iOS 7.1 removeFromSuperview crash

Question

My app didn\'t have any crash until iOS 7.1 came out. Now on any removeFromSuperview method, crash. For example: I got view controllers, and when I

Answer 1

It's usually not a good idea to modify an array while you're fast enumerating it. You appear to be using fast enumeration on a a view's array of subviews, and to be modifying that array at the same time (by removing subviews as you go). You could try something like this:

NSArray *subviewsCopy = [[contentVc subviews] copy];
for (UIView *subview in subviewsCopy) {
    [subview removeFromSuperview];
}

However, as some others have mentioned, it's a little odd that you need to go to the trouble of removing these subviews manually. Under normal circumstances a view controller's view (and the view hierarchy under it) will be cleaned up automatically when the view controller itself is deallocated.

There are also some good tools available that can help you track down the source of the issue. In particular, you should profile your app (in Xcode, under the Product menu) and choose the Zombies tool when Instruments prompts you. With Zombies you can see the retain/release history of an object that was messaged after it was deallocated.

If you're attempting this manual cleanup of the view hierarchy because you suspect that your views will be leaked otherwise, I suggest that you also try the Leaks tool in Instruments and verify that when this code is disabled the relevant views are actually leaked.