向玩家添加观察者时出错

Question

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'An instance 0x1702076f0 of class AVPlayerItem was deallocated while key value observers were still registered with it. Current observation info: (

(.<)NSKeyValueObservance 0x174846360: Observer: 0x174846210, Key path: loadedTimeRanges, Options: Context: 0x0, Property: 0x1748462d0> )'

这是我在将 currentItem.loadedTimeRanges 观察器添加到我的 AVPlayer

后收到的错误

player = AVPlayer(url: videoUrl!)
        playerLayer = AVPlayerLayer(player: player)
        playerLayer.frame = postVideoView.frame
        playerLayer.frame.size.width = UIScreen.main.bounds.width
        self.postVideoView.layer.addSublayer(playerLayer)
        player?.play()
        player?.addObserver(self, forKeyPath: "currentItem.loadedTimeRanges", options: .new, context: nil)
        NotificationCenter.default.addObserver(forName: .AVPlayerItemDidPlayToEndTime, object: self.player?.currentItem, queue: nil, using: { (_) in
            DispatchQueue.main.async {
                self.player?.seek(to: kCMTimeZero)
                self.player?.play()
            }
        })
    }


override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {

    //this is when the player is ready and rendering frames
    if keyPath == "currentItem.loadedTimeRanges" {
        if let duration = player?.currentItem?.duration {
            let seconds = CMTimeGetSeconds(duration)

            let secondsText = Int(seconds) % 60
            let minutesText = String(format: "%02d", Int(seconds) / 60)
            videoLengthLabel.text = "\(minutesText):\(secondsText)"
        }
    }
}

Answer 1

你在哪里打电话给removeObserver？目前看起来，如果您的顶级代码创建了一个新玩家并添加了一个观察者。如果这被调用两次，第一个实例中的观察者将仍然存在。因此，我希望顶部有以下行：

self.player?.removeObserver(self)

如果它没有被调用两次，代码中是否还有其他地方 self.player 被重新分配或解除分配？如果是这样，您应该首先调用 removeObserver.

您还每次向 NotificationCenter 添加一个新的观察者。这应该只被调用一次或 removeObserver 在添加另一个之前。

Answer 2

您需要确保没有多次添加和删除观察者。所以最好的方法就是声明一个 bool 变量让我们说 var isObserverAdded = false.

添加观察者时检查此标志，如果未添加

if !isObserverAdded {
//Add your observer
isObserverAdded = true//Set this to true
}

删除观察者时检查标志是否已添加

if isObserverAdded {
//Add your observer
isObserverAdded = false//Set this to false
}

如果使用上面的检查，你将永远不会得到错误。

向玩家添加观察者时出错

Error while adding an observer to a player

ios

swift

xcode

avplayer