同意，需提供便捷入口
this._showWithdrawOption()
}
/**
* 撤销同意（GDPR Art. 7.3 / CCPA）
*/
revokeConsent() {
localStorage.setItem(this.options.consentStorageKey, JSON.stringify({
granted: false,
revokedAt: new Date().toISOString()
}))
console.log('[Compliance] 用户已撤销同意')
// 触发数据删除（GDPR Art. 17 被遗忘权）
this.triggerDataDeletion()
}
/**
* 生成隐私政策摘要
*/
generatePrivacyNotice() {
return {
// GDPR Art. 13: 信息透明度
dataController: '您的组织名称',
purposes: [
'提供基于位置的服务',
'改善用户体验',
'安全验证（可选）'
],
legalBasis: '用户明确同意 (GDPR Art. 6(1)(a))',
retentionPeriod: `${this.options.retentionDays} 天`,
rights: [
'访问权 (Access) - 查看收集的位置数据',
'更正权 (Rectification) - 修正不准确的数据',
'删除权 (Erasure) - 删除所有位置数据',
'限制处理权 (Restriction) - 限制数据处理',
'可携带权 (Portability) - 导出个人数据',
'反对权 (Object) - 反对特定处理活动'
],
// CCPA 特别条款
ccpaRights: [
'知晓权 - 了解收集了哪些信息',
'删除权 - 删除个人信息',
'退出销售权 - 退出个人信息出售',
'非歧视权 - 不得因行使权利而歧视'
],
contact: 'privacy@example.com'
}
}
/**
* 触发数据删除（被遗忘权）
*/
async triggerDataDeletion() {
const store = new SecureLocationStore()
await store.clearAll()
console.log('[Compliance] 位置数据已按用户请求删除')
// 同时通知服务端删除
try {
await fetch('/api/privacy/delete-my-data', {
method: 'POST',
credentials: 'include'
})
} catch (e) {
console.warn('[Compliance] 服务端删除通知失败:', e)
}
}
/**
* 导出用户数据（数据可携带权）
*/
async exportUserData() {
const store = new SecureLocationStore()
const data = await store.getAllValid()
const exportPackage = {
exportedAt: new Date().toISOString(),
recordType: 'location_data',
records: data,
recordCount: data.length,
format: 'JSON',
schema: 'SecureLocationStore_v1'
}
// 生成下载文件
const blob = new Blob([JSON.stringify(exportPackage, null, 2)], {
type: 'application/json'
})
const url = URL.createObjectURL(blob)
const a = document.createElement('a')
a.href = url
a.download = `my-location-data-${Date.now()}.json`
a.click()
URL.revokeObjectURL(url)
}
_showWithdrawOption() {
// 在页面底部显示"撤回同意"链接
if (!document.getElementById('privacy-withdraw')) {
const link = document.createElement('a')
link.id = 'privacy-withdraw'
link.href = '#'
link.textContent = '撤回位置权限同意'
link.style.cssText = 'font-size:12px;color:#999;display:block;text-align:center;padding:10px;'
link.onclick = (e) => {
e.preventDefault()
if (confirm('确定要撤回位置数据的处理同意吗？这将删除已存储的位置信息。')) {
this.revokeConsent()
link.textContent = '已撤回同意'
link.style.pointerEvents = 'none'
}
}
document.body.appendChild(link)
}
}
}
// 合规检查中间件
function withPrivacyCheck(locationAction) {
return async (...args) => {
const compliance = new PrivacyComplianceManager()
if (!compliance.hasConsent()) {
// 显示同意弹窗
showConsentDialog(async (granted) => {
if (granted) {
compliance.grantConsent()
await locationAction(...args)
} else {
console.info('[Compliance] 用户未同意，位置功能不可用')
}
})
return
}
// 同意有效，执行操作
return locationAction(...args)
}
}兼容性处理
对于不支持 Geolocation API 的浏览器，可以提供备用方案：
方案 1：IP 定位（精度较低）
javascript
async function getLocationByIP() {
try {
const response = await fetch("https://ipapi.co/json/")
const data = await response.json()
if (data.latitude && data.longitude) {
return {
latitude: data.latitude,
longitude: data.longitude,
accuracy: 10000, // IP定位精度较低，通常为几公里
source: "IP"
}
}
} catch (error) {
console.error("IP定位失败:", error)
}
return null
}
// 使用示例
async function getLocationWithFallback() {
if (navigator.geolocation) {
try {
const position = await new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject)
})
return {
latitude: position.coords.latitude,
longitude: position.coords.longitude,
accuracy: position.coords.accuracy,
source: "GPS"
}
} catch (error) {
console.warn("GPS定位失败，尝试IP定位")
return await getLocationByIP()
}
} else {
return await getLocationByIP()
}
}方案 2：使用第三方定位服务
javascript
// 使用高德地图定位服务（需要申请 API Key）
function getLocationByAMap() {
return new Promise((resolve, reject) => {
// 需要先加载高德地图 JS API
if (typeof AMap !== "undefined") {
const geolocation = new AMap.Geolocation({
enableHighAccuracy: true,
timeout: 10000
})
geolocation.getCurrentPosition((status, result) => {
if (status === "complete") {
resolve({
latitude: result.position.lat,
longitude: result.position.lng,
accuracy: result.accuracy,
source: "AMap"
})
} else {
reject(new Error(result.message))
}
})
} else {
reject(new Error("高德地图 API 未加载"))
}
})
}最佳实践
1. 错误处理
javascript
function getLocationSafely() {
return new Promise((resolve, reject) => {
if (!navigator.geolocation) {
reject(new Error("浏览器不支持地理定位"))
return
}
navigator.geolocation.getCurrentPosition(
resolve,
(error) => {
let message = "获取位置失败: "
switch (error.code) {
case error.PERMISSION_DENIED:
message += "用户拒绝了位置请求"
break
case error.POSITION_UNAVAILABLE:
message += "位置信息不可用"
break
case error.TIMEOUT:
message += "请求超时"
break
default:
message += "未知错误"
}
reject(new Error(message))
},
{
enableHighAccuracy: false,
timeout: 10000,
maximumAge: 60000
}
)
})
}2. 性能优化
javascript
// 使用缓存减少请求次数
let cachedPosition = null
let cacheTime = 0
const CACHE_DURATION = 60000 // 1分钟
function getCachedLocation() {
const now = Date.now()
// 如果缓存有效，直接返回
if (cachedPosition && now - cacheTime < CACHE_DURATION) {
return Promise.resolve(cachedPosition)
}
// 否则获取新位置
return getLocationSafely().then((position) => {
cachedPosition = position
cacheTime = now
return position
})
}3. 用户体验优化
javascript
// 显示加载状态
function getLocationWithUI() {
const loadingEl = document.getElementById("loading")
const errorEl = document.getElementById("error")
loadingEl.style.display = "block"
errorEl.style.display = "none"
getLocationSafely()
.then((position) => {
loadingEl.style.display = "none"
displayLocation(position)
})
.catch((error) => {
loadingEl.style.display = "none"
errorEl.style.display = "block"
errorEl.textContent = error.message
})
}4. 资源清理
javascript
// 确保在页面卸载时清理资源
window.addEventListener("beforeunload", () => {
if (watchId !== null) {
navigator.geolocation.clearWatch(watchId)
}
})
// 页面隐藏时暂停追踪
document.addEventListener("visibilitychange", () => {
if (document.hidden) {
// 页面隐藏，停止追踪
if (watchId !== null) {
navigator.geolocation.clearWatch(watchId)
watchId = null
}
} else {
// 页面显示，恢复追踪（如果需要）
// startWatching()
}
})5. 完整封装示例
javascript
class GeolocationService {
constructor(options = {}) {
this.options = {
enableHighAccuracy: options.enableHighAccuracy || false,
