UIViewControllerAnimatedTransitioning iOS 11 Offset问题

Question

我正在尝试进行自定义转换，我想要一个视图从底部进入焦点。但正如在视频中看到的那样，视图的快照并不完全等于viewcontroller中呈现的内容，因此它最终会产生一个混蛋。

视频链接： https://gfycat.com/RewardingSplendidBoar

你可以看到给予按钮给出一点混蛋。这在iOS 10中不会发生。

我已经添加了 toVC.view.setNeedsLayout（） toVC.view.layoutIfNeeded（） 但仍无济于事。

这是我的代码：

func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        var selected: IndexPath?
        if collectionView.indexPathsForSelectedItems?.count == 0 {
            selected = IndexPath(row: 0, section: 0)
        }
        else {
            selected = collectionView.indexPathsForSelectedItems?[0]
        }
        print("Selected cell: \(String(describing: selected?.row))")
        let cell = collectionView.cellForItem(at: selected!)
        let container: UIView? = transitionContext.containerView
        var fromVC : UIViewController;
        var toVC : UIViewController;
        if isPresenting {
            fromVC = (transitionContext.viewController(forKey: .from) as! ViewController)
            toVC = (transitionContext.viewController(forKey: .to) as! EventDetailVC)
            toVC.view.layoutIfNeeded()
        }else{
            fromVC = (transitionContext.viewController(forKey: .from) as! EventDetailVC)
            toVC = (transitionContext.viewController(forKey: .to) as! ViewController)
        }

        let fromView: UIView? = fromVC.view
        let toView: UIView? = toVC.view

        let beginFrame: CGRect? = container?.convert((cell?.contentView.bounds)!, from: cell?.contentView)
        var endFrame: CGRect = transitionContext.initialFrame(for: fromVC)
        endFrame = toView?.frame ?? CGRect.zero
        var move: UIView? = nil
        var iconBack: UIView? = nil
        var btnGive: UIView? = nil
        var transitionDuration: CGFloat
        if isPresenting {
            transitionDuration = CGFloat(self.duration)
            toView?.frame = endFrame
            move = toView?.snapshotView(afterScreenUpdates: true)
            (toVC as! EventDetailVC).ivBack.alpha = 1
            iconBack = (toVC as! EventDetailVC).ivBack?.snapshotView(afterScreenUpdates: true)
            (toVC as! EventDetailVC).btnGive.alpha = 1
            btnGive = (toVC as! EventDetailVC).btnGive?.snapshotView(afterScreenUpdates: true)
            move?.frame = beginFrame!
            move?.alpha = 0.0
            container?.addSubview(move!)
            container?.addSubview(iconBack!)
            container?.addSubview(btnGive!)
        }
        else {
            transitionDuration =  CGFloat(self.duration)
            move = fromView?.snapshotView(afterScreenUpdates: true)
            move?.frame = (fromView?.frame)!
            fromView?.removeFromSuperview()
            container?.addSubview(move!)
        }

        if isPresenting {
            toVC.view.setNeedsLayout()
            toVC.view.layoutIfNeeded()
            var frame =  (toVC as! EventDetailVC).ivBack.frame;
            frame.origin.x =  (toVC as! EventDetailVC).view.frame.size.width
            iconBack?.frame = frame
            var frame1 =  (toVC as! EventDetailVC).btnGive.frame
            frame1.origin.y =  (toVC as! EventDetailVC).view.frame.size.height
            btnGive?.frame = frame1

            UIView.animate(withDuration: TimeInterval(transitionDuration) , animations: {() -> Void in
                move?.frame =  (toVC as! EventDetailVC).imageView.frame
                move?.alpha = 1.0
                cell?.alpha = 0.0
                iconBack?.frame = (toVC as! EventDetailVC).ivBack.frame
                btnGive?.frame = (toVC as! EventDetailVC).btnGive.frame
            }, completion: {(_ finished: Bool) -> Void in
                iconBack?.removeFromSuperview()
                 btnGive?.removeFromSuperview()
                move?.removeFromSuperview()
                toView?.frame = endFrame
                container?.addSubview(toView!)
                transitionContext.completeTransition(true)
            })
        }
        else {
            cell?.isHidden = false
            cell?.alpha = 0.0

            UIView.animate(withDuration: TimeInterval(transitionDuration), animations: {
                move?.frame = beginFrame!
                move?.alpha = 0.0
                cell?.alpha = 1.0
            }, completion: { (_ finished: Bool) in
                cell?.isHidden = false
                transitionContext.completeTransition(true)
            })
        }
    }