ArcGIS for Flex中引入google map作底图

　　上篇文章到在ArcGIS View中引入google map，这里讲ArcGIS for Flex中引入google map作底图。

　　同样道理，以google map作底图，需要编写继承自TiledMapServiceLayer的帮助类MapOperate。

　　MapOperate类的代码如下：

package
{
    
    import com.esri.ags.SpatialReference;
    import com.esri.ags.geometry.Extent;
    import com.esri.ags.geometry.MapPoint;
    import com.esri.ags.layers.TiledMapServiceLayer;
    import com.esri.ags.layers.supportClasses.LOD;
    import com.esri.ags.layers.supportClasses.TileInfo;
    
    import flash.net.URLRequest;

    
    public class MapOperate extends TiledMapServiceLayer  
    {  
        private var _tileInfo:TileInfo=new TileInfo();  
        private var _baseURL:String="";  
        private var MapStyle:String="";
        
        public function MapOperate(vMapStyle:String)  
        {  
            this.MapStyle=vMapStyle;
            super();  
            buildTileInfo();  
            setLoaded(true);  
        
        }  

        override public function get fullExtent():Extent  
        {  
            return new Extent(-20037508.342787, -20037508.342787, 20037508.342787, 20037508.342787, new SpatialReference(102113)); 
        }  
        
        override public function get initialExtent():Extent  
        {  
            return new Extent(-20037508.342787, -20037508.342787, 20037508.342787, 20037508.342787, new SpatialReference(102113));
        }  
        
        override public function get spatialReference():SpatialReference  
        {  
            return new SpatialReference(102113);  
        }  
        
        override public function get tileInfo():com.esri.ags.layers.supportClasses.TileInfo  
        {  
            return _tileInfo;  
        }  
        
        //获取矢量地图  
        override protected function getTileURL(level:Number, row:Number, col:Number):URLRequest  
        {  
            var s:String = "Galileo".substring(0, ((3 * col + row) % 8));

            var    url:String ="";
            if (this.MapStyle == "Vector")
            {
                url = "http://mt" + (col % 4) + ".google.com/vt/lyrs=m@158000000&hl=zh-CN&gl=cn&" +
                    "x=" + col + "&" +
                    "y=" + row + "&" +
                    "z=" + level + "&" +
                    "s=" + s;
            }
                
            //获取地形图
            else if (this.MapStyle == "Terrain")
            {
                url = "http://mt" + (col % 4) + ".google.cn/vt/lyrs=t@131,r@227000000&hl=zh-CN&gl=cn&" +
                    //url = "http://mt"+(col%4)+".google.com/vt/lyrs=t@128,r@177000000&hl=zh-CN&gl=cn&" +                     
                    "x=" + col + "&" +
                    "y=" + row + "&" +
                    "z=" + level + "&" +
                    "s=" + s;
            }
            
            //获取影像地图
            else if (this.MapStyle == "Image")
            {
                url = "http://mt" + (col % 4) + ".google.com/vt/lyrs=s&hl=en&gl=en&" +
                    "x=" + col + "&" +
                    "y=" + row + "&" +
                    "z=" + level + "&" +
                    "s=" + s;
            }
                
            //获取道路等POI，和影像地图配合使用        
            else if (this.MapStyle == "POI")
            {
                url = "http://mt" + (col % 4) + ".google.com/vt/imgtp=png32&lyrs=h@169000000&hl=zh-CN&gl=cn&" +
                    "x=" + col + "&" +
                    "y=" + row + "&" +
                    "z=" + level + "&" +
                    "s=" + s;
            }
            return new URLRequest(url);  
        }  
        public function set url(vals:String):void  
        {
            this._baseURL = vals;  
        }
        private function buildTileInfo():void  
        {  
            _tileInfo.height=256;  
            _tileInfo.width=256;  
            _tileInfo.origin=new MapPoint(-20037508.342787, 20037508.342787);
            _tileInfo.spatialReference=new SpatialReference(102113);  
            _tileInfo.lods = [  
                new LOD(0, 156543.033928, 591657527.591555),  
                new LOD(1, 78271.5169639999, 295828763.795777),  
                new LOD(2, 39135.7584820001, 147914381.897889),  
                new LOD(3, 19567.8792409999, 73957190.948944),  
                new LOD(4, 9783.93962049996, 36978595.474472),  
                new LOD(5, 4891.96981024998, 18489297.737236),  
                new LOD(6, 2445.98490512499, 9244648.868618),  
                new LOD(7, 1222.99245256249, 4622324.434309),  
                new LOD(8, 611.49622628138, 2311162.217155),  
                new LOD(9, 305.748113140558, 1155581.108577),  
                new LOD(10, 152.874056570411, 577790.554289),  
                new LOD(11, 76.4370282850732, 288895.277144),  
                new LOD(12, 38.2185141425366, 144447.638572),  
                new LOD(13, 19.1092570712683, 72223.819286),  
                new LOD(14, 9.55462853563415, 36111.909643),  
                new LOD(15, 4.77731426794937, 18055.954822),  
                new LOD(16, 2.38865713397468, 9027.977411),  
                new LOD(17, 1.19432856685505, 4513.988705),  
                new LOD(18, 0.597164283559817, 2256.994353),  
                new LOD(19, 0.298582141647617, 1128.497176)  
            ];  
        } 
        
        public function lon2Mercator(px:int):int
        {
            var x:int = px * 20037508.34 / 180;
            return x;
        }
        
        public    function lat2Mercator(py:int):int
        {
            var y:int;
            y = Math.log(Math.tan((90 + py) * Math.PI / 360)) / (Math.PI / 180);
            y = y * 20037508.34 / 180;
            return y;
        }
    }  
}

　　

　　下面是引入代码：

//加载Google图层
var googleLayer:MapOperate = new MapOperate("Image");
myMap.addLayer(googleLayer);

　　运行效果：