IOS：UILongPressGestureRecognizer EXC_BAD_ACCESS

Question

I have this code in viewDidLoad:

UILongPressGestureRecognizer *change = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(dragGestureChange:)];
    [imageView addGestureRecognizer:change];
    for (UILongPressGestureRecognizer *gestureRecognizer in imageView.gestureRecognizers)
    {
        [gestureRecognizer requireGestureRecognizerToFail:change];
    }

when I call the class where is this code, the first time it's all ok , but the second time it crash because EXC_BAD_ACCESS; it don't happens if instead of an imageView I use a scrollView, why???

Answer 1

With this code, you are requiring all recognizers (including change) to fail for change to succeed, which cannot be good

UILongPressGestureRecognizer *change = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(dragGestureChange:)];
[imageView addGestureRecognizer:change];
for (UILongPressGestureRecognizer *gestureRecognizer in imageView.gestureRecognizers)
{
    [gestureRecognizer requireGestureRecognizerToFail:change];
}

you should change it to this

UILongPressGestureRecognizer *change = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(dragGestureChange:)];
for (UILongPressGestureRecognizer *gestureRecognizer in imageView.gestureRecognizers)
{
    [gestureRecognizer requireGestureRecognizerToFail:change];
}
[imageView addGestureRecognizer:change];

And you should release change here. Don't know if that will actually solve your problem, can't see anything else wrong in what you posted.

Answer 2

Maybe try this: UIButtonLongTab . Use the Background-Image for your Images. I use this in an App within a ScrollView and it works without problem.