arcgis for silverlight calls the map service

Hi all,

My customer gives me three levels between 18 to 20. I refer to the sample code from google, but it doesn't display the map.

string url = "http://lqmap.linqu.gov.cn//newmap/tianditu/linqu/verctor/wmts?SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=verctor&STYLE=default&TILEMATRIXSET=Matrix_0&TILEMATRIX=" + level.ToString() + "&TileRow=" + row.ToString() + "&TileCol=" + col.ToString() + "&FORMAT=image/png";

        this.FullExtent = new
        ESRI.ArcGIS.Client.Geometry.Envelope(118.229752145124, 36.0666713776665, 118.826389346455, 36.6236108423721);
        {
            SpatialReference = new ESRI.ArcGIS.Client.Geometry.SpatialReference(4326);
        };
        this.SpatialReference = new ESRI.ArcGIS.Client.Geometry.SpatialReference(4326);
        this.TileInfo = new TileInfo()
        {
            Height = 256,
            Width = 256,
            Origin = new ESRI.ArcGIS.Client.Geometry.MapPoint(118.229752145124, 36.6236108423721)
            {
                SpatialReference = new ESRI.ArcGIS.Client.Geometry.SpatialReference(4326)
            },
            Lods = new Lod[3]
        };

        TileInfo.Lods[0] = new Lod() { Resolution = 0.0000026822090148926 };
        TileInfo.Lods[1] = new Lod() { Resolution = 0.0000013411045074463 };
        TileInfo.Lods[2] = new Lod() { Resolution = 0.0000006705522537232 };

        base.Initialize();

What I have missed? Can someone help me?

Thanks.