ios - 动画期间的帧值错误

Question

我想制作一个像iOS主屏幕文件夹一样的动画。我在主视图 Controller 中有一个容器 View ，在容器 View 中我用动画在两个 View Controller 之间切换。
这是主视图 Controller 类的代码:

class MainContainerViewController: UIViewController {

    @IBOutlet weak var containerView: UIView!

    let duration = 1.0
    var presenting = true
    var originFrame = CGRect.zero
    var indexPathSelectedCell: IndexPath?

    var dismissCompletion: (()->())?


    func cycle(fromViewController: UIViewController, toViewController: UIViewController) {

        let folderViewC = (presenting ? fromViewController : toViewController) as! ViewController
        let projectViewC = (presenting ? toViewController : fromViewController) as! ProjectViewController

        let cellView = (presenting ? (folderViewC.folderCollectionView.cellForItem(at: folderViewC.folderCollectionView.indexPathsForSelectedItems!.first!) as! FolderCollectionViewCell).folderView : projectViewC.containerView)!
        let cellSnapshot = cellView.snapshotView(afterScreenUpdates: false)!
        let cellFrame = containerView.convert(cellView.frame, from: cellView.superview)
        cellSnapshot.frame = cellFrame
        cellView.isHidden = true

        toViewController.view.frame = self.containerView.frame
        toViewController.view.layoutIfNeeded()
        toViewController.view.alpha = 0


        presenting ? (projectViewC.containerView.isHidden = true) : ((folderViewC.folderCollectionView.cellForItem(at: self.indexPathSelectedCell!) as! FolderCollectionViewCell).folderView.isHidden = true)

        fromViewController.willMove(toParentViewController: nil)
        self.addChildViewController(toViewController)
        self.containerView.addSubview(toViewController.view)
        self.containerView.addSubview(cellSnapshot)

        UIView.animate(withDuration: duration, animations: {


            toViewController.view.alpha = 1.0

            let finalFrame = self.presenting ? projectViewC.containerView.frame : self.containerView.convert((folderViewC.folderCollectionView.cellForItem(at: self.indexPathSelectedCell!) as! FolderCollectionViewCell).folderView.frame, from: (folderViewC.folderCollectionView.cellForItem(at: self.indexPathSelectedCell!) as! FolderCollectionViewCell).folderView.superview)

            cellSnapshot.frame = finalFrame
        }) { (_) in

            if !self.presenting {
                self.dismissCompletion?()
            }

            self.presenting ? (projectViewC.containerView.isHidden = false) : ((folderViewC.folderCollectionView.cellForItem(at: self.indexPathSelectedCell!) as! FolderCollectionViewCell).folderView.isHidden = false)

            cellSnapshot.removeFromSuperview()
            fromViewController.view.removeFromSuperview()
            fromViewController.removeFromParentViewController()
            toViewController.didMove(toParentViewController: nil)

        }

    }

}

除 let finalFrame = self.presenting ? projectViewC.containerView.frame : self.containerView.convert((folderViewC.folderCollectionView.cellForItem(at: self.indexPathSelectedCell!) as! FolderCollectionViewCell).folderView.frame, from: (folderViewC.folderCollectionView.cellForItem(at: self.indexPathSelectedCell!) as! FolderCollectionViewCell).folderView.superview) 外，所有代码均正常工作那套finalFrame错误的值:

• 当它呈现时，快照会出现在屏幕中间
• 当它关闭时，快照会靠近他的正确位置。

let finalFrame = self.presenting ? projectViewC.containerView.frame : self.containerView.convert((folderViewC.folderCollectionView.cellForItem(at: self.indexPathSelectedCell!) as! FolderCollectionViewCell).folderView.frame, from: (folderViewC.folderCollectionView.cellForItem(at: self.indexPathSelectedCell!) as! FolderCollectionViewCell).folderView.superview)线路的工作方式如下:

• 检查是否显示
• 如果正在呈现，则将常量设置为最终文件夹 View 的帧值
• 如果关闭，则从该folderView的 super View 中转换所选 Collection View 单元格的folderView的frame值

这是整个项目:https://github.com/ale00/OnteamAnon

Answer 1

由于您在projectViewController中使用自动布局来调整containerView的大小，因此您需要在这部分代码之后对self.containerView调用layoutIfNeeded() :

self.addChildViewController(toViewController)
self.containerView.addSubview(toViewController.view)
self.containerView.addSubview(cellSnapshot)

所以就变成了:

self.addChildViewController(toViewController)
self.containerView.addSubview(toViewController.view)
self.containerView.addSubview(cellSnapshot)
self.containerView.layoutIfNeeded()