自定义水平弹出过渡无法正常工作

Question

我正在尝试创建自定义水平幻灯片 UINavigationController 过渡。并且推送动画似乎工作正常。但是当我试图弹出（并让水平滑动回来）只有一个空白屏幕并且在动画时间之后视图出现在它应该出现的位置时

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {

        let container = transitionContext.containerView
        let fromView = transitionContext.view(forKey: UITransitionContextViewKey.from)!
        let toView = transitionContext.view(forKey: UITransitionContextViewKey.to)!

        let offScreenRight = CGAffineTransform(translationX: container.frame.width, y: 0)
        let offScreenLeft = CGAffineTransform(translationX: -container.frame.width, y: 0)

        fromView.frame = transitionContext.initialFrame(for: transitionContext.viewController(forKey: .from)!)
        toView.frame = transitionContext.finalFrame(for: transitionContext.viewController(forKey: .to)!)

        toView.transform = isPresenting == true ? offScreenRight : offScreenLeft



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

        let duration = self.transitionDuration(using: transitionContext)

        UIView.animate(withDuration: duration, delay: 0.0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.8, options: [], animations: {

            fromView.transform = self.isPresenting == true ? offScreenLeft : offScreenRight
            toView.transform = .identity

        }, completion: { finished in

            toView.frame = transitionContext.initialFrame(for: transitionContext.viewController(forKey: .from)!)
            transitionContext.completeTransition(true)
        })
    }

Answer 1

您似乎需要重置视图上的所有现有转换。

func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {

    let container = transitionContext.containerView
    let fromView = transitionContext.view(forKey: UITransitionContextViewKey.from)!
    let toView = transitionContext.view(forKey: UITransitionContextViewKey.to)!

    // add these two lines      
    fromView.transform = .identity
    toView.transform = .identity

    // ... the rest of your existing code