如何在不同的 UICollectionView 单元格中显示不同的视频？

Posted 2023-03-14

【中文标题】如何在不同的 UICollectionView 单元格中显示不同的视频？

【英文标题】：How to show different videos in different UICollectionView cells?

【发布时间】：2019-12-06 21:57:05

【问题描述】：

我试图在五个不同的 UICollectionView 单元格中显示 5 个不同的视频。这听起来很容易做到，并且使用 3 个单元格它工作正常，但现在不知何故所有视频都在错误的单元格中。

这是一个丑陋的解决方案，但它以前有效，我想不出任何其他解决方案。

这是 AVPlayer 和 AVPlayerLayer 的五个不同实例。

    let theURL = Bundle.main.url(forResource:"summer", withExtension: "mp4")
    let theURL2 = Bundle.main.url(forResource:"newyork", withExtension: "mp4")
    let theURL3 = Bundle.main.url(forResource:"amber", withExtension: "mp4")
    let theURL4 = Bundle.main.url(forResource:"luckywhite", withExtension: "mp4")
    let theURL5 = Bundle.main.url(forResource:"coconut", withExtension: "mp4")
    avPlayer = AVPlayer(url: theURL!)
    avPlayerLayer = AVPlayerLayer(player: avPlayer)
    avPlayerLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
    avPlayer.volume = 0
    avPlayer.actionAtItemEnd = .none
    NotificationCenter.default.addObserver(self,
    selector: #selector(playerItemDidReachEnd(notification:)),
    name: NSNotification.Name.AVPlayerItemDidPlayToEndTime,
    object: avPlayer.currentItem)


    avPlayer2 = AVPlayer(url: theURL2!)
    avPlayerLayer2 = AVPlayerLayer(player: avPlayer2)
    avPlayerLayer2.videoGravity = AVLayerVideoGravity.resizeAspectFill
    avPlayer2.volume = 0
    avPlayer2.actionAtItemEnd = .none
    NotificationCenter.default.addObserver(self,
    selector: #selector(playerItemDidReachEnd(notification:)),
    name: NSNotification.Name.AVPlayerItemDidPlayToEndTime,
    object: avPlayer2.currentItem)


    avPlayer3 = AVPlayer(url: theURL3!)
    avPlayerLayer3 = AVPlayerLayer(player: avPlayer3)
    avPlayerLayer3.videoGravity = AVLayerVideoGravity.resizeAspectFill
    avPlayer3.volume = 0
    avPlayer3.actionAtItemEnd = .none
    NotificationCenter.default.addObserver(self,
    selector: #selector(playerItemDidReachEnd(notification:)),
    name: NSNotification.Name.AVPlayerItemDidPlayToEndTime,
    object: avPlayer3.currentItem)

    avPlayer4 = AVPlayer(url: theURL4!)
    avPlayerLayer4 = AVPlayerLayer(player: avPlayer4)
    avPlayerLayer4.videoGravity = AVLayerVideoGravity.resizeAspectFill
    avPlayer4.volume = 0
    avPlayer4.actionAtItemEnd = .none
    NotificationCenter.default.addObserver(self,
    selector: #selector(playerItemDidReachEnd(notification:)),
    name: NSNotification.Name.AVPlayerItemDidPlayToEndTime,
    object: avPlayer4.currentItem)

    avPlayer5 = AVPlayer(url: theURL5!)
    avPlayerLayer5 = AVPlayerLayer(player: avPlayer5)
    avPlayerLayer5.videoGravity = AVLayerVideoGravity.resizeAspectFill
    avPlayer5.volume = 0
    avPlayer5.actionAtItemEnd = .none
    NotificationCenter.default.addObserver(self,
    selector: #selector(playerItemDidReachEnd(notification:)),
    name: NSNotification.Name.AVPlayerItemDidPlayToEndTime,
    object: avPlayer5.currentItem)

我在这里将视频放入单元格中。

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell 
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! CollectionViewCell

    switch indexPath.item 
        case 0:
            self.avPlayerLayer.frame = cell.image.layer.bounds
            cell.image.layer.insertSublayer(self.avPlayerLayer, at: 0)

        case 1:
            self.avPlayerLayer2.frame = cell.image.layer.bounds
            cell.image.layer.insertSublayer(self.avPlayerLayer2, at: 0)

        case 2:
            self.avPlayerLayer3.frame = cell.image.layer.bounds
            cell.image.layer.insertSublayer(self.avPlayerLayer3, at: 0)

        case 3:
            self.avPlayerLayer4.frame = cell.image.layer.bounds
            cell.image.layer.insertSublayer(self.avPlayerLayer4, at: 0)

        default:
            self.avPlayerLayer5.frame = cell.image.layer.bounds
            cell.image.layer.insertSublayer(self.avPlayerLayer5, at: 0)
    

为什么它不能正常工作？我认为在使用 indexPaths 时我做的一切都是正确的。

【参考方案1】：

细胞被重复使用，当你这样做时

 self.avPlayerLayer4.frame = cell.image.layer.bounds
 cell.image.layer.insertSublayer(self.avPlayerLayer4, at: 0)

所以考虑在插入之前清洁它

  cell.image.layer.sublayers?.forEach 
      if $0 is AVPlayerLayer 
          $0.removeFromSuperlayer()
      
   

它最多添加层并显示之前添加的旧层，而不是重复的代码，您需要编写一个从 url 返回层并添加它的函数

---

还可以考虑使用类似的数组

var arr = [URL]()

用它代替开关

【讨论】：

有什么解决方案可以让它发挥作用吗？还是不可能？

它的工作就像魅力一样。我希望它适用于 10-15 个不同的视频。非常感谢您，先生！