private void MyMap_MapGesture(object sender, Map.MapGestureEventArgs e)
{
if (e.Gesture == GestureType.Tap && MyMap.Extent != null && !_dispatcherTimer.IsEnabled)
{
_currentScreenPoint = e.GetPosition(MyMap);
_dispatcherTimer.Start();
}
else if (e.Gesture == GestureType.DoubleTap)
{
_dispatcherTimer.Stop();
}
}