使用百度地图API实现轨迹回放
最近项目需要实现路线的轨迹回放功能，苦于对百度api不熟，一时想不到用什么方法实现回放，看到了网上有人分享的一个很简单例子，一下子清晰很多，总结了下，根据这个就可以实现很复杂的回放功能啦。
调用百度地图API实现路线的轨迹回放功能其实很简单，只要搞懂以下几点即可：
1.需要用Polyline方法先绘制好路线图
2.用Marker添加标注点
3.关键一步，通过结合定时器，使用Marker创建的标注点实例的setPosition改变标注点位置，实现播放功能
代码分享，直接复制即可使用
<!DOCTYPE html> <html> <head> <meta name="viewport" content="initial-scale=1.0, user-scalable=no" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Track</title> <style type="text/css"> html{height:100%} body{height:100%;margin:0px;padding:0px} #controller{width:100%; border-bottom:3px outset; height:30px; filter:alpha(Opacity=100); -moz-opacity:1; opacity:1; z-index:10000; background-color:lightblue;} #container{height:100%} </style> <script type="text/javascript" src="http://api.map.baidu.com/api?v=1.5&ak=D2b4558ebed15e52558c6a766c35ee73"></script> <script type="text/javascript"> //获取所有点的坐标 var points = [ new BMap.Point(114.00100, 22.550000), new BMap.Point(114.00130, 22.550000), new BMap.Point(114.00160, 22.550000), new BMap.Point(114.00200, 22.550000), new BMap.Point(114.00300, 22.550500), new BMap.Point(114.00400, 22.550000), new BMap.Point(114.00500, 22.550000), new BMap.Point(114.00505, 22.549800), new BMap.Point(114.00510, 22.550000), new BMap.Point(114.00515, 22.550000), new BMap.Point(114.00525, 22.550400), new BMap.Point(114.00537, 22.549500) ]; var map; //百度地图对象 var car; //汽车图标 var label; //信息标签 var centerPoint; var timer; //定时器 var index = 0; //记录播放到第几个point var followChk, playBtn, pauseBtn, resetBtn; //几个控制按钮 function init() { followChk = document.getElementById("follow"); playBtn = document.getElementById("play"); pauseBtn = document.getElementById("pause"); resetBtn = document.getElementById("reset"); //初始化地图,选取第一个点为起始点 map = new BMap.Map("container"); map.centerAndZoom(points[0], 15); map.enableScrollWheelZoom(); map.addControl(new BMap.NavigationControl()); map.addControl(new BMap.ScaleControl()); map.addControl(new BMap.OverviewMapControl({isOpen: true})); //通过DrivingRoute获取一条路线的point var driving = new BMap.DrivingRoute(map); driving.search(new BMap.Point(114.00100, 22.550000), new BMap.Point(113.95100, 22.550000)); driving.setSearchCompleteCallback(function() { //得到路线上的所有point points = driving.getResults().getPlan(0).getRoute(0).getPath(); //画面移动到起点和终点的中间 centerPoint = new BMap.Point((points[0].lng + points[points.length - 1].lng) / 2, (points[0].lat + points[points.length - 1].lat) / 2); map.panTo(centerPoint); //连接所有点 map.addOverlay(new BMap.Polyline(points, {strokeColor: "black", strokeWeight: 5, strokeOpacity: 1})); //显示小车子 label = new BMap.Label("", {offset: new BMap.Size(-20, -20)}); car = new BMap.Marker(points[0]); car.setLabel(label); map.addOverlay(car); //点亮操作按钮 playBtn.disabled = false; resetBtn.disabled = false; }); } function play() { playBtn.disabled = true; pauseBtn.disabled = false; var point = points[index]; if(index > 0) { map.addOverlay(new BMap.Polyline([points[index - 1], point], {strokeColor: "red", strokeWeight: 1, strokeOpacity: 1})); } label.setContent("经度: " + point.lng + "<br>纬度: " + point.lat); car.setPosition(point); index++; if(followChk.checked) { map.panTo(point); } if(index < points.length) { timer = window.setTimeout("play(" + index + ")", 200); } else { playBtn.disabled = true; pauseBtn.disabled = true; map.panTo(point); } } function pause() { playBtn.disabled = false; pauseBtn.disabled = true; if(timer) { window.clearTimeout(timer); } } function reset() { followChk.checked = false; playBtn.disabled = false; pauseBtn.disabled = true; if(timer) { window.clearTimeout(timer); } index = 0; car.setPosition(points[0]); map.panTo(centerPoint); } </script> </head> <body onload="init();"> <div id="controller" align="center"> <input id="follow" type="checkbox"><span style="font-size:12px;">画面跟随</span></input> <input id="play" type="button" value="播放" onclick="play();" disabled /> <input id="pause" type="button" value="暂停" onclick="pause();" disabled /> <input id="reset" type="button" value="重置" onclick="reset()" disabled /> </div> <div id="container"></div> </body> </html>
