iOS11中的自定义展开segue崩溃

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玩弄这个我发现如果我从提供的控制器中执行此操作，一切都会按预期工作：

self.dismiss(animated: true)

然后自定义 segue 的动画被执行。但是，如果我尝试使用这样的 unwind segue：

self.performSegue(withIdentifier: "logoDisplayed", sender: self)

然后我得到下面提到的崩溃。此外，我发现自定义 segue 仅在我将“种类”设置为“模态呈现”时才有效。如果我将其设置为“自定义”，那么我会再次收到崩溃消息，告诉我没有 perform()，即使显然有。

仍在尝试解决这个问题。

原帖

我知道之前已经讨论过这个问题（here、here 和 here）

但我无法在 iOS11 中使用自定义展开转场。下面是我正在使用的自定义 segue。当我将它设置为模型转场的类时它可以完美运行，但是当我将它设置为展开转场的类时它不起作用。相反，应用程序因以下错误而崩溃：

2017-11-20 22:29:09.640934+1100 Crux[46709:6046351] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', 
reason: 'Could not perform segue with identifier 'logoDisplayed'. 
A segue must either have a performHandler or it must override -perform.'
*** First throw call stack:
(
0   CoreFoundation                      0x00000001100c012b __exceptionPreprocess + 171
1   libobjc.A.dylib                     0x000000010f06bf41 objc_exception_throw + 48
2   UIKit                               0x0000000111c1061d -[UIStoryboardSegue _prepare] + 0
3   Crux                                0x000000010dacecc8 _T04Crux13AnimatedSegueC7performyyF + 280
...

segue 的设置如下：

我的 segue 的代码是这样的：

class FadeInAnimator: NSObject, UIViewControllerAnimatedTransitioning {

    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 2.0
    }

    func animateTransition(using transitionContext:      UIViewControllerContextTransitioning) {

        let containerView = transitionContext.containerView
        let toVC = transitionContext.viewController(forKey:UITransitionContextViewControllerKey.to)

        containerView.addSubview(toVC!.view)
        toVC!.view.alpha = 0.0

        let duration = transitionDuration(using:transitionContext)
        UIView.animate(withDuration:duration,
                       animations: {
                        toVC!.view.alpha = 1.0
        },
                       completion: { finished in
                        let cancelled = transitionContext.transitionWasCancelled
                        transitionContext.completeTransition(!cancelled)
        })
    }
}

class AnimatedSegue:UIStoryboardSegue, UIViewControllerTransitioningDelegate {

    override func perform() {
        source.transitioningDelegate = self
        destination.transitioningDelegate = self
        super.perform()
    }

    func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        return FadeInAnimator()
    }

    func animationController(forPresented presented: UIViewController,
                             presenting: UIViewController,
                             source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        return FadeInAnimator()
    }
}

有人知道我哪里出错了吗？

Answer 1

发现问题。我在源控制器中有一些旧代码：

override func segueForUnwinding(to toViewController: UIViewController, from fromViewController: UIViewController, identifier: String?) -> UIStoryboardSegue? {
    return AnimatedSegue(identifier: identifier, source: fromViewController, destination: toViewController)
}

哪个被调用并导致问题。