Question

使用UIModalPresentationCustom关闭各种视图控制器时，视图控制器关闭后屏幕变黑，就像所有视图控制器已从视图层次结构中删除一样。

正确设置转换委托，正确地请求并传递animationControllerForPresentedController，并在动画结束后完成转换。

这个确切的代码在使用iOS 7 SDK编译时效果很好，但在使用iOS 8b5编译时会损坏

Answer 1

这是因为您最有可能同时添加演示文稿

[transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey]

和呈现的

[transitionContext viewControllerForKey:UITransitionContextToViewControllerKey]

在动画控制器的（void）animateTransition：（id）transitionContext方法中查看控制器到您的containerView。由于您使用的是自定义模式演示文稿，呈现视图控制器仍显示在呈现的视图控制器下方。现在，由于它仍然可见，因此您无需将其添加到容器视图中。而仅将呈现的视图控制器添加到containerView。应该在animateTransition：method

中看起来像这样

UIView *containerView = [transitionContext containerView];
UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

// Boolean value to determine presentation or dismissal animation
if (self.presenting){        
    [transitionContext.containerView addSubview:toViewController.view];
    // Your presenting animation code
} else {
    // Your dismissal animation code
}

Answer 2

这是高票和高票的问题。接受回答误导人。长话短说。

首先，不要使用UIModalPresentationCustom，它听起来不像。（detail）

其次，有一种新方法可以在animateTransition中从/向视图中检索，不再使用'fromVC.view'这样的内容。（why）

UIViewController *fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
UIViewController *toVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
UIView *fromView = [transitionContext viewForKey:UITransitionContextFromViewKey];
UIView *toView = [transitionContext viewForKey:UITransitionContextToViewKey];

//swift
let fromVC = transitionContext.viewControllerForKey(UITransitionContextFromViewControllerKey)
let toVC = transitionContext.viewControllerForKey(UITransitionContextToViewControllerKey)
let fromView = transitionContext.viewForKey(UITransitionContextFromViewKey)
let toView = transitionContext.viewForKey(UITransitionContextToViewKey)

现在黑屏应该消失。

Answer 3

我似乎遇到了同样的问题，我正在使用Xcode 6 beta5。

我在谷歌搜索并发现其他人也有同样的问题，他们说这是iOS 8中的一个严重错误，所以希望Apple能尽快解决这个问题。

https://github.com/TeehanLax/UIViewController-Transitions-Example/issues/5

Answer 4

我将下面的代码添加到转换完成块中，并为我修复了它。

[UIView animateWithDuration:[self transitionDuration:transitionContext] animations: ^{
    // Animation code

 } completion: ^(BOOL finished) {
     // More of your code

     // Add the following line before completing the transition
    [[[UIApplication sharedApplication] keyWindow] sendSubviewToBack:toViewController.view];

    // Complete the transition
    [transitionContext completeTransition:YES];
}];

Answer 5

也许视图层次结构对于新的Xcode来说是错误的，或者它与iOS8有点不同。这段代码对我有用。在animateTransition：transitionContext方法中解除控制器时添加它。

[[UIApplication sharedApplication].keyWindow addSubview:toViewController.view];
toViewController.view.userInteractionEnabled = YES;

Answer 6

快速提示：确保您的＆＃34; From＆＃34; UIViewController是你期待的。

    NSLog(@" FROM vc %@" , [[transitionContext  viewControllerForKey:UITransitionContextFromViewControllerKey] description]);

过去我的代码中有类似的错误。你可以很容易地找出正确的＆＃34;来自＆＃34; VC背景。

  UIViewController *fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];  
  fromView =  [[[fromVC childViewControllers] firstObject]  view];

Answer 7

我遇到了同样的问题，导致问题的原因是我没有设置toViewController的最终帧。请参阅http://www.appcoda.com/custom-view-controller-transitions-tutorial/

中的以下示例

func animateTransition(transitionContext: UIViewControllerContextTransitioning) {

    let fromViewController = transitionContext.viewControllerForKey(UITransitionContextFromViewControllerKey)!
    let toViewController = transitionContext.viewControllerForKey(UITransitionContextToViewControllerKey)!
    let finalFrameForVC = transitionContext.finalFrameForViewController(toViewController)
    let containerView = transitionContext.containerView()
    let bounds = UIScreen.mainScreen().bounds
    toViewController.view.frame = CGRectOffset(finalFrameForVC, 0, bounds.size.height)
    containerView.addSubview(toViewController.view)

    UIView.animateWithDuration(transitionDuration(transitionContext), delay: 0.0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.0, options: .CurveLinear, animations: {
        fromViewController.view.alpha = 0.5
        toViewController.view.frame = finalFrameForVC
    }, completion: {
        finished in
        transitionContext.completeTransition(true)
        fromViewController.view.alpha = 1.0
    })
}

iOS 8 - 使用自定义演示文稿解除视图控制器后屏幕空白

7 个答案: