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检测AVQueuePlayer中的当前项目并知道它何时更改?

avqueueplayer nsnotifications avplayer avaudioplayer ios

3

KingPolygon · 技术社区 · 11 年前

我现在有一个AVQueuePlayer,按顺序播放一些.aif文件。当它通过每个音频时,我想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。我已经将其设置为当队列完成最后一个对象时通知我,但我很难接收到每个当前项目的通知。以下是我所拥有的:

//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];

我觉得我被name参数卡住了。我应该把它改成什么?当它切换时,我该如何找到当前正在播放的播放器项目的名称?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];


    }


}

2 回复 | 直到 11 年前

1

3

BhushanVU 11 年前

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

2

Pantelis Proios 9 年前

Bhushan的回答缺少触发每个项目通知的循环,因此:

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