点击表格视图单元格中的视频以在视图控制器中打开它

Posted 2023-03-13

【中文标题】点击表格视图单元格中的视频以在视图控制器中打开它

【英文标题】：Tapping on a video in a table view cell to open it in a view controller

【发布时间】：2021-05-13 17:19:46

【问题描述】：

tl;dr 我正在尝试在 Twitter 应用中重新创建它：https://i.imgur.com/173CVyM.mp4

如您所见，Twitter 在提要（表格视图单元格）中播放视频，当点击视频时，视频会平滑过渡到其自己的视图控制器，而不会停止或缓冲视频。

我已经完成了提要部分中的视频播放（在表格视图单元格中），但现在我被困在如何将视频平滑地转换为点击时的视图控制器。

在高层次上，我需要在这里做什么？

我当前的设置有一个AVPlayer 实例作为每个表格视图单元格的一部分。我会将AVPlayer 实例传递给视图控制器并继续从那里播放视频吗？内存管理呢？我觉得每个表格视图单元格都有一个AVPlayer 实例会导致一些问题，但我不完全确定。

作为第二个问题，如果我想忽略花哨的动画/过渡，当在表格视图单元格中点击视频时，如何继续在视图控制器中无缝播放视频？

【参考方案1】：

要从视频单元格转换到播放器控制器，您可以使用 AVPlayerLayer 和自定义动画，例如：

ViewController.swift

// Present player controller
let playerViewController = AVPlayerViewController()
playerViewController.player = player // Your current player instance
playerViewController.transitioningDelegate = self // Custom animation
        
self.present(playerViewController, animated: true, completion: nil)

extension ViewController: UIViewControllerTransitioningDelegate 
  func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? 
    return PlayerAnimationController(playerLayer: playerLayer) // Your current player's layer
  

PlayerAnimationController.swift

class PlayerAnimationController: NSObject, UIViewControllerAnimatedTransitioning 
    
    let playerLayer: AVPlayerLayer
    
    init(playerLayer: AVPlayerLayer) 
        self.playerLayer = playerLayer
    
    
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval 
        return 0.5
    
    
    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) 
        guard let toView = transitionContext.view(forKey: .to) else  return 
        
        let containerView = transitionContext.containerView
        containerView.addSubview(toView)
        
        let originalSuperlayer = playerLayer.superlayer
        let originalFrame = playerLayer.frame
        
        let frame = playerLayer.convert(playerLayer.bounds, to: nil)
        containerView.layer.addSublayer(self.playerLayer)
        
        // Start frame
        CATransaction.begin()
        CATransaction.setAnimationDuration(0)
        CATransaction.setDisableActions(true)
        
        self.playerLayer.frame = frame
        
        CATransaction.commit()
        
        toView.alpha = 0
        
        DispatchQueue.main.async 
            let duration = self.transitionDuration(using: transitionContext)
            UIView.animateKeyframes(withDuration: duration, delay: 0) 
                UIView.addKeyframe(withRelativeStartTime: 0, relativeDuration: 1/2) 
                    self.playerLayer.frame = containerView.bounds
                
                
                UIView.addKeyframe(withRelativeStartTime: 1/2, relativeDuration: 1/2) 
                    toView.alpha = 1.0
                
            
            completion:  _ in
                originalSuperlayer?.addSublayer(self.playerLayer)
                self.playerLayer.frame = originalFrame
                
                transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
            
        
       

示例使用AVPlayerViewController，但您当然可以使用自己的。