概述：
在前面有篇文章提到了OL3中的多地图联动展示，在本节中讲述在OL2中实现多地图的联动展示。
效果：
实现思路：
在Ol2中，实现多地图的联动展示也是比较简单的。查看OL2中map的api，可知只要添加map的move事件即可。
实现代码如下：
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0">
<meta name="apple-mobile-web-app-capable" content="yes">
<title>OpenLayers MapQuest Demo</title>
<link rel="stylesheet" type="text/css" href="http://dev.openlayers.org/theme/default/style.css"/>
<style type="text/css">
html, body, .map{
padding:0;
margin:0;
height:100%;
}
.map{
width: 50%;
float: left;
box-shadow: 1px 1px 1px;
}
</style>
<script type="text/javascript" src="http://dev.openlayers.org/OpenLayers.js"></script>
<script type="text/javascript">
var map1, map2;
function init(){
function getBaseLayer(layername, layer){
return new OpenLayers.Layer.XYZ(
layername,
[
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}"
],
{
isBaseLayer: true,
displayInLayerSwitcher:true
}
);
};
function getAnnoLayer(layername, layer, visiable){
return new OpenLayers.Layer.XYZ(
layername,
[
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}",
"http://t0.tianditu.com/DataServer?T="+layer+"&X=${x}&Y=${y}&L=${z}"
],
{
isBaseLayer: false,
visibility:visiable,
displayInLayerSwitcher:false
}
);
};
var baseLayers = ["vec_c","img_c"];
var vecLayer = getBaseLayer("vec",baseLayers[0]);
var imgLayer = getBaseLayer("img",baseLayers[1]);
var vecAnno1 = getAnnoLayer("cva", "cva_c", true);
var vecAnno2 = getAnnoLayer("cva", "cva_c", true);
var mousepos2 = new OpenLayers.Layer.Markers("mousepos");
map1 = new OpenLayers.Map({
div: "map1",
projection: "EPSG:4326",
layers: [vecLayer, vecAnno1],
numZoomLevels:20,
center: [103.847, 36.0473],
zoom: 4
});
map2 = new OpenLayers.Map({
div: "map2",
projection: "EPSG:4326",
layers: [imgLayer, vecAnno2, mousepos2],
numZoomLevels:20,
center: [103.847, 36.0473],
zoom: 4
});
map1.events.register("move", map1, function(evt){
var extent = map1.getExtent();
map2.zoomToExtent(extent, true);
});
map1.events.register("mousemove", map1, function(evt){
mousepos2.clearMarkers();
var scrPt = evt.xy;
var mapPt = map1.getLonLatFromPixel(scrPt);
var marker = new OpenLayers.Marker(mapPt);
mousepos2.addMarker(marker);
});
}
</script>
</head>
<body onload="init()">
<div id="map1" class="map"></div>
<div id="map2" class="map"></div>
</body>
