百度地圖海量點清除（始終保留最新的點）
將海量點新增到地圖上
var points_Point = [];
var options_Point = {size: BMAP_POINT_SIZE_SMALL,
shape: BMAP_POINT_SHAPE_STAR,
color: '#d340c3'
};
var pointCollection_Point = new BMap.PointCollection(points_Point, options_Point);//初始化PointCollection
var limitN=0;
map.addOverlay(pointCollection_Point);
移除所有海量點 map.clearOverlays()，但是有時我們想重新整理最新的點，比如始終保持最新的N個點。可以控制point_Point[] 的資料。
下面是一段測試程式碼，可去除以前的點新增新的點 。
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<style type="text/css">
body, html,#allmap {width: 100%;height: 100%;overflow: hidden;margin:0;font-family:"微軟雅黑";}
</style>
<script type="text/javascript" src="http://api.map.baidu.com/api?v=2.0&ak=E06eb9d756d0eafc722effb355657b4c"></script>
<title>車輛執行軌跡測試</title>
<script src="http://c.cnzz.com/core.php"></script></head>
<body>
<div id="result">
<input type="button" value="確定" onclick="Test()"/>
</div>
<div id="allmap"></div>
</body>
</html>
<script type="text/javascript">
var startLong = 106.652024;
var startLat = 26.617221;
var endLong = 106.652024;
var endLat = 26.614221;
var startLongR = 106.652024;
var startLatR = 26.617221;
var endLongR = 106.652024;
var endLatR = 26.614221;
var linesPoints = null;
// 百度地圖API功能
var map = new BMap.Map("allmap"); // 建立Map例項
map.centerAndZoom(new BMap.Point(106.652024,26.617221), 15); // 初始化地圖,設定中心點座標和地圖級別
map.addControl(new BMap.MapTypeControl()); //新增地圖型別控制元件
map.setCurrentCity("貴陽"); // 設定地圖顯示的城市 此項是必須設定的
map.enableScrollWheelZoom(true); //開啟滑鼠滾輪縮放
var points_Point = [];
var options_Point = {
size: BMAP_POINT_SIZE_SMALL,
shape: BMAP_POINT_SHAPE_STAR,
color: '#d340c3'
};
var pointCollection_Point = new BMap.PointCollection(points_Point, options_Point);//初始化PointCollection
var limitN=0;
map.addOverlay(pointCollection_Point);
// setInterval(goWay,500);
var carMk;
var myIcon = new BMap.Icon("http://sandbox.runjs.cn/uploads/rs/101/wmbvrxnx/kache.png", new BMap.Size(37,25), {imageOffset: new BMap.Size(0, 0)});//卡車
function goWay(){
startLong = endLong;
startLat = endLat;
endLong = getRound(endLong);
endLat = getRound(endLat);
// drawIcon(startLong,startLat,endLong,endLat);
//drawRedLine();
var point = new BMap.Point(endLong,endLat);
points_Point.push(point);
limitN++;
}
function Test(){
for(var i=0;i<10;i++){
goWay();
}
var point=new BMap.Point(endLong,endLat);
points_Point[0]=point;
points_Point[1]=point;
points_Point[2]=point;
points_Point[3]=point;
points_Point[4]=point;
points_Point[5]=point;
points_Point[6]=point;
}
function getRound(temp){
var i = Math.round(Math.random()*9+1);
if(i%2==0){
return temp + i*0.0001;
}else{
return temp - i*0.0001;
}
}
function getRound1(temp){
var i = Math.round(Math.random()*9+1);
if(i%2==0){
return temp + i*0.0002;
}else{
return temp - i*0.0002;
}
}
function drawRedLine(){
startLongR = endLongR;
startLatR = endLatR;
endLongR = getRound1(endLongR);
endLatR = getRound1(endLatR);
var polyline1 = new BMap.Polyline([
new BMap.Point(startLongR,startLatR),//起始點的經緯度
new BMap.Point(endLongR,endLatR)//終止點的經緯度
], {strokeColor:"red",//設定顏色
strokeWeight:3, //寬度
strokeOpacity:1});//透明度
map.addOverlay(polyline1);
}
function drawIcon(startLong,startLat,endLong,endLat){
// if(carMk){
// map.removeOverlay(carMk);
// }
// carMk = new BMap.Marker(
// new BMap.Point(endLong,endLat),//起始點的經緯度
// {icon:myIcon});
// map.addOverlay(carMk);
drawGreenLine(startLong,startLat,endLong,endLat);
}
</script>
以上程式碼可以通過對points_point[] 對應位置賦值來清楚以前的點 並且保證留下最新的海量點。