显示鼠标在地图上的坐标

<esri:Map x:Name="MyMap" WrapAround="True" MouseMove="MyMap_MouseMove">
<esri:ArcGISTiledMapServiceLayer ID="MyLayer"
Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer"/>
</esri:Map>

<Grid Width="355" Height="65" HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,15,15,0" >
<Rectangle Stroke="Gray"  RadiusX="10" RadiusY="10" Fill="#77919191" Margin="0,0,0,6" >
<Rectangle.Effect>
<DropShadowEffect/>
</Rectangle.Effect>
</Rectangle>
<Rectangle Fill="#FFFFFFFF" Stroke="DarkGray" RadiusX="5" RadiusY="5" Margin="10,10,10,15"  />
<StackPanel Canvas.Left="20" Canvas.Top="14" Margin="20,14,10,0">
<TextBlock x:Name="ScreenCoordsTextBlock"
HorizontalAlignment="Left" VerticalAlignment="Center" Text="Screen Coords: " TextWrapping="Wrap" FontWeight="Bold" />
<TextBlock x:Name="MapCoordsTextBlock"
HorizontalAlignment="Left" VerticalAlignment="Center" Text="Map Coords: " TextWrapping="Wrap" FontWeight="Bold" />
</StackPanel>
</Grid>

private void MyMap_MouseMove(object sender, System.Windows.Input.MouseEventArgs args)
{
if (MyMap.Extent != null)
{
System.Windows.Point screenPoint = args.GetPosition(MyMap);
ScreenCoordsTextBlock.Text = string.Format("Screen Coords: X = {0}, Y = {1}",
screenPoint.X, screenPoint.Y);

ESRI.ArcGIS.Client.Geometry.MapPoint mapPoint = MyMap.ScreenToMap(screenPoint);
if (MyMap.WrapAroundIsActive)
mapPoint = ESRI.ArcGIS.Client.Geometry.Geometry.NormalizeCentralMeridian(mapPoint) as ESRI.ArcGIS.Client.Geometry.MapPoint;
MapCoordsTextBlock.Text = string.Format("Map Coords: X = {0}, Y = {1}",
Math.Round(mapPoint.X, 4), Math.Round(mapPoint.Y, 4));
}
}