淡入時，MPMoviePlayerController有時播放音頻，而不播放視頻

Question

我有一個問題，在UIScrollView中，有許多視圖（下面的視頻控制器）充當視頻內容的頁面（最初顯示了縮略圖視圖）。

有時（但並非總是），當我滾動到下一頁時，視頻的音頻開始播放，但看不到任何視覺效果。 當我不淡入視圖時，似乎不會發生這種情況。

視頻初始化代碼為：

  MPMoviePlayerController* moviePlayer = [[MPMoviePlayerController alloc] init];

  self.moviePlayer = moviePlayer;

  [moviePlayer setControlStyle:MPMovieControlStyleNone];
  [moviePlayer setRepeatMode:MPMovieRepeatModeOne];
  [moviePlayer.view setFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];

  moviePlayer.backgroundView.backgroundColor = [UIColor clearColor];
  moviePlayer.movieSourceType = MPMovieSourceTypeStreaming;
  moviePlayer.contentURL = [NSURL URLWithString:[videoData.video src]];

  [self.videoController.view addSubview:self.moviePlayer.view];
  [self.videoController.view bringSubviewToFront:moviePlayer.view];
  [moviePlayer.view setAlpha:0.0f];

  // Movie Observer
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(checkMovieStatus:) name:MPMoviePlayerLoadStateDidChangeNotification object:nil];

  // Add tap handler
  UITapGestureRecognizer *singleFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(onPlayerTapped:)];
  singleFingerTap.numberOfTapsRequired = 1;
  singleFingerTap.delegate = self;
  [self.moviePlayer.view addGestureRecognizer:singleFingerTap];

  [moviePlayer prepareToPlay];

播放代碼（為避免在視頻開始時出現黑屏）是：

- (void)checkMovieStatus:(NSNotification *)notification {
    if(self.moviePlayer.readyForDisplay && (MPMovieLoadStatePlayable | MPMovieLoadStatePlaythroughOK)) {

          [self.moviePlayer play];

          [[NSNotificationCenter defaultCenter] removeObserver:self name:MPMoviePlayerLoadStateDidChangeNotification object:nil];

          [UIView animateWithDuration:0.4f animations:^{
              [self.moviePlayer.view setAlpha:1.0f];
          } completion:^(BOOL finished) {
              //[self.moviePlayer play]; // tried here as well
          }];
        }
}

刪除滾動上的視頻視圖的代碼是：

- (void)removeMoviePlayer {
        if(self.moviePlayer) {
                [self.moviePlayer stop];

                [self.moviePlayer.view removeFromSuperview];

                self.moviePlayer = nil;
        }
}

Answer 1

我發現此問題的解決方法很奇怪。 以我為例，我將滑動至視頻，然后播放音頻，並且沒有圖片。 如果我輕掃一下再回來，一切都很好，所以只是為了好玩，我嘗試了

MPMoviePlayerController *mp = [self.arrayOfScrollView objectAtIndex:xx];
[mp play];
[mp stop];
[mp play];

奇怪的是。 自從您六個月前發布此文章以來，如果您發現了另一個解決方法，我很想知道。