private void Slider_PointerPressed(object sender, Windows.UI.Xaml.Input.PointerRoutedEventArgs e)
 {
     if (SliderOnDrag != null)
     {
         SliderOnDrag.Invoke(this, new EventArgs());
     }
 }
 private void Thumb_DragStarted(object sender, DragStartedEventArgs e)
 {
     if (SliderOnDrag != null)
     {
         SliderOnDrag.Invoke(this, new EventArgs());
     }
 }