在AVQueuePlayer中检测当前项目并知道它何时更改？

我目前有一个AVQueuePlayer按顺序播放几个.aif文件。 当它通过每个audio时，我想要执行与特定声音相关的操作（例如，更改imageview的uiimage）。

我的问题是正确设置NSNotification。 我已经设置它通知我，当队列完成最后一个对象，但我无法收到每个当前项目的通知。 这是我有什么：

//Setting Up My Queue List yellowVoice = [[AVPlayerItem alloc] initWithURL:[NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/YellowVoice.aif", [[NSBundle mainBundle] resourcePath]]]]; orangeVoice = [[AVPlayerItem alloc] initWithURL:[NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/OrangeVoice.aif", [[NSBundle mainBundle] resourcePath]]]]; redVoice = [[AVPlayerItem alloc] initWithURL:[NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/RedVoice.aif", [[NSBundle mainBundle] resourcePath]]]]; pinkVoice = [[AVPlayerItem alloc] initWithURL:[NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/PinkVoice.aif", [[NSBundle mainBundle] resourcePath]]]]; NSArray *soundEmotions = [NSArray arrayWithObjects:yellowVoice, orangeVoice, redVoice, pinkVoice, nil]; soundQueue = [AVQueuePlayer queuePlayerWithItems:soundEmotions]; // Notify me when queue reaches the end of the last player item [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(playerItemDidReachEnd:) name:AVPlayerItemDidPlayToEndTimeNotification object:[soundEmotions lastObject]]; // Notify me when a new player item begins and which one it is [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(currentItemIs:) name:AVPlayerItemDidPlayToEndTimeNotification object:[soundQueue currentItem]]; [soundQueue play]; 

我觉得我卡在名称参数。 我应该改变什么？ 我怎样才能find当前正在播放的播放器的名称，因为它切换？ 谢谢！

 //Here is one of the things I want to do with that info - (void)currentItemIs:(NSNotification *)notification { if (soundQueue.currentItem ==yellowVoice) { UIImage * yellowImage = [UIImage imageNamed:@"yellow.png"]; [UIView transitionWithView:self.view duration:1.0f options:UIViewAnimationOptionTransitionCrossDissolve animations:^{ mainImage.image = yellowImage; } completion:NULL]; } if (soundQueue.currentItem ==yellowVoice) { UIImage * orangeImage = [UIImage imageNamed:@"orange.png"]; [UIView transitionWithView:self.view duration:1.0f options:UIViewAnimationOptionTransitionCrossDissolve animations:^{ mainImage.image = orangeImage; } completion:NULL]; } } 

Answer 1

 - (void)currentItemIs:(NSNotification *)notification { AVPlayerItem *p = [notification object]; if (p ==yellowVoice) { //rest of the code } } 

Answer 2

Bhushan的答案是缺less循环触发每个项目的通知，所以：

 for (AVPlayerItem *playerItem in queuePlayer.items) { [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(currentItemIs:) name:AVPlayerItemDidPlayToEndTimeNotification object:playerItem]; }