百度地图只加载视野内的坐标点

功能说明：覆盖物多于300操作不流畅，只加载视野内的坐标点可改善加载速度尽可能多的加载覆盖物、坐标点；

如下是JS 脚本：

var map,info,bssw,bsne,cur_bssw,cur_bsne,lenboo=false;

function displayMap(){

var ids="";

var arrSon = document.getElementsByName("checkbox");

for(i=0;i<arrSon.length;i++) {

if(arrSon[i].checked)ids+=","+arrSon[i].value;

}

if(ids.length<1){

alert("请选择业务员！");

return;

}else if(ids.length<40){

lenboo=true;

}

var url = "<%=basePath %>terminal/gps!loadShopGps.action?ids="+ids.substring(1,ids.length);

asyncRequestCallback(function(data){

loadMaps(data.lineList,data.cur_gps);

},url);

}

function loadMaps(dtoList,cur_gps){

map = new BMap.Map("map_canvas");

info=cur_gps.split(",");

var centerpoint = new BMap.Point(info[1],info[0]);

map.centerAndZoom(centerpoint, 14);

map.enableScrollWheelZoom();

map.addControl(new BMap.NavigationControl());

map.addControl(new BMap.MapTypeControl({mapTypes:[BMAP_NORMAL_MAP,BMAP_HYBRID_MAP]}));

map.addControl(new BMap.ScaleControl());

map.addControl(new BMap.OverviewMapControl());

map.addEventListener("dragend", function(e){

cur_bssw=map.getBounds().getSouthWest();

cur_bsne=map.getBounds().getNorthEast();

if(cur_bssw.lng!=bssw.lng || cur_bssw.lat!=bssw.lat)loopDisplayMap(dtoList);

})

map.addEventListener("zoomend", function(){

cur_bssw=map.getBounds().getSouthWest();

cur_bsne=map.getBounds().getNorthEast();

if(cur_bssw.lng!=bssw.lng || cur_bssw.lat!=bssw.lat)loopDisplayMap(dtoList);

});

loopDisplayMap(dtoList)

}

function loopDisplayMap(dtoList){

map.clearOverlays();

var mk =new BMap.Marker(new BMap.Point(info[1],info[0]));

map.addOverlay(mk);

var opts ={150,height:40,title:"<b>公司名称：<b>"};

var iw = new BMap.InfoWindow("&nbsp;&nbsp;"+info[2],opts);

mk.addEventListener("mouseover",function(){

mk.openInfoWindow(iw,new BMap.Point(info[1],info[0]));

});

mk.addEventListener("mouseout",function(){

mk.closeInfoWindow(iw);

});

var icon1= new BMap.Icon("<%=basePath%>common/images/pin_little.png",new BMap.Size(10,13),{anchor:new BMap.Size(5,13)});

var icon2= new BMap.Icon("<%=basePath%>common/images/pin_red.png",new BMap.Size(18,25),{anchor:new BMap.Size(9,25)});

var icon3= new BMap.Icon("<%=basePath%>common/images/pin_yellow.png",new BMap.Size(18,25),{anchor:new BMap.Size(9,25)});

var icon4= new BMap.Icon("<%=basePath%>common/images/pin_green.png",new BMap.Size(18,25),{anchor:new BMap.Size(9,25)});

var list,arr,shop,polyline;

var bs= map.getBounds();

bssw = bs.getSouthWest();

bsne = bs.getNorthEast();

for(var i = 0; i < dtoList.length; i++){

list=dtoList[i].gpsShopList;

arr=new Array();

for(var j = 0; j < list.length; j++){

shop = list[j];

if(bssw.lng<shop.longitude && bssw.lat<shop.latitude && bsne.lng>shop.longitude && bsne.lat>shop.latitude){

addRedDot(shop,shop.state==-1?icon1:shop.state==0?icon2:shop.state==1?icon3:icon4,dtoList[i].lineName,dtoList[i].realName);

arr.push(new BMap.Point(shop.longitude,shop.latitude));

}

}

polyline = new BMap.Polyline(arr,{strokeColor:"blue", strokeWeight:1, strokeOpacity:1});

if(lenboo)map.addOverlay(polyline);

}

}

function addRedDot(shop,icon,lineName,realName){

var p1 = new BMap.Point(shop.longitude,shop.latitude);

var marker=new BMap.Marker(p1,{icon:icon,raiseOnDrag:true});

marker.addEventListener("click", function(e){

var opts ={250,height:98,title:"<b>"+realName+"</b>"};

    var addr="所属线路："+lineName+"<br/>门店名称："+shop.shopName+"<br/>详细地址："+shop.chinaAddress;  

    var infoWindow = new BMap.InfoWindow(addr, opts);  //创建信息窗口对象  

    marker.openInfoWindow(infoWindow);

});

map.addOverlay(marker);

}