摘要:如果你自己的数据已经超过1万个,如何进行合理的显示?除了聚合marker外,还有一个办法。那就是,只显示可视区域内的标注。
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成品图:
工具描述:
移动地图时(或改变地图级别时),只显示可视区域内的标注。非可视区域内的标注都移除。
这样可以保持高效的系统性能。
另外,可视区域内的标注,请保持在200以内。各类浏览器方能高效地显示。
如果有超过300个marker,建议使用聚合marker类,请参考LIB:http://dev.baidu.com/wiki/map/index.php?title=MapLibrary
1、从数据库里读取信息
数据库里需要存储的信息至少为:经纬度point,标注图片icon。
读取后,创建点、标注。(注意:只是创建标注,并不添加到地图上。)
//创建10个点
var p1 = new BMap.Point(116.387452,39.947302);
var p2 = new BMap.Point(116.361581,39.961129);
var p3 = new BMap.Point(116.437901,39.960133);
var p4 = new BMap.Point(116.459748,39.919528);
var p5 = new BMap.Point(116.424247,39.939557);
var p6 = new BMap.Point(116.485188,39.974511);
var p7 = new BMap.Point(116.485188,39.974511);
var p8 = new BMap.Point(116.494243,39.930484);
var p9 = new BMap.Point(116.45328,39.884103);
var p0 = new BMap.Point(116.456011,39.844671);
//创建10张图标
var icon1 = new BMap.Icon("img/1.jpg", new BMap.Size(50,50));
var icon2 = new BMap.Icon("img/2.jpg", new BMap.Size(50,50));
var icon3 = new BMap.Icon("img/3.jpg", new BMap.Size(50,50));
var icon4 = new BMap.Icon("img/4.jpg", new BMap.Size(50,50));
var icon5 = new BMap.Icon("img/5.jpg", new BMap.Size(50,50));
var icon6 = new BMap.Icon("img/6.jpg", new BMap.Size(50,50));
var icon7 = new BMap.Icon("img/7.jpg", new BMap.Size(50,50));
var icon8 = new BMap.Icon("img/8.jpg", new BMap.Size(50,50));
var icon9 = new BMap.Icon("img/9.jpg", new BMap.Size(50,50));
var icon0 = new BMap.Icon("img/0.jpg", new BMap.Size(50,50));
//创建10个marker,但不添加到地图上
var m1 = new BMap.Marker(p1,{icon:icon1});
var m2 = new BMap.Marker(p2,{icon:icon2});
var m3 = new BMap.Marker(p3,{icon:icon3});
var m4 = new BMap.Marker(p4,{icon:icon4});
var m5 = new BMap.Marker(p5,{icon:icon5});
var m6 = new BMap.Marker(p6,{icon:icon6});
var m7 = new BMap.Marker(p7,{icon:icon7});
var m8 = new BMap.Marker(p8,{icon:icon8});
var m9 = new BMap.Marker(p9,{icon:icon9});
var m0 = new BMap.Marker(p0,{icon:icon0});
为了方便运算,用一个数组将标注集合起来:
//建立一个marker的数组
var markers = [m1,m2,m3,m4,m5,m6,m7,m8,m9,m0,m11,m12,m13,m14,m15,m16,m17,m18,m19,m10,m21,m22,m23,m24,m25,m26,m27,m28,m29,m20];
2、判断标注是否在可视区域内
利用几何运算的LIB可以轻松判断,标注是否在可视区域内。
几何运算LIB:http://dev.baidu.com/wiki/map/index.php?title=MapLibrary
判断标注如果在可视区域内,则添加到地图上;如果标注不在可视区域内,则删除它。
判断代码:
//显示可视区域内的标注
function addMymarkers(){
for(i=0;i
if(result == true) map.addOverlay(markers[i]);
else map.removeOverlay(markers[i]);
}
}
3、将可视区域内的标注添加到地图上
在图块加载完毕,地图中心点改变,和地图级别改变时,都需要进行一次添加/移除标注的操作。
//对地图级别变化、移动结束和图块加载完毕后,进行添加marker的操作
map.addEventListener("tilesloaded", addMymarkers);
map.addEventListener("zoomend", addMymarkers);
map.addEventListener("moveend", addMymarkers);
4、给标注的区域画一个框
为了方便观看,我用的是折线覆盖物,你也可以使用多边形覆盖物。
//添加一个矩形覆盖物
var polyline = new BMap.Polyline([
new BMap.Point(116.279655,40.020499),
new BMap.Point(116.260683,39.833259),
new BMap.Point(116.532043,39.830599),
new BMap.Point(116.526869,40.021383),
new BMap.Point(116.279655,40.020499)
], {strokeColor:"blue", strokeWeight:6, strokeOpacity:0.5});
map.addOverlay(polyline);
本例全部源代码:
DOCTYPE html>
<html>
<head>
<meta http-equiv&#61;"Content-Type" content&#61;"text/html; charset&#61;gb2312" />
<title>社交地图title>
<script type&#61;"text/Javascript" src&#61;"http://api.map.baidu.com/api?v&#61;1.2">script>
<script type&#61;"text/Javascript" src&#61;"http://api.map.baidu.com/library/GeoUtils/1.2/src/GeoUtils_min.js">script>
head>
<body>
<div style&#61;"width:520px;height:340px;border:1px solid gray" id&#61;"container">div>
