<!DOCTYPE html> <head> <meta charset="utf-8"> <title>HTML5 Geolocation距离跟踪器</title> </head> <body onload="loadDemo()"> <h1>HTML5 Geolocation距离跟踪器</h1> <p id="status">该浏览器不支持HTML5 Geolocation。</p> <h2>当前位置：</h2> <table border="1"> <tr> <td width="40" scope="col">纬度</th> <td width="114" id="latitude">?</td> </tr> <tr> <td>经度</td> <td id="longitude">?</td> </tr> <tr> <td>准确度</td> <td id="accuracy">?</td> </tr> </table> <h4 id="currDist">本次移动距离：0 千米</h4> <h4 id="totalDist">总计移动距离：0 千米</h4> <script type="text/javascript"> var totalDistance = 0.0; var lastLat; var lastLong; function toRadians(degree) { return this * Math.PI / 180; } function distance(latitude1, longitude1, latitude2, longitude2) { // R是地球半径（KM） var R = 6371; var deltaLatitude = toRadians(latitude2-latitude1); var deltaLongitude = toRadians(longitude2-longitude1); latitude1 = toRadians(latitude1); latitude2 = toRadians(latitude2); var a = Math.sin(deltaLatitude/2) * Math.sin(deltaLatitude/2) + Math.cos(latitude1) * Math.cos(latitude2) * Math.sin(deltaLongitude/2) * Math.sin(deltaLongitude/2); var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); var d = R * c; return d; } function updateStatus(message) { document.getElementById("status").innerHTML = message; } function loadDemo() { if(navigator.geolocation) { updateStatus("浏览器支持HTML5 Geolocation。"); navigator.geolocation.watchPosition(updateLocation, handleLocationError, {maximumAge:20000}); } } function updateLocation(position) { var latitude = position.coords.latitude; var longitude = position.coords.longitude; var accuracy = position.coords.accuracy; document.getElementById("latitude").innerHTML = latitude; document.getElementById("longitude").innerHTML = longitude; document.getElementById("accuracy").innerHTML = accuracy; // 如果accuracy的值太大，我们认为它不准确，不用它计算距离 if (accuracy >= 500) { updateStatus("这个数据太不靠谱，需要更准确的数据来计算本次移动距离。"); return; } // 计算移动距离 if ((lastLat != null) && (lastLong != null)) { var currentDistance = distance(latitude, longitude, lastLat, lastLong); document.getElementById("currDist").innerHTML = "本次移动距离：" + currentDistance.toFixed(4) + " 千米"; totalDistance += currentDistance; document.getElementById("totalDist").innerHTML = "总计移动距离：" + currentDistance.toFixed(4) + " 千米"; } lastLat = latitude; lastLong = longitude; updateStatus("计算移动距离成功。"); } function handleLocationError(error) { switch(error.code) { case 0: updateStatus("尝试获取您的位置信息时发生错误：" + error.message); break; case 1: updateStatus("用户拒绝了获取位置信息请求。"); break; case 2: updateStatus("浏览器无法获取您的位置信息：" + error.message); break; case 3: updateStatus("获取您位置信息超时。"); break; } } </script> </body> </html>