扩展一个OpenLayers.Map对象

/**扩展OpenLayers.Map，将地图图层加载等操作封装在本对象中。
 * 
 */
Vgs.WebMap=OpenLayers.Class(OpenLayers.Map,{
	initialize:function(div,options)
	{
		if(!options)options={};
			options['controls']=[];
		OpenLayers.Map.prototype.initialize.apply(this,[div,options]);

		var extent = new OpenLayers.Bounds(-180,-90,180,90);
		this.bounds=extent;
		this.units="degree";
		this.numZoomLevels=16;
		this.maxResolution=(re1>re2?re1:re2);
		this.maxExtent=extent;

		this.restrictedExtent=extent;
		this.div.oncontextmenu = function () { return false;};

		var markerlyr= new OpenLayers.Layer.Markers(AppConfig.markerLyrName,{
			displayInLayerSwitcher:false,
			isBaseLayer: false
		});
		this.addLayer(markerlyr);
	},
	/**根据数组创建一个图层
	 * 
	 * @param {} name 图层名称
	 * @param {} isBlyr 是否为基础图层
	 * @param {} visible 是否可见
	 * @param {} array 图层名称数组
	 * @param {} type 图层类型附加参数
	 * @return {}
	 */
	createALayer:function(name,isBlyr,visible,array,type)
	{
		if(!type||type.length<=0)type='o';
		var templyr =  new OpenLayers.Layer.WMS(
				name,"./map/wmsproxy.jsp?mtype="+type, 
	   			{layers :array,format : "image/png",transparent: "true"}
	   			,{isBaseLayer:isBlyr,visibility:visible}
		);
		return templyr;
	},
	CLASS_NAME:"Vgs.WebMap"
});