AVPlayer状态观察失败时不呼叫

我的应用程序中有一个AVPlayer:

AVAsset *newAsset = [[AVURLAsset alloc] initWithURL:url options:nil];
AVPlayerItem *newPlayerItem = [[AVPlayerItem alloc] initWithAsset:newAsset];

audioPlayer = [[AVPlayer alloc] initWithPlayerItem:newPlayerItem];
[audioPlayer addObserver:self forKeyPath:@"status" options:0 context:nil];
audioPlayer.automaticallyWaitsToMinimizeStalling = NO;

avPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:audioPlayer];
[NowPlayingManager setPlayerLayer:avPlayerLayer];

有时视频无法开始播放,所以我将状态观察添加到 AVPlayer :

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object
                    change:(NSDictionary *)change context:(void *)context {
if (object == audioPlayer && [keyPath isEqualToString:@"status"]) {
    if (audioPlayer.status == AVPlayerStatusReadyToPlay) {
        [avPlayerLayer.player play];
    } else if (audioPlayer.status == AVPlayerStatusFailed) {
        [self playSong];
    } else {
        int i =0;
        i++;
    }
}
}