问题描述:

I am receiving crash reports that appear to be from a UIView animation calling a delegate that has been dealloced.

 Thread 0 Crashed:

0 libobjc.A.dylib 0x334776f6 objc_msgSend + 18

1 UIKit 0x31c566c4 -[UIViewAnimationState sendDelegateAnimationDidStop:finished:]

2 UIKit 0x31c565d2 -[UIViewAnimationState animationDidStop:finished:]

3 QuartzCore 0x30045a26 run_animation_callbacks

I am setting the current view controller as the delegate for animations using the following pattern:

[UIView beginAnimations:nil context:NULL];

[UIView setAnimationBeginsFromCurrentState:YES];

[UIView setAnimationDuration:0.5];

[UIView setAnimationDelegate:self];

...

[UIView commitAnimations];

My question is, how do I set that delegate reference to nil in my dealloc method? Is there some way to retain a reference to an animation? Or fetch animations in progress?

网友答案:

The CALayer class handles all animations for UIViews. You can access the UIView's layer using the layer property. If you were to replace the first argument of [UIView beginAnimations: context:] with an actual string, it would be possible to access that animation directly using CALayer's animationForKey: and removeAnimationForKey: methods.

In this case though, it might be enough to call [view.layer removeAllAnimations] before dealloc calls [super dealloc]. This will stop any custom UIView animations and, obviously, remove them from its layer.

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