Question

This is a long standing issue for me, which I’ve been unable to solve.
I’m trying to play a sequence of small audio files. However I get a memory leak if I don’t release the AVAudioPlayer, if I do release it the file doesn’t play at all.

I’ve tried autorelease, but nothing works.

- (void) playSoundShowLabel:(NSTimer*)theTimer {

    NSMutableDictionary *dict = [[[NSMutableDictionary alloc] 
         initWithDictionary:[theTimer userInfo]] autorelease];

    NSURL *clickURL = [NSURL fileURLWithPath:[NSString 
         stringWithFormat:@"%@/%@.mp3", [[NSBundle mainBundle] resourcePath], 
         [dict valueForKey:@"sWav"]]];  

    AVAudioPlayer *theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL:
         clickURL error:nil];

    [theAudio play];
    theAudio.numberOfLoops = 0;
    //[theAudio release]; << stops play
}

I have tried other ways to play files with system sound but I get other problems with this, so I do need to use AVAudioPlayer.

I have googled this but not found an answer 🙁

Answer 1

Use an instance variable for the player and make sure it stays valid until the audio is done or should be aborted.

For the former, use its delegate – for the latter, use viewDidUnload or dealloc.

For now, I am assuming that you are not using ARC…

Within your interface declaration:

@interface HoldingThePlayerSomeViewController : UIViewController <AVAudioPlayerDelegate>
{
    AVAudioPlayer *theAudio;
}

Within your class implementation:

- (void) playSoundShowLabel:(NSTimer*)theTimer 
{
    NSMutableDictionary *dict = [[[NSMutableDictionary alloc] 
         initWithDictionary:[theTimer userInfo]] autorelease];

    NSURL *clickURL = [NSURL fileURLWithPath:[NSString 
         stringWithFormat:@"%@/%@.mp3", [[NSBundle mainBundle] resourcePath], 
         [dict valueForKey:@"sWav"]]];  

    [theAudio release];
    theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL:
         clickURL error:nil];
    theAudio.delegate = self;

    [theAudio play];
    theAudio.numberOfLoops = 0;
}

- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
    if (player == theAudio)
    {
        [theAudio release];
        theAudio = nil;
    }
}

- (void)dealloc
{
    [theAudio release];
    [super dealloc];
}