C# UIGestureRecognizer类代码示例

 public void OnDoubleTap(UIGestureRecognizer sender)
 {
     if (scrollView.ZoomScale >= 1)
     scrollView.SetZoomScale(0.25f, true);
      else
     scrollView.SetZoomScale(2f, true);
 }

        protected void AddGestureRecognizer(UIView target, UIGestureRecognizer tap)
        {
            if (!target.UserInteractionEnabled)
                target.UserInteractionEnabled = true;

            target.AddGestureRecognizer(tap);
        }

 //implement doubletap handler
 private void OnDoubleTap(UIGestureRecognizer gesture)
 {
     if (scrollView.ZoomScale >= 1)
         scrollView.SetZoomScale(0.25f, true);
     else
         scrollView.SetZoomScale(2f, true);
 }

		public override bool GestureRecognizerShouldBegin (UIGestureRecognizer gestureRecognizer)
		{
			if (gestureRecognizer.GetType () == typeof (UIPinchGestureRecognizer) && padTouch != null)
				return false;

			return true;
		}

 public override bool ShouldBegin(UIGestureRecognizer recognizer)
 {
     if (recognizer == Layout.PanGestureRecognizer)
     {
         return Layout.SelectedItemIndexPath != null;
     }
     return true;
 }

 public bool ShouldBegin(UIGestureRecognizer recognizer)
 {
     if (recognizer is UIScreenEdgePanGestureRecognizer &&
         ViewControllers.Length == 1) {
         return false;
     }
     return true;
 }

		private void OnSoloTap(UIGestureRecognizer gesture)
		{
			CGPoint touchPoint = new CGPoint (gesture.LocationInView(scrollView));
			if(imageView.Frame.Contains(touchPoint))
			{
				Console.WriteLine ("збс");
			}			
		}

 public override bool ShouldRecognizeSimultaneously(UIGestureRecognizer gestureRecognizer, UIGestureRecognizer otherGestureRecognizer)
 {
     if (gestureRecognizer == Layout.LongPressGestureRecognizer)
     {
         return Layout.PanGestureRecognizer == otherGestureRecognizer;
     }
     if (gestureRecognizer == Layout.PanGestureRecognizer)
     {
         return Layout.LongPressGestureRecognizer == otherGestureRecognizer;
     }
     return false;
 }

		// Ensure that the pinch, pan and rotate gestures are all recognized simultaneously
		public override bool ShouldRecognizeSimultaneously (UIGestureRecognizer gestureRecognizer, UIGestureRecognizer otherGestureRecognizer)
		{	
			// if the gesture recognizers views differ, don't recognize
			if (gestureRecognizer.View != otherGestureRecognizer.View)
				return false;
			
			// if either of the gesture recognizers is a long press, don't recognize
			if (gestureRecognizer is UILongPressGestureRecognizer || otherGestureRecognizer is UILongPressGestureRecognizer)
				return false;
			
			return true;
		}

		//implement doubletap handler
		private void OnDoubleTap (UIGestureRecognizer gesture) 
		{
		/*	TouchesBegan += (NSSet touches, UIEvent evt) => {
				Console.WriteLine ("TouchesBegan works");
				base.TouchesBegan (touches, evt);
			}; */

			if (scrollView.ZoomScale >= 1)
			{
				scrollView.SetZoomScale(0.25f, true);
			}
			else
			{
				scrollView.SetZoomScale(2f, true);
			}
		}	

			// Ensure that the pinch, pan and rotate gestures are all recognized simultaneously
			public override bool ShouldRecognizeSimultaneously (UIGestureRecognizer gestureRecognizer, UIGestureRecognizer otherGestureRecognizer)
			{
				// if the gesture recognizers's view isn't one of our images don't recognize
				if (gestureRecognizer.View != controller.firstImage &&
					gestureRecognizer.View != controller.secondImage &&
					gestureRecognizer.View != controller.thirdImage)
					return false;
				
				// if the gesture recognizers views differ, don't recognize
				if (gestureRecognizer.View != otherGestureRecognizer.View)
					return false;
				
				// if either of the gesture recognizers is a long press, don't recognize
				if (gestureRecognizer is UILongPressGestureRecognizer || otherGestureRecognizer is UILongPressGestureRecognizer)
					return false;
				
				return true;
			}

 public override bool CanBePreventedByGestureRecognizer(UIGestureRecognizer preventingGestureRecognizer)
 {
     return !CancelsTouchesInView;
 }

		async void HandleTapGestureAsync (UIGestureRecognizer tap)
		{
			if (tap.State == UIGestureRecognizerState.Recognized) {

				UIImage image;

				UIGraphics.BeginImageContextWithOptions(UIScreen.MainScreen.Bounds.Size, true, 0);

				UIApplication.SharedApplication.Windows[0].DrawViewHierarchy(UIScreen.MainScreen.Bounds, false);

				image = UIGraphics.GetImageFromCurrentImageContext();

				UIGraphics.EndImageContext();

//				image.SaveToPhotosAlbum((i, e) => {
//					
//				});

				await TrapState.Shared.AddSnapshotImageForSdk(image);

				// BugTrapState.SnapshotImage = image;

				var storyboard = UIStoryboard.FromName("bugTrapKit", NibBundle);

				var navController = storyboard.Instantiate<BtAnnotateImageNavigationController>();

				PresentViewController(navController, false, null);
			}
		}

 /// <summary>
 /// Gestures the recognizer should begin.
 /// </summary>
 /// <returns><c>true</c>, if recognizer should begin was gestured, <c>false</c> otherwise.</returns>
 /// <param name="gestureRecognizer">Gesture recognizer.</param>
 public override bool GestureRecognizerShouldBegin(UIGestureRecognizer gestureRecognizer)
 {
     return true;
 }

 internal bool shouldReceiveTouch(UIGestureRecognizer gesture, UITouch touch)
 {
     if (ShouldReceiveTouch != null)
         return ShouldReceiveTouch(gesture, touch);
     return true;
 }