带参数的 NSNotificationCenter

Question

我正在实现一个基于音频的应用程序。我使用两个 AVPlayer 播放两种不同的声音。声音播放后我需要执行不同的操作。为此我使用了 NSNotifications。但我的问题是我无法找到与哪个玩家相关的通知。我的通知代码和选择器代码如下，请任何人告诉我我犯了什么错误。

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(playingItemDidEnd:)
                                             name:AVPlayerItemDidPlayToEndTimeNotification
                                           object:iPodPlayer]; 


[[NSNotificationCenter defaultCenter] addObserver:self
                                       selector:@selector(playingItemDidEnd:)
                                             name:AVPlayerItemDidPlayToEndTimeNotification
                                           object:applicationPlayer ];

- (void)playingItemDidEnd:(NSNotification *)notification 
{
      id object= [notification object];

     if(object==ipodPlayer)
     {
       printf("\n Notification from iPod Player ");

     }
     else if(object==applicationPlayer)
     {
       printf("\n Notification from application Player ");
     }

}

提前致谢， 钱德拉。

Answer 1

我需要更改代码库如下，

   [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(playingItemDidEnd:)
                                             name:AVPlayerItemDidPlayToEndTimeNotification
                                           object:[applicationPlayer currentItem] ];

   [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(playingItemDidEnd:)
                                             name:AVPlayerItemDidPlayToEndTimeNotification
                                           object:[iPodPlayer currentItem]];

选择器代码应如下，

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

    AVPlayerItem* object= [notification object];
    if(object==[applicationPlayer currentItem])
    {

    }
    else if(object==[avPlayer currentItem])
    {

    }
}