timeout: options.timeout || 10000,
maximumAge: options.maximumAge || 60000
}
this.watchId = null
this.cachedPosition = null
this.cacheTime = 0
}
async getCurrentPosition() {
if (!navigator.geolocation) {
throw new Error("浏览器不支持地理定位")
}
// 检查缓存
const now = Date.now()
if (this.cachedPosition && now - this.cacheTime < this.options.maximumAge) {
return this.cachedPosition
}
// 获取新位置
const position = await new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject, this.options)
})
// 更新缓存
this.cachedPosition = position
this.cacheTime = now
return position
}
watchPosition(onSuccess, onError) {
if (!navigator.geolocation) {
throw new Error("浏览器不支持地理定位")
}
this.watchId = navigator.geolocation.watchPosition(
(position) => {
this.cachedPosition = position
this.cacheTime = Date.now()
onSuccess(position)
},
onError,
this.options
)
return this.watchId
}
clearWatch() {
if (this.watchId !== null) {
navigator.geolocation.clearWatch(this.watchId)
this.watchId = null
}
}
clearCache() {
this.cachedPosition = null
this.cacheTime = 0
}
}
// 使用示例
const geoService = new GeolocationService({
enableHighAccuracy: true,
timeout: 10000,
maximumAge: 60000
})
try {
const position = await geoService.getCurrentPosition()
console.log("位置:", position.coords)
} catch (error) {
console.error("错误:", error)
}性能优化
1. 合理使用缓存
javascript
class LocationCache {
constructor(maxAge = 60000) {
this.cache = null
this.cacheTime = 0
this.maxAge = maxAge
}
get() {
if (this.cache && Date.now() - this.cacheTime < this.maxAge) {
return this.cache
}
return null
}
set(position) {
this.cache = position
this.cacheTime = Date.now()
}
clear() {
this.cache = null
this.cacheTime = 0
}
}
// 使用示例
const locationCache = new LocationCache(300000) // 5分钟缓存
async function getLocation() {
// 先尝试从缓存获取
const cached = locationCache.get()
if (cached) {
console.log("使用缓存位置")
return cached
}
// 获取新位置
const position = await new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject)
})
// 存入缓存
locationCache.set(position)
return position
}2. 智能精度控制
javascript
// 根据场景动态调整精度
function getOptimalOptions(scenario) {
const scenarios = {
// 快速定位，不要求高精度
quick: {
enableHighAccuracy: false,
timeout: 5000,
maximumAge: 300000 // 5分钟缓存
},
// 平衡模式
balanced: {
enableHighAccuracy: false,
timeout: 10000,
maximumAge: 60000
},
// 高精度定位
precise: {
enableHighAccuracy: true,
timeout: 15000,
maximumAge: 0
},
// 实时追踪
tracking: {
enableHighAccuracy: true,
timeout: 5000,
maximumAge: 0
}
}
return scenarios[scenario] || scenarios.balanced
}
// 使用示例
// 场景1：获取天气信息，快速定位即可
const weatherPosition = await getLocation(getOptimalOptions("quick"))
// 场景2：导航应用，需要高精度
const navPosition = await getLocation(getOptimalOptions("precise"))
// 场景3：实时位置追踪
const trackId = navigator.geolocation.watchPosition(
updateLocation,
handleError,
getOptimalOptions("tracking")
)3. 节流和防抖
javascript
// 对位置更新进行节流
function throttlePositionUpdate(callback, minInterval = 1000) {
let lastUpdate = 0
return (position) => {
const now = Date.now()
if (now - lastUpdate >= minInterval) {
lastUpdate = now
callback(position)
}
}
}
// 使用示例
const throttledUpdate = throttlePositionUpdate((position) => {
updateMap(position)
sendToServer(position)
}, 2000) // 最多每2秒更新一次
navigator.geolocation.watchPosition(throttledUpdate, handleError)4. 电池优化
javascript
// 根据电池状态调整定位策略
async function getBatteryOptimizedLocation() {
if ("getBattery" in navigator) {
const battery = await navigator.getBattery()
const options = {
enableHighAccuracy: battery.charging || battery.level > 0.5,
timeout: battery.level < 0.2 ? 5000 : 10000,
maximumAge: battery.level < 0.2 ? 300000 : 60000
}
console.log("电池状态:", {
level: battery.level,
charging: battery.charging,
options
})
return new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject, options)
})
}
// 不支持 Battery API，使用默认选项
return new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject)
})
}调试技巧
1. Chrome DevTools 模拟位置
Chrome 浏览器提供了位置模拟功能，方便开发测试：
步骤：
- 打开开发者工具（F12）
- 点击三个点菜单 → More tools → Sensors
- 在 "Geolocation" 部分：
- 选择预设位置（如 "Berlin"、"San Francisco"）
- 或自定义经纬度
- 或选择 "Location unavailable" 模拟错误
2. 其他浏览器模拟方法
| 浏览器 | 模拟方式 | 说明 |
|---|---|---|
| Chrome | DevTools → Sensors → Geolocation | 支持预设城市、自定义坐标、不可用模拟 |
| Firefox | about:config → geo.wifi.uri | 修改为本地 mock 服务 URL |
| Safari | Develop → Feature Responses → Location | 菜单式切换 |
| Edge | DevTools → Sensors（同 Chrome） | 基于 Chromium，与 Chrome 一致 |
| Android Chrome | DevTools → Remote Devices | 远程调试 + Sensors |
| iOS Simulator | Debug → Location → Custom Location | Xcode 模拟器内置 |
3. Firefox 模拟定位详细步骤
javascript
// Firefox 模拟定位方法
// 1. 地址栏输入 about:config
// 2. 搜索 geo.wifi.uri
// 3. 修改值为 data:application/json,{"location":{"lat":39.9042,"lng":116.4074,"accuracy":10}}
// 或者创建本地 Mock 服务
// 创建一个简单的位置 Mock 服务器（Node.js）
// mock-location-server.js
/*
const http = require('http');
const fs = require('fs');
const server = http.createServer((req, res) => {
// Mozilla Geolocation WiFi 服务格式
const mockData = {
location: {
lat: 39.9042,
lng: 116.4074,
accuracy: 10.0
},
accuracy: 10.0
};
res.writeHead(200, { 'Content-Type': 'application/json' });
res.end(JSON.stringify(mockData));
});
server.listen(18900, () => {
console.log('Mock location server running at http://localhost:18900');
console.log('Set Firefox geo.wfi.uri to: http://localhost:18900');
});
*/4. 控制台调试工具
javascript
// 地理位置调试工具
const GeoDebugger = {
// 检查API支持
checkSupport() {
console.group("Geolocation API 支持检查")
console.log("基础支持:", "geolocation" in navigator)
console.log("权限API:", "permissions" in navigator)
console.log("HTTPS:", location.protocol === "https:" || location.hostname === "localhost")
console.groupEnd()
},
// 检查权限状态
async checkPermission() {
if (navigator.permissions) {
const result = await navigator.permissions.query({ name: "geolocation" })
console.log("权限状态:", result.state)
return result.state
}
console.warn("Permissions API 不支持")
return null
},
// 测试定位
async testLocation() {
console.group("测试定位")
const startTime = Date.now()
try {
const position = await new Promise((resolve, reject) => {
navigator.geolocation.getCurrentPosition(resolve, reject, {
enableHighAccuracy: true,
timeout: 10000
})
})
const duration = Date.now() - startTime
