iOS 9: push/pop view controller broken by edgesForExtendedLayout

问题

I have found a strange issue while debugging on iOS 9. In my View Controller's viewDidLoad I have this piece of code:

if ([self respondsToSelector:@selector(edgesForExtendedLayout)]) {
    self.edgesForExtendedLayout = UIRectEdgeNone;
}

When I am pushing or popping a new view controller I have noticed a strange animation. The transition isn't smooth and it seems like it is displaying a "stack" of view controllers (you can notice the top and even slightly a bottom of both images).

I had no problem on iOS 7 or iOS8, is this a bug of the newly released iOS 9 or am I missing something?

It's also worth to mention that I am using custom animation for push/pop view controller transition.

Here is an example of one of the overriden UINavigationController methods

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    UIView *theWindow = self.view;
    [[theWindow layer] removeAllAnimations];

    if (animated) {
        CATransition *animation = [CATransition animation];
        [animation setDuration:0.25];
        [animation setType:kCATransitionFade];
        [animation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]];
        [[theWindow layer] addAnimation:animation forKey:@""];
    }

    [super pushViewController:viewController animated:NO];
}

EDIT:

I have been debugging this issue for couple of hours now. I have reimplemented the custom animations following API for view controllers transitions introduced in iOS 7 (navigationController:animationControllerForOperation:operation fromViewController:toViewController) but the issue persists.

The problem happens if the transition is animating alpha property.

Do you have an idea how to overcome this issue?

Thanks.

回答1:

You need to setup final frame for toViewController. transitionContext.finalFrame(for:) can help you to determine it. Something like:

toViewController.view.frame = transitionContext.finalFrame(for: toViewController)

来源：https://stackoverflow.com/questions/32700122/ios-9-push-pop-view-controller-broken-by-edgesforextendedlayout