<div style&#61;"width:200px;height:340px;border:1px solid gray" id&#61;"info">div>
<p id&#61;"info">p>
body>
html>
<script type&#61;"text/Javascript">
//创建地图
var map &#61; new BMap.Map("container");
map.centerAndZoom(new BMap.Point(116.387452,39.947302), 13);
//添加一个矩形覆盖物
var polyline &#61; new BMap.Polyline([
new BMap.Point(116.279655,40.020499),
new BMap.Point(116.260683,39.833259),
new BMap.Point(116.532043,39.830599),
new BMap.Point(116.526869,40.021383),
new BMap.Point(116.279655,40.020499)
], {strokeColor:"blue", strokeWeight:6, strokeOpacity:0.5});
map.addOverlay(polyline);
//显示可视区域内的标注
function addMymarkers(){
document.getElementById("info").innerHTML &#61; &#39;&#39;;
for(i&#61;0;i<markers.length;i&#43;&#43;){
var result &#61; BMapLib.GeoUtils.isPointInRect(markers[i].point, map.getBounds());
if(result &#61;&#61; true) map.addOverlay(markers[i]);
else map.removeOverlay(markers[i]);
document.getElementById("info").innerHTML &#43;&#61; &#39;&#39; &#43; markers[i].getIcon().imageUrl &#43;&#39;" />&#39;;
}
}
//对地图级别变化、移动结束和图块加载完毕后&#xff0c;进行添加marker的操作
map.addEventListener("tilesloaded", addMymarkers);
map.addEventListener("zoomend", addMymarkers);
map.addEventListener("moveend", addMymarkers);
//创建30个点
var p1 &#61; new BMap.Point(116.387452,39.947302);
var p2 &#61; new BMap.Point(116.361581,39.961129);
var p3 &#61; new BMap.Point(116.437901,39.960133);
var p4 &#61; new BMap.Point(116.459748,39.919528);
var p5 &#61; new BMap.Point(116.424247,39.939557);
var p6 &#61; new BMap.Point(116.485188,39.974511);
var p7 &#61; new BMap.Point(116.485188,39.974511);
var p8 &#61; new BMap.Point(116.494243,39.930484);
var p9 &#61; new BMap.Point(116.45328,39.884103);
var p0 &#61; new BMap.Point(116.456011,39.844671);
var p11 &#61; new BMap.Point(116.387165,39.850654);
var p12 &#61; new BMap.Point(116.461185,39.8975);
var p13 &#61; new BMap.Point(116.380122,39.87458);
var p14 &#61; new BMap.Point(116.354395,39.899825);
var p15 &#61; new BMap.Point(116.394495,39.887093);
var p16 &#61; new BMap.Point(116.30524,39.902482);
var p17 &#61; new BMap.Point(116.287992,39.937676);
var p18 &#61; new BMap.Point(116.277931,39.911116);
var p19 &#61; new BMap.Point(116.340166,39.929267);
var p10 &#61; new BMap.Point(116.290004,39.965885);
var p21 &#61; new BMap.Point(116.377535,39.966548);
var p22 &#61; new BMap.Point(116.423672,39.95239);
var p23 &#61; new BMap.Point(116.423672,39.95239);
var p24 &#61; new BMap.Point(116.300353,40.003146);
var p25 &#61; new BMap.Point(116.294172,39.982251);
var p26 &#61; new BMap.Point(116.313432,39.977497);
var p27 &#61; new BMap.Point(116.390183,39.983357);
var p28 &#61; new BMap.Point(116.390183,39.983357);
var p29 &#61; new BMap.Point(116.484469,39.943872);
var p20 &#61; new BMap.Point(116.509191,39.932586);
//创建30张图标
var icon1 &#61; new BMap.Icon("img/1.jpg", new BMap.Size(50,50));
var icon2 &#61; new BMap.Icon("img/2.jpg", new BMap.Size(50,50));
var icon3 &#61; new BMap.Icon("img/3.jpg", new BMap.Size(50,50));
var icon4 &#61; new BMap.Icon("img/4.jpg", new BMap.Size(50,50));
var icon5 &#61; new BMap.Icon("img/5.jpg", new BMap.Size(50,50));
var icon6 &#61; new BMap.Icon("img/6.jpg", new BMap.Size(50,50));
var icon7 &#61; new BMap.Icon("img/7.jpg", new BMap.Size(50,50));
var icon8 &#61; new BMap.Icon("img/8.jpg", new BMap.Size(50,50));
var icon9 &#61; new BMap.Icon("img/9.jpg", new BMap.Size(50,50));
var icon0 &#61; new BMap.Icon("img/0.jpg", new BMap.Size(50,50));
var icon11 &#61; new BMap.Icon("img/11.jpg", new BMap.Size(50,50));
