Question

I adding subviews programmatic. for each subview I’m adding a gesture reconognizer:

UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
    imageView.frame = CGRectMake((position*1024)+200,0,image.size.width,image.size.height);
    UITapGestureRecognizer *singleFingerTap = [[UITapGestureRecognizer alloc]
                                               initWithTarget:self action:@selector(singleFingerTap:)];
    singleFingerTap.numberOfTapsRequired = 1;
    [imageView addGestureRecognizer:singleFingerTap];
    [singleFingerTap release];

but the tap is not responding how can I verify the gesture has been add it to the subview ?

Answer 1

Add this after your code:

NSLog(@"imageView.gestureRecognizers: %@", [imageView.gestureRecognizers description]);

If you have properly added gestureRecognizers it will print the description of each to the console. If not, it will show (NULL) or an empty array in the console.

---

You can also set the gesture recognizer delegate:

[singleFingerTap setDelegate:self];

Then add the delegate method and set a break point to make sure it is getting called:

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
    NSLog(@"gestureRecognizerShouldBegin: called");
    return YES;
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
    NSLog(@"shouldReceiveTouch: called");
    return YES;
}