console.log("✅ 定位成功")
console.log("耗时:", duration, "ms")
console.log("经度:", position.coords.longitude)
console.log("纬度:", position.coords.latitude)
console.log("精度:", position.coords.accuracy, "米")
console.log("时间戳:", new Date(position.timestamp).toLocaleString())
} catch (error) {
console.error("❌ 定位失败")
console.error("错误码:", error.code)
console.error("错误信息:", error.message)
}
console.groupEnd()
},
// 监控位置变化
monitorChanges(duration = 10000) {
console.log("开始监控位置变化，持续", duration / 1000, "秒")
const positions = []
const watchId = navigator.geolocation.watchPosition(
(position) => {
positions.push({
time: new Date().toLocaleTimeString(),
lat: position.coords.latitude,
lng: position.coords.longitude,
accuracy: position.coords.accuracy
})
console.log("位置更新:", positions[positions.length - 1])
},
(error) => console.error("监控错误:", error),
{ enableHighAccuracy: true, maximumAge: 0 }
)
setTimeout(() => {
navigator.geolocation.clearWatch(watchId)
console.log("监控结束，共记录", positions.length, "个位置点")
console.table(positions)
}, duration)
}
}
// 使用示例
GeoDebugger.checkSupport()
await GeoDebugger.checkPermission()
await GeoDebugger.testLocation()
GeoDebugger.monitorChanges(5000)5. 日志记录
javascript
// 详细的日志记录
class GeolocationLogger {
constructor() {
this.logs = []
}
log(type, data) {
const entry = {
timestamp: new Date().toISOString(),
type,
data
}
this.logs.push(entry)
console.log(`[GeoLog][${type}]`, data)
}
startWatching() {
this.log("watch_start", { time: new Date().toLocaleString() })
return navigator.geolocation.watchPosition(
(position) => this.log("position", {
lat: position.coords.latitude,
lng: position.coords.longitude,
accuracy: position.coords.accuracy,
timestamp: position.timestamp
}),
(error) => this.log("error", {
code: error.code,
message: error.message
})
)
}
getReport() {
return {
totalLogs: this.logs.length,
errors: this.logs.filter(l => l.type === "error").length,
positions: this.logs.filter(l => l.type === "position").length,
logs: this.logs
}
}
exportLogs() {
const data = JSON.stringify(this.logs, null, 2)
const blob = new Blob([data], { type: "application/json" })
const url = URL.createObjectURL(blob)
const a = document.createElement("a")
a.href = url
a.download = `geolocation-logs-${Date.now()}.json`
a.click()
}
}常见问题
Q1: 为什么在本地测试时定位不准确或失败？
原因：
- 本地 HTTP 环境下，部分浏览器限制定位功能
- 桌面浏览器通常使用 IP 定位，精度较低
- GPS 在室内信号弱
解决方案：
- 使用 HTTPS 或 localhost
- 使用 Chrome DevTools 模拟位置
- 在移动设备或外接 GPS 设备上测试
- 设置合理的
timeout和enableHighAccuracy
Q2: 为什么 Geolocation API 必须使用 HTTPS？
这是出于安全性考虑的设计决策：
| 安全威胁 | HTTP 环境 | HTTPS 环境 |
|---|---|---|
| 中间人攻击 (MITM) | 攻击者可拦截位置请求，伪造或窃取真实位置 | TLS 加密保护传输层安全 |
| 混合内容风险 | 非 HTTPS 页面的脚本可被注入恶意代码 | CSP 策略可有效防止 |
| 用户信任 | 用户无法确认谁在请求位置 | 锁定图标 + 域名验证增强信任 |
| 权限绑定 | 任何子资源都可能触发定位 | 权限与安全源（Origin）绑定 |
Chrome 50+（2016年起）的政策变更：
- 所有非安全的上下文（非 localhost、非 127.x.x.x、非 file://）中的
getCurrentPosition()/watchPosition()调用将在控制台产生警告 - 未来版本可能会完全阻止非安全上下文中的定位调用
开发阶段解决方案：
bash
# 使用 mkcert 生成本地可信证书
brew install mkcert
mkcert -install
mkcert localhost 127.0.0.1 ::1
# 然后在本地启动 HTTPS 服务器
npx serve -l tls --cert localhost+2.pem --key localhost+2-key.pem .Q3: watchPosition 电量消耗大如何优化？
watchPosition 持续运行时会显著增加设备电量消耗，尤其在移动端。以下是一套系统的优化方案：
javascript
/**
* 省电型位置追踪器
* 多层次电量优化策略
*/
class PowerSavingTracker {
constructor() {
this.watchId = null
this.currentStrategy = 'normal'
this.strategies = {
// 正常模式：平衡精度和电量
normal: {
enableHighAccuracy: false,
timeout: 10000,
maximumAge: 5000
},
// 省电模式：低频次、低精度
powerSave: {
enableHighAccuracy: false,
timeout: 30000,
maximumAge: 60000
},
// 高精度模式：仅在必要时启用
highPrecision: {
enableHighAccuracy: true,
timeout: 8000,
maximumAge: 0
}
}
}
async start() {
// 1. 检测电池状态，自适应策略
await this._adaptToBattery()
// 2. 检测网络状态，在线时才高精度
this._setupNetworkListener()
// 3. 启动追踪
this._applyStrategy()
}
async _adaptToBattery() {
if ('getBattery' in navigator) {
try {
const battery = await navigator.getBattery()
if (battery.level < 0.2 && !battery.charging) {
this.currentStrategy = 'powerSave'
console.log('[PowerSave] 低电量，启用省电模式')
} else if (battery.level > 0.8 && battery.charging) {
this.currentStrategy = 'highPrecision'
console.log('[PowerSave] 充电且电量充足，启用高精度模式')
} else {
this.currentStrategy = 'normal'
}
// 监听电池变化
battery.onlevelchange = () => this._adaptToBattery()
battery.onchargingchange = () => this._adaptToBattery()
} catch (e) {
console.warn('[PowerSave] Battery API 不可用')
}
}
}
_setupNetworkListener() {
// 离线时降低更新频率
window.addEventListener('online', () => {
console.log('[PowerSave] 网络恢复，恢复正常模式')
this.currentStrategy = 'normal'
this._restartWithNewStrategy()
})
window.addEventListener('offline', () => {
console.log('[PowerSave] 网络断开，切换到省电模式')
this.currentStrategy = 'powerSave'
this._restartWithNewStrategy()
})
}
_applyStrategy() {
const opts = this.strategies[this.currentStrategy]
this.watchId = navigator.geolocation.watchPosition(
(position) => {
// 收到位置后短暂休眠（进一步减少唤醒次数）
this._scheduleNextWake(opts.maximumAge || 10000)
},
(error) => console.error('定位错误:', error),
opts
)
console.log(`[PowerSave] 当前策略: ${this.currentStrategy}`, opts)
}
_restartWithNewStrategy() {
if (this.watchId !== null) {
navigator.geolocation.clearWatch(this.watchId)
}
this._applyStrategy()
}
_scheduleNextWake(delay) {
// 如果在省电模式，可以主动暂停一段时间再恢复
if (this.currentStrategy === 'powerSave' && this.watchId !== null) {
navigator.geolocation.clearWatch(this.watchId)
this.watchId = null
setTimeout(() => {
if (this.watchId === null) {
this._applyStrategy()
}
}, delay)
}
}
stop() {
if (this.watchId !== null) {
navigator.geolocation.clearWatch(this.watchId)
this.watchId = null
}
}
}电量优化要点总结：
| 优化维度 | 具体措施 | 预期效果 |
|---|---|---|
| 精度控制 | 非必要时不启用 enableHighAccuracy | 减少 60-80% 电量消耗 |
| 缓存利用 | 设置较大的 maximumAge 值 | 减少硬件唤醒频率 |
| 页面可见性 | 后台时停止或降级追踪 | 后台零消耗 |
| 节流处理 | 限制回调执行频率 | 减少 CPU/GPU 活动 |
| 电池感知 | 低电量时自动降级 | 延长续航 20-40% |
| 网络联动 | 离线时降低更新频率 | 避免无效耗电 |
Q4: 如何在各平台模拟定位进行测试？
除了 Chrome DevTools Sensors 面板，还有以下常用方法：
Android 实机测试：
bash
# 方法1: adb 模拟定位
adb emu geo fix <经度> <纬度> [<海拔>]
# 示例：模拟北京天安门位置
adb emu geo fix 116.4074 39.9042
# 方法2: 使用 telnet
telnet localhost 5554
geo fix 116.4074 39.9042iOS 模拟器测试：
swift
// 在 iOS 模拟器中：Features → Location → Custom Location...