var icon12 &#61; new BMap.Icon("img/12.jpg", new BMap.Size(50,50));
var icon13 &#61; new BMap.Icon("img/13.jpg", new BMap.Size(50,50));
var icon14 &#61; new BMap.Icon("img/14.jpg", new BMap.Size(50,50));
var icon15 &#61; new BMap.Icon("img/15.jpg", new BMap.Size(50,50));
var icon16 &#61; new BMap.Icon("img/16.jpg", new BMap.Size(50,50));
var icon17 &#61; new BMap.Icon("img/17.jpg", new BMap.Size(50,50));
var icon18 &#61; new BMap.Icon("img/18.jpg", new BMap.Size(50,50));
var icon19 &#61; new BMap.Icon("img/19.jpg", new BMap.Size(50,50));
var icon10 &#61; new BMap.Icon("img/10.jpg", new BMap.Size(50,50));
var icon21 &#61; new BMap.Icon("img/21.jpg", new BMap.Size(50,50));
var icon22 &#61; new BMap.Icon("img/22.jpg", new BMap.Size(50,50));
var icon23 &#61; new BMap.Icon("img/23.jpg", new BMap.Size(50,50));
var icon24 &#61; new BMap.Icon("img/24.jpg", new BMap.Size(50,50));
var icon25 &#61; new BMap.Icon("img/25.jpg", new BMap.Size(50,50));
var icon26 &#61; new BMap.Icon("img/26.jpg", new BMap.Size(50,50));
var icon27 &#61; new BMap.Icon("img/27.jpg", new BMap.Size(50,50));
var icon28 &#61; new BMap.Icon("img/28.jpg", new BMap.Size(50,50));
var icon29 &#61; new BMap.Icon("img/29.jpg", new BMap.Size(50,50));
var icon20 &#61; new BMap.Icon("img/20.jpg", new BMap.Size(50,50));
//创建30个marker&#xff0c;但不添加到地图上
var m1 &#61; new BMap.Marker(p1,{icon:icon1});
var m2 &#61; new BMap.Marker(p2,{icon:icon2});
var m3 &#61; new BMap.Marker(p3,{icon:icon3});
var m4 &#61; new BMap.Marker(p4,{icon:icon4});
var m5 &#61; new BMap.Marker(p5,{icon:icon5});
var m6 &#61; new BMap.Marker(p6,{icon:icon6});
var m7 &#61; new BMap.Marker(p7,{icon:icon7});
var m8 &#61; new BMap.Marker(p8,{icon:icon8});
var m9 &#61; new BMap.Marker(p9,{icon:icon9});
var m0 &#61; new BMap.Marker(p0,{icon:icon0});
var m11 &#61; new BMap.Marker(p11,{icon:icon11});
var m12 &#61; new BMap.Marker(p12,{icon:icon12});
var m13 &#61; new BMap.Marker(p13,{icon:icon13});
var m14 &#61; new BMap.Marker(p14,{icon:icon14});
var m15 &#61; new BMap.Marker(p15,{icon:icon15});
var m16 &#61; new BMap.Marker(p16,{icon:icon16});
var m17 &#61; new BMap.Marker(p17,{icon:icon17});
var m18 &#61; new BMap.Marker(p18,{icon:icon18});
var m19 &#61; new BMap.Marker(p19,{icon:icon19});
var m10 &#61; new BMap.Marker(p10,{icon:icon10});
var m21 &#61; new BMap.Marker(p21,{icon:icon21});
var m22 &#61; new BMap.Marker(p22,{icon:icon22});
var m23 &#61; new BMap.Marker(p23,{icon:icon23});
var m24 &#61; new BMap.Marker(p24,{icon:icon24});
var m25 &#61; new BMap.Marker(p25,{icon:icon25});
var m26 &#61; new BMap.Marker(p26,{icon:icon26});
var m27 &#61; new BMap.Marker(p27,{icon:icon27});
var m28 &#61; new BMap.Marker(p28,{icon:icon28});
var m29 &#61; new BMap.Marker(p29,{icon:icon29});
var m20 &#61; new BMap.Marker(p20,{icon:icon20});
//建立一个marker的数组
var markers &#61; [m1,m2,m3,m4,m5,m6,m7,m8,m9,m0,m11,m12,m13,m14,m15,m16,m17,m18,m19,m10,m21,m22,m23,m24,m25,m26,m27,m28,m29,m20];
script>
2012-02-07 更新代码&#xff1a;修改addMymarkers函数。
当可视区域内的标注大于10的时候&#xff0c;只显示10个标注。并在右侧显示&#xff0c;可视区域内共有多少用户。
部分源代码&#xff1a;
//显示可视区域内的标注
function addMymarkers(){
document.getElementById("info").innerHTML &#61; "小于10个用户";
var j &#61; 0;
for(i&#61;0;i
if(result &#61;&#61; true && j<10) {
map.addOverlay(markers[i]);
&#43;&#43;j;
}
else if(result &#61;&#61; true && j>&#61;10){
&#43;&#43;j;
document.getElementById("info").innerHTML &#61; "可视区域内的用户数&#xff1a;" &#43; j &#43; "";
map.removeOverlay(markers[i]);
}
else map.removeOverlay(markers[i]);
}
}