iOS 7 MPMoviePlayerController 向前搜索按钮将视频带到结束并显示黑屏

Question

我在 iOS 7 中遇到 MPMoviePlayerController 的问题。我进入全屏模式，然后单击（只需单击一下）向前搜索按钮 (>>|) ，视频播放结束并出现带有文本的黑屏标题上的“正在加载”。

我为“MPMoviePlayerPlaybackStateDidChangeNotification”注册了通知。

**[[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(moviePlayerPlaybackStateDidChange:)
                                                 name:MPMoviePlayerPlaybackStateDidChangeNotification
                                               object:self.player];**

单击前进按钮不会触发它。

还有关于“MPMoviePlayerPlaybackDidFinishNotification”的注册

**[[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(moviePlayerPlaybackDidFinish:)
                                                 name:MPMoviePlayerPlaybackDidFinishNotification
                                               object:nil];**

单击“向前搜索”按钮会触发“MPMovieFinishReasonPlaybackEnded”事件。 有谁知道原因吗？这是苹果的bug吗？

我需要停止这种单击时显示黑屏的行为，或者只是禁用单击前进按钮的单击，这样什么都不会发生。

任何人都知道如何实现这一目标？

Answer 1

当您单击快进或快退按钮时，将调用 MPMoviePlayerLoadStateDidChangeNotification。您应该检查 loadState 并为其提供视频的路径并再次 prepareToPlay。

- (void)moviePlayerLoadStateChanged:(NSNotification *)notification {

    MPMoviePlayerController *moviePlayer = notification.object;
    MPMovieLoadState loadState = moviePlayer.loadState;

    if(loadState == MPMovieLoadStateUnknown) {
        moviePlayer.contentURL = [NSURL fileURLWithPath:videoPath]
        [moviePlayer prepareToPlay];
    }

    .....
}

Answer 2

我通过完全删除 MPMoviePlayer 对象、将其设置为 nil、将其从超级视图中删除并使用原始视频 Url 重新添加来解决此问题。代码如下：

- (void)addPlayerForUrl:(NSURL *)url {
  self.player = [[MPMoviePlayerController alloc] initWithContentURL:url];
  self.player.view.frame = self.videoView.bounds;
  self.player.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
  self.player.controlStyle = MPMovieControlStyleDefault;
  [self.videoView insertSubview:self.player.view atIndex:0];

  [[NSNotificationCenter defaultCenter] addObserver:self
                                           selector:@selector(moviePlayerLoadStateDidChangedNotification:)
                                               name:MPMoviePlayerReadyForDisplayDidChangeNotification
                                             object:self.player];

  [[NSNotificationCenter defaultCenter] addObserver:self
                                           selector:@selector(moviePlayerPlaybackStateDidChangeNotification:)
                                               name:MPMoviePlayerPlaybackStateDidChangeNotification
                                             object:self.player];
}


#pragma mark - Notifications

- (void)moviePlayerLoadStateDidChangedNotification:(NSNotification *)notification {
  self.isVideoPreloaded = YES;
  self.videoPlayButton.hidden = YES;
  self.photoImageView.hidden = YES;
  self.videoLoadingImageView.hidden = YES;
}
- (void)moviePlayerPlaybackStateDidChangeNotification:(NSNotification *)notification {
      NSURL *url = self.player.contentURL;
      switch (self.player.playbackState) {
        case MPMoviePlaybackStateSeekingBackward:
        case MPMoviePlaybackStateSeekingForward:
          break;
        case MPMoviePlaybackStatePlaying:
          self.videoPlayButton.hidden = YES;

          if (!self.isVideoPreloaded) {
            self.videoLoadingImageView.hidden = NO;
            [self.videoLoadingImageView startAnimating];
          } else {
            self.videoLoadingImageView.hidden = YES;
          }
          break;
        case MPMoviePlaybackStatePaused:
        case MPMoviePlaybackStateStopped:
          self.videoPlayButton.hidden = NO;
          self.videoLoadingImageView.hidden = YES;
          [self.player endSeeking];
          [self.player.view removeFromSuperview];
          [self.player setFullscreen:NO];
          self.player = nil;
          [self addPlayerForUrl:url];
          break;
        default:
          break;
      }
    }

请注意我是如何在moviePlayerPlaybackStateDidChangeNotification 中的switch 语句之前保留NSURL 的。这样，我可以重新初始化并重新添加 MPMoviePlayer 对象。

顺便说一句，如果您想知道的话，我的 mpmovieplayer 位于 tableviewCell 上。希望这会有所帮助，如果您有任何问题，请告诉我。祝你好运！

Answer 3

您收到 MPMovieFinishReasonPlaybackEnded 的原因是因为播放到了视频的结尾（很抱歉，如果这很明显）。因此，您的前向搜索操作似乎一直在搜索视频的结尾。您可以通过MPMoviePlaybackStateSeekingForward查看播放状态。

一个快速的解决方案可能是创建您自己的前进按钮，该按钮在指定时间（即 5 秒）前搜索。但也许这不是您想要的功能。