ios - MPMoviePlayerController 在 play() 时被释放 - swift

Question

我正在尝试将 MPMoviePlayerController 添加到 View Controller ，但它在 play() 调用时被释放。该 URL 在打印时有效，我也在不同的 viewController 中使用了几乎相同的代码，并且它工作得很好。 View Controller 之间的唯一区别是这个 View Controller 是从不同的 viewController 中分离出来的。我一直在为此绞尽脑汁，并尝试了我可以在此处找到的所有类似解决方案，因此非常感谢任何帮助。

为 Segue 做准备

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "ShowChannel" {
        if let destination = segue.destinationViewController as? ShowChannelController {
            destination.channelId = channelId
            destination.postsCollection = postsCollection
        }
    }
}

MPMoviePlayerController代码

var newMoviePlayer: MPMoviePlayerController!
var postsCollection = [Post]()
var videoPosition = 0
var channelId: String = ""

override func viewDidLoad() {
    super.viewDidLoad()
    
    startPlayingVideo(videoPosition)
    updateNowPlaying(videoPosition)
    
} 

func videoHasFinishedPlaying(notification: NSNotification) {
    /* Find out what the reason was for the player to stop */
    let reason =
    notification.userInfo![MPMoviePlayerPlaybackDidFinishReasonUserInfoKey]
        as! NSNumber?
    if let theReason = reason{
        
        let reasonValue = MPMovieFinishReason(rawValue: theReason.integerValue)

        stopPlayingVideo()
        
        switch reasonValue!{
        case .PlaybackEnded:
            if (videoPosition < self.postsCollection.count - 1) {
                videoPosition++
            } else {
                videoPosition = 0
            }
            startPlayingVideo(videoPosition)
            let rowToSelect:NSIndexPath = NSIndexPath(forRow: videoPosition, inSection: 0);
            self.tableView.selectRowAtIndexPath(rowToSelect, animated: true, scrollPosition: UITableViewScrollPosition.None);
            updateNowPlaying(videoPosition)
            
        case .PlaybackError:
            /* An error happened and the movie ended */
            print("Error happened")
        case .UserExited:
            /* The user exited the player */
            print("User exited")
        }
        
    }
    
}

/** What to do when we stop playing a video */
func stopPlayingVideo() {
    if let player = self.newMoviePlayer {
        NSNotificationCenter.defaultCenter().removeObserver(self)
        player.stop()
        player.view.removeFromSuperview()
    }
    
}

/** Initializes and starts the video player */
func startPlayingVideo(index: Int) {
    let url: NSURL = NSURL(string: postsCollection[index].url)!
    print(postsCollection[index].url)
    self.newMoviePlayer = MPMoviePlayerController(contentURL: url)

    if let player = self.newMoviePlayer {
        
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "videoHasFinishedPlaying:", name: MPMoviePlayerPlaybackDidFinishNotification, object: nil)
        
        player.view.frame = CGRect(x: 0, y: ((self.view.bounds.size.height * 0.45) - (self.view.bounds.size.height / 3)), width: self.view.bounds.size.width, height: self.view.bounds.size.height / 3)
        
        self.view.addSubview(player.view)
        player.prepareToPlay()
        player.play()
        player.controlStyle = MPMovieControlStyle.Embedded
        
    } else {
        print("Failed to instantiate the movie player")
    }
    
}

错误:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[OS_xpc_dictionary _postNotificationName:object:userInfo:]: unrecognized selector sent to instance 0x17ed2240'

启用僵尸:

-[MPMoviePlayerControllerNew _postNotificationName:object:userInfo:]: message sent to deallocated instance 0x17f47400**

Answer 1

终于意识到我的错误:

提到的第一个 ViewController 具有类似的实现，并且工作正常，但没有正确处理“NotificationCenter”，两个独立类中的观察者感到困惑。

解决方案:

在第一个 ViewController 的 viewDidDisappear() 中移除观察者

FirstViewController.swift

override func viewDidDisappear(animated: Bool) {
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

经验教训:不要忘记注销自己!