public override void TouchesEnded(NSSet touches, UIEvent evt)
 {
     if (!Dragging)
     {
         NextResponder.TouchesEnded(touches, evt);
     }
     else
     {
         base.TouchesEnded(touches, evt);
     }
 }
 public override void RightMouseDown(NSEvent theEvent)
 {
     NextResponder.RightMouseDown(theEvent);
 }