iOS7 UIModalTransitionStyleFlipHorizontal bounces

问题:

I'm updating my app for iOS 7 and I discovered a weird problem. I'm presenting a UIViewController wrapped in a UINavigationController with UIModalTransitionStyleFlipHorizontal.

In iOS 6 it works fine, but in iOS 7 the navigation bar bounces after the transition. Does this have something to do with the status bar? I've set translucency of the main navigation bar to NO.

In the Info.plist, View controller-based status bar appearance is set to NO.

And here is a GIF showing the problem in a minimal demo app:

Here is my code:

feedNavigationController = [[UINavigationController alloc] init];
feedNavigationController.navigationBar.translucent = NO;

SettingsViewController *settingsVC = [[SettingsViewController alloc] init];

feedNavigationController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[feedNavigationController setViewControllers:[NSArray arrayWithObjects:settingsVC, nil]];

[self presentViewController:feedNavigationController animated:YES completion:nil];

回答1:

This appears to be a UIKit bug. The following workaround seems to resolve the issue for me.

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    [self.navigationController.navigationBar.layer removeAllAnimations];
}

(Place this in the view controller you are transitioning to).

回答2:

To solve this problem for present & dismiss, I use the iOS7 custom transition.

Add this to your UIViewController :

- (id <UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source {
    return (id<UIViewControllerAnimatedTransitioning>)self;
}

- (id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed {
    return (id<UIViewControllerAnimatedTransitioning>)self;
}

- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext {
    return 0.7f;
}

- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext {
    UIView *containerView = [transitionContext containerView];


    UIViewController *fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    [containerView addSubview:fromVC.view];

    UIViewController *toVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    [containerView addSubview:toVC.view];

    UIViewAnimationOptions animationOption = ([toVC.presentedViewController isEqual:fromVC])?UIViewAnimationOptionTransitionFlipFromLeft:UIViewAnimationOptionTransitionFlipFromRight;


    [UIView transitionFromView:fromVC.view
                        toView:toVC.view
                      duration:[self transitionDuration:transitionContext]
                       options:animationOption
                    completion:^(BOOL finished) {
                        [transitionContext completeTransition:YES];
                    }];
}

To use it, you just had to check if you are on iOS7 and set the transitionDelegate :

YourVCWithTheCustomTransition* yourVC = [[YourVCWithTheCustomTransition alloc] init];

CGFloat deviceVersion = [UIDevice currentDevice].systemVersion.floatValue;
if(deviceVersion >= 7.0) [yourVC setTransitioningDelegate:yourVC];

[self presentModalViewController:yourVC animated:YES];
[yourVC release];

In my case, I had a custom UINavigationController where the custom transition is defined : i don't have to do this each time.

回答3:

This appears to be a UIKit bug. The following workaround seems to resolve the issue for me.

presentViewController (place this in the view controller you are transitioning to):

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    [self.navigationController.navigationBar.layer removeAllAnimations];
}

dismissViewControllerAnimated (place this in the view controller you dismiss to):

- (void)viewWillLayoutSubviews{
    [super viewWillLayoutSubviews];

    [self.navigationController.navigationBar.layer removeAllAnimations];
}

if you don't use autolayout. you need add this to the view controller you dismiss to:

- (void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];

    [self.view setNeedsLayout];
} 

回答4:

I had the same issue and could "solve it" (it's not a real solution to the problem but it looks fine :) ). The trick is present the view controller using pushViewController/popViewController with an UIView animation to make a flip. Here is a example code to present the view controller:

UIViewController *viewController = [[UIViewController alloc] init];
[UIView transitionWithView:self.navigationController.view 
                  duration:0.5 
                   options:UIViewAnimationOptionTransitionFlipFromLeft 
                animations:^{
                   [self.navigationController pushViewController:viewController animated:NO];
                }
                completion:nil];

To dismiss it:

[UIView transitionWithView:self.navigationController.view 
                  duration:0.5 
                   options:UIViewAnimationOptionTransitionFlipFromRight 
                animations:^{
                   [self.navigationController popViewControllerAnimated:NO];
                }
                completion:nil];

If you don't want the navigationBar on the pushed controller just call [self.navigationController setNavigationBarHidden:YES animated:NO] in viewWillAppear. I hope this approach help you.

回答5:

For both the presenting and the presented view controller I have a UITableViewController within UINavigationController, both configured using Auto Layout. I noticed that the other answers didn't solve the problem that on dismiss the tableView of the presenting view controller jumps 20 pt vertically.

This solution addresses this problem.

In the presented view controller (as proposed by Ben Packard):

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [self.navigationController.navigationBar.layer removeAllAnimations];
}

In the presenting view controller (as proposed in part by dusty):

- (void)viewWillLayoutSubviews{
    if (self.navigationController.presentedViewController) {
        [self.navigationController.navigationBar.layer removeAllAnimations];
        [self.tableView.layer removeAllAnimations];
    }
    [super viewWillLayoutSubviews];
}

回答6:

The same for me. What actually worked is to change style to CoverVertical, looks much smoother.