public DragOperationHost(IUserInputReceiver frameOfReference)
 {
     FrameOfReference = frameOfReference;        
     SnappingEngine = new NoEffectsCanvasItemSnappingEngine();
     IsDragging = false;
 }
 public DragOperationHost(IInputElement frameOfReference)
 {
     FrameOfReference = frameOfReference;
     SnappingEngine = new NoEffectsCanvasItemSnappingEngine();
     IsDragging = false;
 }