UIPinchGestureRecognizer questions with subviews - ios

Question

I have the following code:
m_singleView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, nWidth - 1, nHeight - 1)];
m_singleView.backgroundColor = [UIColor clearColor];
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(pinch:)];
[pinchGesture setCancelsTouchesInView:YES];
[m_singleView addGestureRecognizer:pinchGesture];
[m_singleView setUserInteractionEnabled:YES];
[m_MainView addSubview:m_singleView];
The issue that I'm having is that the pinch event for some reason does not fire. However, if i change line from [m_singleView addGestureRecognizer:pinchGesture] to [m_MainView addGestureRecognizer:pinchGesture]; then everything will work fine... can I not add the event for subview only?
Thanks!

Answer 1

Yes,you can add gesture to subview. i tested your code like below works fine.
First add delegate.
#interface ViewController : UIViewController<UIGestureRecognizerDelegate>
- (void)viewDidLoad {
[super viewDidLoad];
UIView *m_singleView = [[UIView alloc] initWithFrame:CGRectMake(50, 50, self.view.frame.size.width - 50, self.view.frame.size.height - 50)];
self.view.backgroundColor=[UIColor greenColor];
m_singleView.backgroundColor = [UIColor redColor];
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(pinch)];
pinchGesture.delegate=self;
[pinchGesture setCancelsTouchesInView:YES];
[m_singleView addGestureRecognizer:pinchGesture];
[m_singleView setUserInteractionEnabled:YES];
[self.view addSubview:m_singleView];
}
-(void)pinch{
NSLog(#"In PInch");
}
you have used pinchgesture so you can use it like below.

Answer 2

Use Debug view hierarchy to see whether the size of m_singleView are 0 or not? If so, the size of m_singleView needs to be changed until you can touch it.