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

Question

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

Answer 1

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AVPlayerItem最后到达的对象.如果您手动更改它,您将不会收到任何通知AVPlayerItemDidPlayToEndTime.

第二,根据AVPlayerItemDidPlayToEndTime文件:

重要

该通知可以发布在与观察者注册的线程不同的线程上.

因此,要确保您应该检查通知是否在您想要的主题上.

你添加观察者UIViewController或AVPlayer子类并不重要.