AVPlayerItemDidPlayToEndTime永远不会到达Swift 3上的选择器

我正在调整我的应用程序到 Swift 3,我遇到了这个问题.这曾经在Swift 2.2上运行,但现在已经坏了. moviePlayBackFinished永远不会被调用.我尝试以多种方式添加观察者,但都没有成功.

NotificationCenter.default.addObserver(self, selector: #selector(self.moviePlayBackFinished(_:)),
                                           name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: player.currentItem);

    NotificationCenter.default.addObserver(self, selector: #selector(moviePlayBackFinished(_:)),
                                           name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: player.currentItem);

    NotificationCenter.default.addObserver(self, selector: #selector(self.moviePlayBackFinished(sender:)),
                                           name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: player.currentItem);

// (...)

@objc func moviePlayBackFinished(sender : AnyObject) {
    print("playbackFinished");
    let zeroCM : CMTime = CMTime(seconds: 0, preferredTimescale: 1000000000);
    playerLayer.player?.seek(to: zeroCM);
}

@objc func moviePlayBackFinished(_ notification: Notification) {
    print("playbackFinished");
    let zeroCM : CMTime = CMTime(seconds: 0, preferredTimescale: 1000000000);
    playerLayer.player?.seek(to: zeroCM);
}

任何想法都会受到关注.

谢谢

这个问题有多种可能的原因.

NotificationCenter
    .default
    .addObserver(self, 
                 selector: #selector(self.moviePlayBackFinished(sender:)),
                 name: .AVPlayerItemDidPlayToEndTime,
                 object: player.currentItem)

首先,您必须将对象设置为nil. AVPlayerItemDidPlayToEndTime通知自动将对象设置为最后到达的AVPlayerItem.如果您手动更改它,您将不会收到任何AVPlayerItemDidPlayToEndTime的通知.

其次,根据AVPlayerItemDidPlayToEndTime文档：

Important

This notification may be posted on a different thread than the one on which the observer was registered.

因此,要确保您应该检查通知是否在您想要的主题上.

你从UIViewController或AVPlayer子类添加观察者并不重要.