//Xamarin.Forms.ListViewDataSource
 public override void DraggingEnded(UIScrollView scrollView, bool willDecelerate)
 {
     //System.Diagnostics.Debug.WriteLine("ScrollDelegate.DraggingEnded: willDecelerate=[" + willDecelerate + "]");
     if (!willDecelerate)
     {
         _scrolling = false;
         if (Element?.ItemsSource != null)
         {
             Element?.OnScrolled(this, EventArgs.Empty);
         }
     }
     Source?.DraggingEnded(scrollView, willDecelerate);
 }
 public override void DecelerationEnded(UIScrollView scrollView)
 {
     //System.Diagnostics.Debug.WriteLine("ScrollDelegate DecelerationEnded");
     Device.StartTimer(TimeSpan.FromMilliseconds(200), () =>
     {
         _scrolling = false;
         if (Element?.ItemsSource != null)
         {
             Element?.OnScrolled(this, EventArgs.Empty);
         }
         return(false);
     });
 }