Is there any way i can group three classes?

What I want to do is I have many classes first of all, they all have the same music throughout, as i said in the app delegates bool application did finish launching method. But in my last 3 classes, I want different music, fair enough, I put these lines of code:

 [(Smart2AppDelegate *)[UIApplication sharedApplication].delegate pauseAudioPlayer];
[(Smart2AppDelegate *)[UIApplication sharedApplication].delegate newAudioPlayer];

And in my app delegate:

 -(void)newAudioPlayer {

NSString *music = [[NSBundle mainBundle]
                   pathForResource:@"win" ofType:@"m4a"];
audio.delegate = self;
self.audio = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:music] error:NULL];

[audio play];
audio.numberOfLoops = -1;
     }

 -(void)paus开发者_运维问答eAudioPlayer {

[audio pause];
 }

So it works, whenever I go to that view, it changes music, lets call that view, view x. Now, from that view x I can go to and from only to 2 other views, e.g. I can go to the info page and there is a back button that leads back to that view x, and the same with a prize page. But when I go back to the view x, the music starts from the beginning, when in these three classes, i want them to all loop and not go from beginning because it sounds akward. The reason is simple it is because I put it in the viewDidLoad. But how can I do this, I was thinking of a way to actually group classes and put in the avaudioplayer method in there.

Here you have a possible approach:

1. Refactor out the music+sounds mechanisms into a separate class, i.e. something like Smart2AudioPlayer.
2. Public the necessary methods: play, pause, resume so you can use the audio player from anywhere.
3. In each viewDidLoad method, call the audio player and pass along a parameter to indicate who is the sender (who wants the sound to be played) and a preference indicating whether you wish to continue playing the current group song (see bellow) or start it all over again.
4. Implement the necessary logic in your audio player to allow certain groups of classes to be associated together. This way, when you are playing a song from a class that belongs to a group, and another class of the same group asks for the music to be played, you won't start the song again, you simply do nothing.

Hope this helps