// 或使用命令行：
xcrun simctl location booted set 39.9042 116.4074通用 Mock 方案（适用于自动化测试）：
javascript
/**
* Geolocation Mock 工具
* 用于单元测试和 CI/CD 环境
*/
class GeolocationMock {
static install(mockPositions = []) {
this.originalGeolocation = navigator.geolocation
this.mockIndex = 0
this.mockData = mockPositions
const self = this
navigator.geolocation = {
getCurrentPosition(success, error, options) {
if (self.mockData.length === 0) {
// 默认 mock 数据
self._resolveDefault(success)
return
}
const pos = self.mockData[self.mockIndex % self.mockData.length]
self.mockIndex++
// 模拟网络延迟
setTimeout(() => {
success(self._createPosition(pos))
}, pos.delay || 100)
},
watchPosition(success, error, options) {
let count = 0
const interval = setInterval(() => {
if (self.mockData.length > 0) {
const pos = self.mockData[count % self.mockData.length]
count++
success(self._createPosition(pos))
} else {
success(self._createPosition({
lat: 39.9042 + Math.random() * 0.001,
lng: 116.4074 + Math.random() * 0.001
}))
}
}, options?.maximumAge || 2000)
return setInterval(() => {}, 999999) // 返回假 watchId
},
clearWatch(id) {
clearInterval(id)
}
}
}
static uninstall() {
if (this.originalGeolocation) {
navigator.geolocation = this.originalGeolocation
}
}
static _createPosition(data) {
return {
coords: {
latitude: data.lat,
longitude: data.lng,
accuracy: data.accuracy || 10,
altitude: data.altitude || null,
altitudeAccuracy: data.altitudeAccuracy || null,
heading: data.heading || null,
speed: data.speed || null
},
timestamp: data.timestamp || Date.now()
}
}
static _resolveDefault(success) {
setTimeout(() => {
success(this._createPosition({
lat: 39.9042,
lng: 116.4074,
accuracy: 15
}))
}, 50)
}
}
// 单元测试中使用
describe('LocationFeature', () => {
beforeEach(() => {
GeolocationMock.install([
{ lat: 39.9042, lng: 116.4074, accuracy: 10 },
{ lat: 39.9052, lng: 116.4084, accuracy: 12 },
{ lat: 39.9062, lng: 116.4094, accuracy: 8 }
])
})
afterEach(() => {
GeolocationMock.uninstall()
})
it('should correctly process location updates', async () => {
// 测试逻辑...
})
})Q5: 用户拒绝授权后如何处理？
javascript
async function handleDeniedPermission() {
// 1. 友好提示
alert("位置权限被拒绝，部分功能可能受限")
// 2. 提供替代方案
const userChoice = confirm(
"是否要手动输入位置？" +
"\n点击'确定'手动输入" +
"\n点击'取消'使用默认位置"
)
if (userChoice) {
// 显示手动输入界面
showManualLocationInput()
} else {
// 使用默认位置（如北京）
useDefaultLocation({ lat: 39.9042, lng: 116.4074 })
}
// 3. 引导用户修改权限
if (confirm("是否查看如何重新启用位置权限？")) {
window.open("帮助文档URL")
}
}Q6: 如何在微信浏览器中获取位置？
javascript
// 微信浏览器定位
function getLocationInWechat() {
return new Promise((resolve, reject) => {
// 检查是否在微信环境
const isWechat = /MicroMessenger/i.test(navigator.userAgent)
if (!isWechat) {
// 非微信环境，使用标准 API
navigator.geolocation.getCurrentPosition(resolve, reject)
return
}
// 微信环境，使用微信 JSSDK
if (typeof wx === "undefined") {
reject(new Error("微信 JSSDK 未加载"))
return
}
wx.ready(() => {
wx.getLocation({
type: "gcj02", // 火星坐标系
success: (res) => {
resolve({
coords: {
latitude: res.latitude,
longitude: res.longitude,
accuracy: res.accuracy
},
timestamp: Date.now()
})
},
fail: (error) => {
reject(new Error(error.errMsg))
}
})
})
})
}Q7: 如何处理坐标系统差异？
javascript
// 坐标转换工具
const CoordinateConverter = {
// WGS84 转 GCJ-02（火星坐标）
wgs84ToGcj02(lng, lat) {
const dLat = this.transformLat(lng - 105.0, lat - 35.0)
const dLng = this.transformLng(lng - 105.0, lat - 35.0)
const radLat = (lat / 180.0) * Math.PI
let magic = Math.sin(radLat)
magic = 1 - 0.00669342162296594323 * magic * magic
const sqrtMagic = Math.sqrt(magic)
dLat = (dLat * 180.0) / ((6378245.0 * (1 - 0.00669342162296594323)) / (magic * sqrtMagic) * Math.PI)
dLng = (dLng * 180.0) / (6378245.0 / sqrtMagic * Math.cos(radLat) * Math.PI)
const mgLat = lat + dLat
const mgLng = lng + dLng
return { lat: mgLat, lng: mgLng }
},
transformLat(x, y) {
let ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x))
ret += (20.0 * Math.sin(6.0 * x * Math.PI) + 20.0 * Math.sin(2.0 * x * Math.PI)) * 2.0 / 3.0
ret += (20.0 * Math.sin(y * Math.PI) + 40.0 * Math.sin(y / 3.0 * Math.PI)) * 2.0 / 3.0
ret += (160.0 * Math.sin(y / 12.0 * Math.PI) + 320 * Math.sin(y * Math.PI / 30.0)) * 2.0 / 3.0
return ret
},
transformLng(x, y) {
let ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x))
ret += (20.0 * Math.sin(6.0 * x * Math.PI) + 20.0 * Math.sin(2.0 * x * Math.PI)) * 2.0 / 3.0
ret += (20.0 * Math.sin(x * Math.PI) + 40.0 * Math.sin(x / 3.0 * Math.PI)) * 2.0 / 3.0
ret += (150.0 * Math.sin(x / 12.0 * Math.PI) + 300.0 * Math.sin(x / 30.0 * Math.PI)) * 2.0 / 3.0
return ret
}
}
// 使用示例
navigator.geolocation.getCurrentPosition((position) => {
// 浏览器返回的是 WGS84 坐标
const wgs84 = {
lat: position.coords.latitude,
lng: position.coords.longitude
}
// 转换为 GCJ-02（适用于高德地图、腾讯地图）
const gcj02 = CoordinateConverter.wgs84ToGcj02(wgs84.lng, wgs84.lat)
console.log("WGS84 坐标:", wgs84)
console.log("GCJ-02 坐标:", gcj02)
})Q8: watchPosition 耗电严重怎么办？
javascript
// 智能定位管理器
class SmartLocationTracker {
constructor() {
this.watchId = null
this.isTracking = false
this.lastPosition = null
}
// 开始追踪（仅在页面可见时）
startTracking() {
if (this.isTracking) return
this.isTracking = true
this.watchId = navigator.geolocation.watchPosition(
(position) => {
this.lastPosition = position
this.onPositionUpdate(position)
},
(error) => this.onPositionError(error),
{
enableHighAccuracy: false, // 低精度模式省电
maximumAge: 5000,
timeout: 10000
}
)
}
// 停止追踪
stopTracking() {
if (this.watchId !== null) {
navigator.geolocation.clearWatch(this.watchId)
this.watchId = null
}
this.isTracking = false
}
// 页面可见性管理
setupVisibilityManager() {
document.addEventListener("visibilitychange", () => {
if (document.hidden) {
// 页面隐藏，停止追踪
this.stopTracking()
console.log("页面隐藏，停止追踪以节省电量")
} else {
// 页面显示，恢复追踪
this.startTracking()
console.log("页面显示，恢复追踪")
}
})
}
onPositionUpdate(position) {
console.log("位置更新:", position.coords)
}
onPositionError(error) {
console.error("定位错误:", error)
}
}
// 使用示例
const tracker = new SmartLocationTracker()
tracker.setupVisibilityManager()
tracker.startTracking()Q9: 如何在离线应用中使用地理定位？
javascript
// Service Worker 中缓存位置
// service-worker.js
self.addEventListener("message", async (event) => {
if (event.data.type === "CACHE_LOCATION") {
const cache = await caches.open("geolocation-cache")
cache.put(
"/last-known-location",
new Response(JSON.stringify(event.data.position))
)
}
})
// 主线程代码
async function saveLocationOffline(position) {
// 保存到 IndexedDB
const db = await openDB("GeoDB", 1, {
