private void Button_Click(object sender, System.Windows.RoutedEventArgs e)
{
FeatureLayer layer = new FeatureLayer()
{
Url = "http://serverapps.esri.com/ArcGIS/rest/services/California/MapServer/8"
};
layer.OutFields.Add("*");
MyMap.Layers.Add(layer);
MyDataGrid.Map = MyMap;
MyDataGrid.GraphicsLayer = layer;
}