ios - 无法将类型“SlideAnimation.Type”的值分配给类型“UIViewControllerTransitioningDelegate”？

我正在尝试将自定义segue动画添加到我的应用中，但始终收到此错误：


  无法将类型“ SlideAnimation.Type”的值分配给类型“ UIViewControllerTransitioningDe”


我的ViewController代码：

import UIKit

class ViewController: UIViewController{
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        let destination = segue.destination
        destination.transitioningDelegate = SlideAnimation
    }
}

我的SlideAnimation.swift代码：

import UIKit

class SlideAnimation: NSObject,UIViewControllerAnimatedTransitioning,UIViewControllerTransitioningDelegate {
    let duration = 0.5

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

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

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

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        guard let toView = transitionContext.view(forKey: UITransitionContextViewKey.to) else{
           return
        }

        let container = transitionContext.containerView
        let screenOffUp = CGAffineTransform(translationX: 0, y: -container.frame.height)
        let screenOffDown = CGAffineTransform(translationX: 0, y:container.frame.height)

        container.addSubview(fromView)
        container.addSubview(toView)

        toView.transform = screenOffUp

        UIView.animate(withDuration: duration, delay: 0.0, usingSpringWithDamping: 0.8, initialSpringVelocity: 0.8, options: [], animations: {
            fromView.transform = screenOffDown
            fromView.alpha = 0.5
            toView.transform = CGAffineTransform.identity
            toView.alpha = 1


        }) {(success) in
            transitionContext.completeTransition(success)
        }
    }
  }
}

我也是Xcode和这个网站的新手，如果还不清楚的话，对不起。

最佳答案

该问题是由以下行引起的：

destination.transitioningDelegate = SlideAnimation

您需要传递一个符合UIViewControllerTransitioningDelegate的类的实例，但是您要传递一个类的名称。

您需要创建SlideAnimation的实例并将其设置为委托：

destination.transitioningDelegate = SlideAnimation()

但这实际上会引起一个新问题，因为transitioningDelegate是弱引用，并将立即变为nil。您需要创建对SlideAnimation实例的强引用。

import UIKit

class ViewController: UIViewController{
    let transitionDelegate = SlideAnimation()

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        let destination = segue.destination
        destination.transitioningDelegate = transitionDelegate
    }
}

关于ios - 无法将类型“SlideAnimation.Type”的值分配给类型“UIViewControllerTransitioningDelegate”？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/49681872/