upgrade(db) {
db.createObjectStore("locations", { keyPath: "timestamp" })
}
})
await db.add("locations", {
timestamp: position.timestamp,
latitude: position.coords.latitude,
longitude: position.coords.longitude,
accuracy: position.coords.accuracy
})
}
async function getLastKnownLocation() {
try {
const db = await openDB("GeoDB", 1)
const locations = await db.getAll("locations")
return locations[locations.length - 1] // 返回最近的位置
} catch (error) {
console.error("获取缓存位置失败:", error)
return null
}
}
// 使用示例
navigator.geolocation.getCurrentPosition(
async (position) => {
// 保存到本地
await saveLocationOffline(position)
console.log("位置已保存到本地")
},
async (error) => {
console.error("定位失败，尝试使用缓存")
const cachedLocation = await getLastKnownLocation()
if (cachedLocation) {
console.log("使用缓存位置:", cachedLocation)
}
}
)Q10: 如何批量处理位置数据？
javascript
// 批量位置处理器
class BatchLocationProcessor {
constructor(batchSize = 10, flushInterval = 30000) {
this.batch = []
this.batchSize = batchSize
this.flushInterval = flushInterval
this.timer = null
}
add(position) {
this.batch.push({
latitude: position.coords.latitude,
longitude: position.coords.longitude,
accuracy: position.coords.accuracy,
timestamp: position.timestamp
})
if (this.batch.length >= this.batchSize) {
this.flush()
} else if (!this.timer) {
this.timer = setTimeout(() => this.flush(), this.flushInterval)
}
}
async flush() {
if (this.batch.length === 0) return
const dataToSend = [...this.batch]
this.batch = []
if (this.timer) {
clearTimeout(this.timer)
this.timer = null
}
try {
await this.sendToServer(dataToSend)
console.log(`成功发送 ${dataToSend.length} 个位置点`)
} catch (error) {
console.error("发送失败，数据将重新加入队列")
this.batch.unshift(...dataToSend)
}
}
async sendToServer(data) {
const response = await fetch("/api/locations/batch", {
method: "POST",
headers: { "Content-Type": "application/json" },
body: JSON.stringify({ locations: data })
})
if (!response.ok) {
throw new Error("服务器错误")
}
}
}
// 使用示例
const batchProcessor = new BatchLocationProcessor(10, 30000)
navigator.geolocation.watchPosition(
(position) => batchProcessor.add(position),
console.error,
{ enableHighAccuracy: true, maximumAge: 0 }
)最佳实践总结
1. 用户体验优先
- ✅ 在请求位置前说明使用目的
- ✅ 提供加载状态反馈
- ✅ 错误提示清晰友好
- ✅ 提供手动输入或降级方案
- ❌ 不要在页面加载时立即请求位置
- ❌ 不要频繁弹窗骚扰用户
2. 性能优化
- ✅ 合理使用缓存（
maximumAge） - ✅ 根据场景选择精度模式
- ✅ 及时清理
watchPosition - ✅ 使用节流控制更新频率
- ❌ 不要长时间保持高精度追踪
- ❌ 不要在后台持续监听位置
3. 隐私安全
- ✅ 使用 HTTPS
- ✅ 明确告知用户数据用途
- ✅ 最小化数据收集
- ✅ 加密传输位置数据
- ❌ 不要将精确位置发送到不可信服务器
- ❌ 不要永久存储精确位置信息
4. 兼容性处理
- ✅ 检测 API 支持情况
- ✅ 提供优雅降级方案
- ✅ 处理所有错误类型
- ✅ 兼容主流浏览器和设备
- ❌ 不要假设 API 总是可用
- ❌ 不要忽略错误处理
5. 代码质量
- ✅ 使用 Promise 封装
- ✅ 统一错误处理
- ✅ 添加日志记录
- ✅ 编写单元测试
- ❌ 不要使用魔法数字
- ❌ 不要深层嵌套回调
参考资料：
更新日志：
- 2026-06-12: 文档全面增强，新增 Mermaid 图表（4个）、Geolocation 高级应用章节、主流地图 SDK 集成、位置隐私深度防护、补充 FAQ 等内容
补充示例
<h4>006-location-accuracy-viz.html</h4>html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>【6】位置精度可视化</title>
<!--
来源: HTML5基础知识/16-获取地理位置信息.md
知识点: accuracy 属性精度半径圆圈显示定位精度范围
-->
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
padding: 20px; background: #0f0f1a; color: #d0d0d0;
min-height: 100vh;
}
.container { max-width: 1050px; margin: 0 auto; }
.header {
text-align: center; padding: 24px; background: linear-gradient(135deg, #00b09b, #96c93d);
color: white; border-radius: 12px; margin-bottom: 24px;
}
.header h1 { font-size: 22px; margin-bottom: 6px; }
.header p { opacity: 0.9; font-size: 14px; }
.card {
background: #161622; border: 1px solid #2a2a3e; border-radius: 10px;
padding: 24px; margin-bottom: 20px;
}
.card-title {
font-size: 15px; font-weight: 600; color: #69f0ae;
border-left: 3px solid #00b09b; padding-left: 10px; margin-bottom: 16px;
}
.info-banner {
background: rgba(0,176,155,0.1); border: 1px solid rgba(0,176,155,0.25);
border-radius: 6px; padding: 12px 16px; font-size: 13px; line-height: 1.6;
color: #81e6c9; margin-bottom: 16px;
}
.controls { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-bottom: 16px; }
.btn {
padding: 10px 22px; border: none; border-radius: 6px; cursor: pointer;
font-size: 13px; font-weight: 600; transition: all 0.2s;
}
.btn-green { background: #00b09b; color: white; }
.btn-green:hover { background: #009688; transform: translateY(-1px); }
.btn-green:disabled { opacity: 0.4; cursor: not-allowed; }
/* 主展示区 */
.viz-area {
display: grid; grid-template-columns: 1fr 280px; gap: 20px;
}
@media (max-width: 800px) { .viz-area { grid-template-columns: 1fr; } }
.canvas-container {
background: #0a0a14; border: 1px solid #222; border-radius: 10px;
overflow: hidden; position: relative;
}
canvas { display: block; width: 100%; height: 420px; }
.legend {
position: absolute; bottom: 12px; left: 12px;
background: rgba(0,0,0,0.75); backdrop-filter: blur(8px);
border-radius: 6px; padding: 10px 14px; font-size: 11px; color: #999;
}
.legend-item { display: flex; align-items: center; gap: 6px; margin-bottom: 4px; }
.legend-dot { width: 10px; height: 10px; border-radius: 50%; }
/* 数据面板 */
.data-panel { display: flex; flex-direction: column; gap: 12px; }
.data-card {
background: #0d0d17; border: 1px solid #222; border-radius: 8px;
padding: 14px;
}
.data-card-title { font-size: 11px; color: #666; text-transform: uppercase; letter-spacing: 1px; margin-bottom: 8px; }
.data-row { display: flex; justify-content: space-between; padding: 5px 0; font-size: 13px; }
.data-key { color: #888; }
.data-val { font-family: monospace; font-weight: 600; color: #69f0ae; }
/* 精度等级指示 */
.accuracy-bar {
height: 8px; background: #222; border-radius: 4px; overflow: hidden;
margin-top: 8px;
}
.accuracy-fill {
height: 100%; border-radius: 4px; transition: all 0.5s ease;
}
.accuracy-levels { display: flex; flex-direction: column; gap: 8px; margin-top: 12px; }
.acc-level {
display: flex; align-items: center; gap: 8px; font-size: 11px; color: #888;
}
.acc-dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; }
.log-box {
background: #0a0a12; border-radius: 6px; padding: 12px;
font-family: monospace; font-size: 11px; max-height: 140px;
overflow-y: auto; color: #555; line-height: 1.6; margin-top: 12px;
}
.log-ok { color: #69f0ae; }
.compat-note {
background: rgba(150,201,61,0.1); border: 1px solid rgba(150,201,61,0.25);
border-radius: 6px; padding: 10px 14px; font-size: 12px; color: #b2ff59;
margin-top: 16px;
}
</style>
</head>
<body>
<div class="container">
<div class="header">
<h1>🎯 位置精度可视化</h1>
<p>accuracy 半径圆圈显示定位精度范围 — 理解 GPS/Wi-Fi/IP 定位精度差异</p>
</div>
