ArcGIS for Silverlight API google地图操作

1.地图图层
  <esri:Map x:Name="mymap"  WrapAround="True" SnapToLevels="True" Extent="13026373.9205,4389217.2155,13039428.4582,4395595.7317" >
            <esri:Map.Layers >
                <GoogDitu:GoogletopographicLayer >
                </GoogDitu:GoogletopographicLayer>
                <esri:Graphicslayer ID="MyGraphicslayer"/>
            </esri:Map.Layers>
        </esri:Map>
   Extent表示地图的范围大小，数值是墨卡托数

2.google服务图层
using System; 
using System.Net; 
using System.Windows; 
using System.Windows.Controls; 
using System.Windows.Documents; 
using System.Windows.Ink; 
using System.Windows.Input; 
using System.Windows.Media; 
using System.Windows.Media.Animation; 
using System.Windows.Shapes; 
using ESRI.ArcGIS.Client; 
using ESRI.ArcGIS.Client.Geometry;
 
 public class GoogletopographicLayer: TiledMapServiceLayer 
    { 
        private const double cornerCoordinate = 20037508.3427892;
        private string _baseURL = "m@161000000";
 
        public override void Initialize() 
       { 
            ESRI.ArcGIS.Client.Projection.WebMercator mercator = new ESRI.ArcGIS.Client.Projection.WebMercator(); 
           this.FullExtent = new ESRI.ArcGIS.Client.Geometry.Envelope(-20037508.3427892,-20037508.3427892,20037508.3427892,20037508.3427892) 
            { 
                SpatialReference = new SpatialReference(102100) 
            }; 
           //图层的空间坐标系 
           this.SpatialReference = new SpatialReference(102100); 
           // 建立切片信息，每个切片大小256*256px，共16级. 
           this.TileInfo = new TileInfo() 
           { 
               Height = 256,Width = 256,Origin = new MapPoint(-cornerCoordinate,cornerCoordinate) { SpatialReference = new ESRI.ArcGIS.Client.Geometry.SpatialReference(102100) },Lods = new Lod[20] 
           }; 
           //为每级建立方案，每一级是前一级别的一半. 
           double resolution = cornerCoordinate * 2 / 256; 
           for (int i = 0; i < TileInfo.Lods.Length; i++) 
            { 
              TileInfo.Lods[i] = new Lod() { Resolution = resolution }; 
              resolution /= 2; 
           } 
            // 调用初始化函数 
           base.Initialize(); 
       } 
 
       public override string GetTileUrl(int level,int row,int col) 
       { 
           string url = "http://mt" + (col % 4) + ".google.cn/vt/lyrs=" + _baseURL + "&v=w2.114&hl=zh-CN&gl=cn&" + "x=" + col + "&" + "y=" + row + "&" + "z=" + level + "&s=galil"; 
            if (_baseURL == "s@92") 
          { 
                 url = "http://mt" + (col % 4) + ".google.cn/vt/lyrs=" + _baseURL + "&v=w2.114&hl=zh-CN&gl=cn&" + "x=" + col + "&" + "y=" + row + "&" + "z=" + level + "&s=galil"; //加载Google遥感图 
           } 
           if (_baseURL == "t@128") 
            { 
               url = "http://mt" + (col % 4) + ".google.cn/vt/lyrs=" + _baseURL + ",r@169000000&v=w2.114&hl=zh-CN&gl=cn&" + "x=" + col + "&" + "y=" + row + "&" + "z=" + level + "&s=galil";//加载Google地形图 
            } 
            if (_baseURL == "m@161000000") 
           { 
                url = "http://mt" + (col % 4) + ".google.cn/vt/lyrs=" + _baseURL + "&v=w2.114&hl=zh-CN&gl=cn&" + "x=" + col + "&" + "y=" + row + "&" + "z=" + level + "&s=galil"; //加载Google街道图 
            } 
           return string.Format(url); 
           //调用加载初始的Google街道地图 
           //string baseUrl = "http://mt2.google.cn/vt/v=w2.116&hl=zh-CN&gl=cn&x={0}&y={1}&z={2}&s=G"; 
           //return string.Format(baseUrl,col,row,level);
           //以上显示的Google地图类型，有三种，根据需要，可以修改变量_baseURL的初始值即可。
        } 

    }

3.地图的放大缩小

 mymap.Zoom(1.5)其中数值大于1是放大
 mymap.Zoom(0.5)数值小于1是缩小

3.地图的中心点改变
mymap.PanTo()这个方法里放的是墨卡托经纬度

4.改变地图点的图标
 Symbol = new PictureMarkerSymbol() { Source = new BitmapImage(new Uri("../Images/pr.png",UriKind.Relative)),Width = 20,Height = 17 }

5.给地图添加图标
  Graphicslayer graphicslayer = mymap.Layers["MyGraphicslayer"] as Graphicslayer;
  MyGraphic graphic = new MyGraphic()
                        {
                            Geometry = mercator.FromGeographic(new MapPoint(Convert.Todouble(item.Longitude),Convert.Todouble(item.Latitude))),Symbol = new PictureMarkerSymbol() { Source = new BitmapImage(new Uri("../Images/pr.png",Height = 17 },};
  graphicslayer.Graphics.Add(graphic);