所以我有 2 个 View Controller ，我想使用自定义动画从 view controller 1 到 view controller 2。这是我的自定义动画的代码:

let transition = CATransition()
transition.duration = 0.5
transition.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionDefault)
transition.type = kCATransitionPush
transition.subtype = kCATransitionFromRight
self.view.window?.layer.add(transition, forKey: nil)

我在调用 performSegue() 之前运行了它，它起作用了。但我想做的是在 view controller 2 的代码中，我想在 segue 动画完成后运行一些东西(所以在 0.5 秒之后)。我的 View Controller 不是导航 Controller 的一部分，所以 this post没有帮助。我还希望我的代码位于目标 View Controller 中，但是this post在源 View Controller 中有它，所以这也无济于事。

我已经尝试测试 viewDidLoad() 和 viewDidAppear()，但它们都在滑动动画完成之前运行。请帮忙，谢谢!

最佳答案

当您正确设置过渡动画时，viewDidAppear 将在动画完成时被调用。参见 Customizing Transition Animations在 iOS View Controller Programming Guide 中获取有关自定义两个 View Controller 之间转换的正确方法的说明。

正如该指南所说，当您想要自定义模式转换时，您应该指定一个 modalPresentationStyle .custom 然后指定 transitioningDelegate它将提供:

• 演示 Controller ；
• 用于呈现模态的动画 Controller ；和
• 用于关闭模态的动画 Controller

例如，目标 View Controller 将指定它将执行自定义转换:

class ViewController: UIViewController {

    // if storyboards, override `init(coder:)`; if NIBs or programmatically 
    // created view controllers, override the appropriate `init` method.

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

        transitioningDelegate = self
        modalPresentationStyle = .custom
    }

    ...

}

并且，在其 UIViewControllerTransitioningDelegate 中，它提供了演示 Controller 和动画 Controller :

extension ViewController: UIViewControllerTransitioningDelegate {
    func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        return TransitionAnimator(operation: .present)
    }

    func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        return TransitionAnimator(operation: .dismiss)
    }

    func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
        return PresentationController(presentedViewController: presented, presenting: presenting)
    }
}

所有呈现 Controller 所做的就是指定当转换完成时呈现者的 View 应该从 View 层次结构中删除(这是经验法则，除非呈现 View 是半透明的或不覆盖整个屏幕):

class PresentationController: UIPresentationController {
    override var shouldRemovePresentersView: Bool { return true }
}

然后动画师指定动画的持续时间和特定细节:

class TransitionAnimator: NSObject {

    enum TransitionOperation {
        case present
        case dismiss
    }

    private let operation: TransitionOperation

    init(operation: TransitionOperation) {
        self.operation = operation
        super.init()
    }
}

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

    func animateTransition(using context: UIViewControllerContextTransitioning) {
        let toVC = context.viewController(forKey: .to)!
        let fromVC = context.viewController(forKey: .from)!
        let container = context.containerView

        let frame = fromVC.view.frame
        let rightFrame = CGRect(origin: CGPoint(x: frame.origin.x + frame.width, y: frame.origin.y), size: frame.size)
        let leftFrame = CGRect(origin: CGPoint(x: frame.origin.x - frame.width, y: frame.origin.y), size: frame.size)

        switch operation {
        case .present:
            toVC.view.frame = rightFrame
            container.addSubview(toVC.view)
            UIView.animate(withDuration: transitionDuration(using: context), animations: {
                toVC.view.frame = frame
                fromVC.view.frame = leftFrame
            }, completion: { finished in
                fromVC.view.frame = frame
                context.completeTransition(!context.transitionWasCancelled)
            })

        case .dismiss:
            toVC.view.frame = leftFrame
            container.addSubview(toVC.view)
            UIView.animate(withDuration: transitionDuration(using: context), animations: {
                toVC.view.frame = frame
                fromVC.view.frame = rightFrame
            }, completion: { finished in
                fromVC.view.frame = frame
                context.completeTransition(!context.transitionWasCancelled)
            })
        }
    }
}

显然，您可以制作任何您想制作的动画，但希望您能掌握基本概念。最重要的是，目标 View Controller 应该指定它的 transitioningDelegate 然后你可以做一个标准的模态展示(通过 present 或 show 或者只是一个 segue)，你的过渡动画将是自定义，您目的地的 viewDidAppear 将在动画完成时调用。

关于ios - swift 4 - 如何在 segue 动画完成后在目标 View Controller 中运行代码？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/49968080/