<div class="card">
<div class="card-title">📡 精度分析面板</div>
<div class="info-banner">
💡 <strong>coords.accuracy</strong> 表示以米为单位的精度半径值。<br>
• 该值表示真实位置有 68% 的概率落在以返回坐标为圆心、accuracy 为半径的圆内<br>
• GPS 高精度模式通常 < 10m；Wi-Fi 定位约 20-100m；IP 定位可达数公里<br>
• 圆圈越小 = 定位越精确
</div>
<div class="controls">
<button class="btn btn-green" id="getLocBtn" onclick="getLocation()">📍 获取位置并分析精度</button>
<label style="font-size:12px;color:#888;">对比模式:</label>
<button class="btn btn-green" style="background:#455a64;padding:8px 16px;font-size:12px;" onclick="showComparison()">🔬 显示不同精度等级对比</button>
</div>
<div class="viz-area">
<div class="canvas-container">
<canvas id="accCanvas"></canvas>
<div class="legend">
<div class="legend-item"><span class="legend-dot" style="background:#00b09b;"></span> 返回的坐标点 (最佳估计)</div>
<div class="legend-item"><span class="legend-dot" style="background:rgba(0,176,155,0.3);"></span> accuracy 精度范围 (68%置信)</div>
<div class="legend-item"><span class="legend-dot" style="background:rgba(0,176,155,0.1);"></span> 2× accuracy (95%置信)</div>
</div>
</div>
<div class="data-panel">
<div class="data-card">
<div class="data-card-title">定位结果</div>
<div class="data-row"><span class="data-key">纬度</span><span class="data-val" id="vLat">--</span></div>
<div class="data-row"><span class="data-key">经度</span><span class="data-val" id="vLng">--</span></div>
<div class="data-row"><span class="data-key">海拔</span><span class="data-val" id="vAlt">--</span></div>
</div>
<div class="data-card">
<div class="data-card-title">精度数据</div>
<div class="data-row"><span class="data-key">accuracy</span><span class="data-val" id="vAcc">-- m</span></div>
<div class="data-row"><span class="data-key">altAccuracy</span><span class="data-val" id="vAltAcc">--</span></div>
<div class="data-row"><span class="data-key">精度等级</span><span class="data-val" id="vLevel">-</span></div>
<div class="accuracy-bar"><div class="accuracy-fill" id="accBarFill" style="width:0%"></div></div>
</div>
<div class="data-card">
<div class="data-card-title">精度等级参考</div>
<div class="accuracy-levels">
<div class="acc-level"><span class="acc-dot" style="background:#4caf50;"></span>< 10m — GPS 高精度</div>
<div class="acc-level"><span class="acc-dot" style="background:#8bc34a;"></span>10-50m — Wi-Fi 定位</div>
<div class="acc-level"><span class="acc-dot" style="background:#ffc107;"></span>50-500m — 蜂窝基站</div>
<div class="acc-level"><span class="acc-dot" style="background:#ff9800;"></span>500m-5km — IP 定位</div>
<div class="acc-level"><span class="acc-dot" style="background:#f44336;"></span>> 5km — 极低精度</div>
</div>
</div>
<div class="log-box" id="logBox">
<div>[系统] 点击按钮获取位置...</div>
</div>
</div>
</div>
<div class="compat-note">
ℹ️ accuracy 值受多种因素影响：GPS 信号强度、Wi-Fi 扫描结果、蜂窝网络密度、室内/室外环境等。
开启 enableHighAccuracy 通常能获得更好的精度但消耗更多电量。
</div>
</div>
</div>
<script>
const canvas = document.getElementById('accCanvas');
const ctx = canvas.getContext('2d');
function resizeCanvas() {
canvas.width = canvas.parentElement.clientWidth;
canvas.height = 420;
}
window.addEventListener('resize', () => { resizeCanvas(); if (currentData) drawAccuracyViz(currentData); });
resizeCanvas();
let currentData = null;
function log(msg) {
const el = document.getElementById('logBox');
const div = document.createElement('div');
div.className = 'log-ok';
div.textContent = `[${new Date().toTimeString().substring(0,8)}] ${msg}`;
el.insertBefore(div, el.firstChild);
}
function getLevel(acc) {
if (acc < 10) return { name: '极高 (GPS)', color: '#4caf50', pct: 95 };
if (acc < 50) return { name: '高 (Wi-Fi)', color: '#8bc34a', pct: 75 };
if (acc < 500) return { name: '中等 (基站)', color: '#ffc107', pct: 50 };
if (acc < 5000) return { name: '低 (IP)', color: '#ff9800', pct: 25 };
return { name: '极低', color: '#f44336', pct: 10 };
}
function drawAccuracyViz(data) {
const w = canvas.width, h = canvas.height;
ctx.fillStyle = '#0a0a14';
ctx.fillRect(0, 0, w, h);
const cx = w / 2, cy = h / 2;
const acc = data.accuracy;
const level = getLevel(acc);
// 计算缩放：让 accuracy 圆合适当大小显示
// 最大显示 5000m 半径对应画布短边的 45%
const maxDisplayM = 5000;
const scale = Math.min(w, h) * 0.45 / maxDisplayM;
// 2x accuracy 圈 (95% 置信)
const r2 = Math.min(acc * 2 * scale, Math.min(w, h) * 0.47);
ctx.beginPath();
ctx.arc(cx, cy, r2, 0, Math.PI * 2);
ctx.fillStyle = 'rgba(0,176,155,0.05)';
ctx.fill();
ctx.strokeStyle = 'rgba(0,176,155,0.15)';
ctx.lineWidth = 1;
ctx.setLineDash([4, 4]);
ctx.stroke();
ctx.setLineDash([]);
// 1x accuracy 圈 (68% 置信)
const r1 = Math.min(acc * scale, Math.min(w, h) * 0.46);
ctx.beginPath();
ctx.arc(cx, cy, r1, 0, Math.PI * 2);
ctx.fillStyle = 'rgba(0,176,155,0.12)';
ctx.fill();
ctx.strokeStyle = level.color;
ctx.lineWidth = 2;
ctx.stroke();
// 刻度线
for (let i = 1; i <= 4; i++) {
const tr = r1 * (i / 4);
ctx.beginPath();
ctx.arc(cx, cy, tr, 0, Math.PI * 2);
ctx.strokeStyle = 'rgba(255,255,255,0.04)';
ctx.lineWidth = 1;
ctx.stroke();
}
// 中心点
ctx.beginPath();
ctx.arc(cx, cy, 8, 0, Math.PI * 2);
ctx.fillStyle = '#00b09b';
ctx.fill();
ctx.strokeStyle = 'white';
ctx.lineWidth = 2;
ctx.stroke();
// 十字准星
ctx.beginPath();
ctx.moveTo(cx - 20, cy); ctx.lineTo(cx + 20, cy);
ctx.moveTo(cx, cy - 20); ctx.lineTo(cx, cy + 20);
ctx.strokeStyle = 'rgba(0,176,155,0.4)';
ctx.lineWidth = 1;
ctx.stroke();
// 标注
ctx.font = 'bold 13px system-ui';
ctx.fillStyle = '#69f0ae';
ctx.textAlign = 'center';
ctx.fillText(`精度 ±${acc.toFixed(1)}m`, cx, cy - 28);
ctx.font = '11px monospace';
ctx.fillStyle = '#666';
ctx.fillText(`${level.name}`, cx, cy + 38);
ctx.fillText(`${data.lat.toFixed(5)}, ${data.lng.toFixed(5)}`, cx, cy + 54);
// 标注圆圈含义
ctx.font = '10px system-ui';
ctx.fillStyle = 'rgba(0,176,155,0.5)';
ctx.textAlign = 'left';
ctx.fillText(`内圈: 68% 置信区间 (±${acc.toFixed(0)}m)`, 14, h - 32);
ctx.fillText(`外圈: 95% 置信区间 (±${(acc*2).toFixed(0)}m)`, 14, h - 16);
// 比例尺
const barLen = 100; // pixels
const meterVal = barLen / scale;
ctx.fillStyle = '#444';
ctx.fillRect(w - 140, h - 30, barLen, 3);
ctx.fillStyle = '#888';
ctx.font = '10px system-ui';
ctx.textAlign = 'center';
ctx.fillText(meterVal > 1000 ? `${(meterVal/1000).toFixed(1)}km` : `${meterVal.toFixed(0)}m`, w - 90, h - 38);
}
function showComparison() {
currentData = {
lat: 39.9042, lng: 116.4074,
accuracy: 250, alt: 50, altAcc: 15
};
document.getElementById('vLat').textContent = '39.904200';
document.getElementById('vLng').textContent = '116.407400';
document.getElementById('vAlt').textContent = '50 m';
