Silverlight缩放到指定要素

              // 等比例缩放
               double expandPercentage = 30;  //自定义
               double widthExpand = selectedFeatureExtent.Width *(expandPercentage / 100);
               double heightExpand = selectedFeatureExtent.Height *(expandPercentage / 100);

               ESRI.ArcGIS.Client.Geometry.Envelope displayExtent = newESRI.ArcGIS.Client.Geometry.Envelope(
               selectedFeatureExtent.XMin - (widthExpand / 2),
               selectedFeatureExtent.YMin - (heightExpand / 2),
               selectedFeatureExtent.XMax + (widthExpand / 2),
               selectedFeatureExtent.YMax + (heightExpand / 2));

#Silverlight