private void RadioButton_Click(object sender, System.Windows.RoutedEventArgs e)
{
OpenStreetMapLayer osmLayer = MyMap.Layers["OSMLayer"] as OpenStreetMapLayer;
string layerTypeTag = (string)((RadioButton)sender).Content;
OpenStreetMapLayer.MapStyle newLayerType = (OpenStreetMapLayer.MapStyle)System.Enum.Parse(typeof(OpenStreetMapLayer.MapStyle),
layerTypeTag, true);
osmLayer.Style = newLayerType;
}