document.getElementById('vAcc').textContent = '250 m';
document.getElementById('vAltAcc').textContent = '±15 m';
const level = getLevel(250);
document.getElementById('vLevel').textContent = level.name;
document.getElementById('vLevel').style.color = level.color;
document.getElementById('accBarFill').style.width = `${level.pct}%`;
document.getElementById('accBarFill').style.background = level.color;
drawAccuracyViz(currentData);
log('显示对比: accuracy=250m (中等精度)');
}
function getLocation() {
if (!navigator.geolocation) {
alert('浏览器不支持 Geolocation'); return;
}
const btn = document.getElementById('getLocBtn');
btn.disabled = true;
navigator.geolocation.getCurrentPosition(
function(pos) {
const c = pos.coords;
currentData = {
lat: c.latitude, lng: c.longitude,
accuracy: c.accuracy,
alt: c.altitude, altAcc: c.altitudeAccuracy
};
document.getElementById('vLat').textContent = c.latitude.toFixed(7);
document.getElementById('vLng').textContent = c.longitude.toFixed(7);
document.getElementById('vAlt').textContent = c.altitude !== null ? `${c.altitude.toFixed(1)} m` : '--';
document.getElementById('vAcc').textContent = `${c.accuracy.toFixed(1)} m`;
document.getElementById('vAltAcc').textContent = c.altitudeAccuracy !== null ? `±${c.altitudeAccuracy.toFixed(1)} m` : '--';
const level = getLevel(c.accuracy);
document.getElementById('vLevel').textContent = level.name;
document.getElementById('vLevel').style.color = level.color;
document.getElementById('accBarFill').style.width = `${level.pct}%`;
document.getElementById('accBarFill').style.background = level.color;
drawAccuracyViz(currentData);
log(`精度: ±${c.accuracy.toFixed(1)}m → ${level.name}`);
btn.disabled = false;
},
function(err) {
log(`错误: code=${err.code}`);
btn.disabled = false;
},
{ enableHighAccuracy: true, timeout: 15000, maximumAge: 0 }
);
}
</script>
</body>
</html>html
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>【8】位置变化节流与防抖</title>
<!--
来源: HTML5基础知识/16-获取地理位置信息.md
知识点: 位置变化节流与防抖 — 避免 watchPosition 过度触发
-->
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
padding: 20px; background: #0f172a; color: #e2e8f0;
min-height: 100vh;
}
.container { max-width: 1050px; margin: 0 auto; }
.header {
text-align: center; padding: 24px; background: linear-gradient(135deg, #f97316, #ea580c);
color: white; border-radius: 12px; margin-bottom: 24px;
}
.header h1 { font-size: 22px; margin-bottom: 6px; }
.header p { opacity: 0.9; font-size: 14px; }
.card {
background: #1e293b; border: 1px solid #334155; border-radius: 10px;
padding: 24px; margin-bottom: 20px;
}
.card-title {
font-size: 15px; font-weight: 600; color: #fb923c;
border-left: 3px solid #f97316; padding-left: 10px; margin-bottom: 16px;
}
.info-banner {
background: rgba(249,115,22,0.1); border: 1px solid rgba(249,115,22,0.25);
border-radius: 6px; padding: 12px 16px; font-size: 13px; line-height: 1.6;
color: #fdba74; margin-bottom: 16px;
}
/* 模式对比 */
.mode-compare { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 20px; }
@media (max-width: 800px) { .mode-compare { grid-template-columns: 1fr; } }
.mode-panel {
background: #0f172a; border: 2px solid #334155; border-radius: 10px;
overflow: hidden; transition: border-color 0.2s;
}
.mode-panel.active { border-color: #f97316; }
.mode-header {
padding: 12px 16px; font-size: 13px; font-weight: 700; display: flex;
align-items: center; gap: 8px;
}
.mode-header.raw { background: rgba(239,68,68,0.1); color: #fca5a5; }
.mode-header.throttled { background: rgba(34,197,94,0.1); color: #86efac; }
.mode-body { padding: 16px; }
/* 触发计数器 */
.counter-display {
display: flex; align-items: baseline; gap: 4px; justify-content: center;
padding: 16px; background: rgba(0,0,0,0.25); border-radius: 8px; margin-bottom: 12px;
}
.counter-num { font-size: 42px; font-weight: 800; font-family: monospace; }
.counter-label { font-size: 13px; color: #64748b; }
.counter-num.high { color: #ef4444; }
.counter-num.low { color: #22c55e; }
/* 时间线 */
.timeline-bar {
height: 40px; background: #1e293b; border-radius: 6px; overflow: hidden;
position: relative; margin-bottom: 10px;
}
.timeline-event {
position: absolute; bottom: 0; width: 3px; border-radius: 2px 2px 0 0;
transition: height 0.15s ease;
}
.timeline-event.raw { background: #ef4444; }
.timeline-event.throttled { background: #22c55e; }
/* 统计行 */
.stats-mini { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
.stat-cell {
background: rgba(255,255,255,0.03); border-radius: 4px;
padding: 8px 10px; text-align: center; font-size: 11px;
}
.stat-cell .val { font-weight: 700; font-size: 15px; }
.stat-cell .lbl { color: #64748b; margin-top: 2px; }
/* 控制区 */
.controls { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-bottom: 20px; }
label { font-size: 13px; color: #94a3b8; }
input[type="number"] {
width: 70px; padding: 7px 10px; background: #0f172a; border: 1px solid #475569;
color: #fff; border-radius: 5px; font-size: 13px;
}
input:focus { outline: none; border-color: #f97316; }
.btn {
padding: 10px 22px; border: none; border-radius: 6px; cursor: pointer;
font-size: 13px; font-weight: 600; transition: all 0.2s;
}
.btn-orange { background: linear-gradient(135deg, #f97316, #ea580c); color: white; }
.btn-orange:hover { transform: translateY(-1px); }
.btn-orange:disabled { opacity: 0.4; cursor: not-allowed; }
.btn-red { background: #dc2626; color: white; }
.btn-red:hover { background: #b91c1c; }
/* 原理说明 */
.principle-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 16px; }
.principle-card {
background: rgba(0,0,0,0.2); border: 1px solid rgba(255,255,255,0.06);
border-radius: 8px; padding: 16px;
}
.principle-card h4 { font-size: 13px; margin-bottom: 8px; color: #fb923c; }
.principle-card pre {
background: #0f172a; padding: 10px; border-radius: 6px;
font-size: 11px; color: #94a3b8; overflow-x: auto; line-height: 1.5;
}
.principle-card p { font-size: 11px; color: #64748b; line-height: 1.5; margin-top: 8px; }
.compat-note {
background: rgba(34,197,94,0.08); border: 1px solid rgba(34,197,94,0.2);
border-radius: 6px; padding: 10px 14px; font-size: 12px; color: #86efac;
margin-top: 16px;
}
</style>
</head>
<body>
<div class="container">
<div class="header">
<h1>⏱️ 位置变化节流与防抖</h1>
<p>避免 watchPosition 过度触发 — 节流 (Throttle) vs 防抖 (Debounce) 对比演示</p>
</div>
<div class="card">
<div class="card-title">🎛️ 节流/防抖对比实验</div>
<div class="info-banner">
💡 <strong>问题：</strong><code>watchPosition()</code> 在移动设备上可能每秒触发多次回调，导致：<br>
• 频繁的 DOM 更新 → UI 卡顿<br>
• 大量的网络请求 → 浪费带宽和服务器资源<br>
• 不必要的计算 → 电量消耗<br>
💡 <strong>解决方案：</strong><strong>节流 (Throttle)</strong> 固定时间间隔执行；<strong>防抖 (Debounce)</strong> 停止变化后延迟执行。
</div>
<div class="controls">
<label>节流间隔 (ms):</label>
<input type="number" id="throttleMs" value="2000" min="200" step="200" />
<label>防抖延迟 (ms):</label>
<input type="number" id="debounceMs" value="3000" min="500" step="500" />
<button class="btn btn-orange" id="startBtn" onclick="startDemo()">▶ 启动对比监控</button>
<button class="btn btn-red" id="stopBtn" onclick="stopDemo()" disabled>⛹ 停止</button>
</div>
<div class="mode-compare">
<!-- 原始模式 -->
<div class="mode-panel active" id="panelRaw">
<div class="mode-header raw">⚡ 原始模式 (无节流)</div>
<div class="mode-body">
<div class="counter-display">
<span class="counter-num high" id="countRaw">0</span>
<span class="counter-label">次触发</span>
</div>
<div class="timeline-bar" id="timelineRaw"></div>
<div class="stats-mini">
<div class="stat-cell"><div class="val" id="rateRaw">-</div><div class="lbl">触发频率</div></div>
<div class="stat-cell"><div class="val" id="savedRaw">-</div><div class="lbl">节省调用</div></div>
</div>
</div>
</div>
<!-- 节流/防抖模式 -->
<div class="mode-panel" id="panelThrottled">
<div class="mode-header throttled">✅ 节流 + 防抖模式</div>
<div class="mode-body">
<div class="counter-display">
<span class="counter-num low" id="countThrottled">0</span>
<span class="counter-label">次有效调用</span>
</div>
<div class="timeline-bar" id="timelineThrottled"></div>
<div class="stats-mini">
<div class="stat-cell"><div class="val" id="rateThrottled">-</div><div class="lbl">实际频率</div></div>
<div class="stat-cell"><div class="val" id="savedThrottled">-</div><div class="lbl">节省比例</div></div>
</div>
</div>
</div>
</div>
<!-- 原理说明 -->
<div class="principle-cards">
<div class="principle-card">
<h4>📌 Throttle 节流</h4>
<pre>function throttle(fn, delay) {
let lastCall = 0;
return function(...args) {
const now = Date.now();
if (now - lastCall >= delay) {
lastCall = now;
fn.apply(this, args);
}
};
}</pre>
<p>✅ 保证至少每隔 N ms 执行一次。适合持续性的位置更新场景。</p>
</div>
<div class="principle-card">
<h4>📌 Debounce 防抖</h4>
<pre>function debounce(fn, delay) {
let timer = null;
return function(...args) {
clearTimeout(timer);
timer = setTimeout(() => {
fn.apply(this, args);
}, delay);
};
}</pre>
<p>✅ 等待停止变化 N ms 后才执行。适合"最终位置"确定后的操作。</p>
</div>
</div>
<div class="compat-note">
ℹ️ 此示例同时展示两种策略：原始 watchPosition 回调全部记录 + 经过节流/防抖处理后的有效调用。
实际项目中通常选择其中一种或组合使用。
</div>
</div>
</div>
<script>
let watchId = null;
let rawCount = 0;
let throttledCount = 0;
let startTime = null;
let timerInterval = null;
// 节流和防抖实现
let lastThrottleTime = 0;
let debounceTimer = null;
const throttleMsInput = document.getElementById('throttleMs');
const debounceMsInput = document.getElementById('debounceMs');
// ====== 时间线绘制 ======
function addTimelineEvent(containerId, type, timePercent) {
const container = document.getElementById(containerId);
const bar = container;
const w = bar.clientWidth || 400;
const div = document.createElement('div');
div.className = `timeline-event ${type}`;
const x = Math.min(timePercent * w, w - 4);
div.style.left = `${x}px`;
div.style.height = '20px';
bar.appendChild(div);
// 限制事件数量
if (bar.children.length > 60) {
bar.removeChild(bar.firstChild);
}
}
function clearTimelines() {
['timelineRaw', 'timelineThrottled'].forEach(id => {
document.getElementById(id).innerHTML = '';
});
}
// ====== 核心逻辑 ======
function startDemo() {
if (!navigator.geolocation) { alert('不支持 Geolocation'); return; }
clearTimelines();
rawCount = 0;
throttledCount = 0;
lastThrottleTime = 0;
startTime = performance.now();
document.getElementById('startBtn').disabled = true;
document.getElementById('stopBtn').disabled = false;
document.getElementById('countRaw').textContent = '0';
document.getElementById('countThrottled').textContent = '0';
// 计时器
timerInterval = setInterval(() => {
const elapsed = ((performance.now() - startTime) / 1000).toFixed(0);
// 更新频率
const rateRaw = elapsed > 0 ? (rawCount / elapsed).toFixed(1) : '-';
const rateThrot = elapsed > 0 ? (throttledCount / elapsed).toFixed(1) : '-';
document.getElementById('rateRaw').textContent = rateRaw ? rateRaw + '/s' : '-';
document.getElementById('rateThrottled').textContent = rateThrot ? rateThrot + '/s' : '-';
// 更新节省统计
if (rawCount > 0 && throttledCount >= 0) {
const savedPct = ((1 - throttledCount / Math.max(rawCount, 1)) * 100).toFixed(0);
document.getElementById('savedRaw').textContent = '-';
document.getElementById('savedThrottled').textContent = savedPct + '%';
}
}, 1000);
const throttleMs = parseInt(throttleMsInput.value) || 2000;
const debounceMs = parseInt(debounceMsInput.value) || 3000;
watchId = navigator.geolocation.watchPosition(
// ====== 原始回调 (无处理) ======
function(pos) {
rawCount++;
document.getElementById('countRaw').textContent = rawCount;
const elapsed = (performance.now() - startTime) / 1000;
// 归一化到 0-1 (显示最近 30 秒)
const pct = (elapsed % 30) / 30;
addTimelineEvent('timelineRaw', 'raw', pct);
// ====== 节流处理 ======
const now = Date.now();
if (now - lastThrottleTime >= throttleMs) {
lastThrottleTime = now;
handleThrottledPosition(pos);
} else {
// 防抖：重置计时器
clearTimeout(debounceTimer);
debounceTimer = setTimeout(() => {
handleThrottledPosition(pos);
}, debounceMs);
}
},
function(err) {
console.error('Geolocation error:', err.code);
},
{ enableHighAccuracy: true, timeout: 30000, maximumAge: 0 }
);
}
function handleThrottledPosition(pos) {
throttledCount++;
document.getElementById('countThrottled').textContent = throttledCount;
const elapsed = (performance.now() - startTime) / 1000;
const pct = (elapsed % 30) / 30;
addTimelineEvent('timelineThrottled', 'throttled', pct);
}
function stopDemo() {
if (watchId !== null) {
navigator.geolocation.clearWatch(watchId);
watchId = null;
}
if (timerInterval) { clearInterval(timerInterval); timerInterval = null; }
clearTimeout(debounceTimer);
document.getElementById('startBtn').disabled = false;
document.getElementById('stopBtn').disabled = true;
const elapsed = ((performance.now() - startTime) / 1000).toFixed(0);
console.log(`=== 结果 ===`);
console.log(`原始触发: ${rawCount} 次 (${(rawCount/Math.max(elapsed,1)).toFixed(1)}/s)`);
console.log(`节流后调用: ${throttledCount} 次 (${(throttledCount/Math.max(elapsed,1)).toFixed(1)}/s)`);
console.log(`节省: ${((1-throttledCount/Math.max(rawCount,1))*100).toFixed(0)}%`);
}
</script>
</body>
</html>