Question

I have one problem with my iOS Application. I want to play multiple audio files (.WAV) using IBAction and AVAudioPlayer. Unfortunatelly the sound plays but if I play the sound many times, my application crashes. Maybe because memory is not properly released. Can you confirm my hypothesis and/or tell me how to fix this problem?

Here’s my code.

ViewController.h

#import <UIKit/UIKit.h>
#import <AVFoundation/AVAudioPlayer.h>

@interface ViewController : UIViewController
{
    NSString        *Path;
}

- (IBAction)Sound1;
- (IBAction)Sound2;
- (IBAction)Sound3;
- (IBAction)Sound4;

@end

ViewController.m

#import <AVFoundation/AVAudioPlayer.h>
#import "ViewController.h"

@implementation ViewController

- (IBAction)Sound1
{
    Path = [[NSBundle mainBundle] pathForResource:@"Sound1" ofType:@"wav"];
    Media = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:Path] error:NULL];
    [Media play];
}

- (IBAction)Sound2
{
    Path = [[NSBundle mainBundle] pathForResource:@"Sound2" ofType:@"wav"];
    Media = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:Path] error:NULL];
    [Media play];
}

- (IBAction)Sound3
{
    Path = [[NSBundle mainBundle] pathForResource:@"Sound3" ofType:@"wav"];
    Media = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:Path] error:NULL];
    [Media play];
}

- (IBAction)Sound4
{
    Path = [[NSBundle mainBundle] pathForResource:@"Sound4" ofType:@"wav"];
    Media = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:Path] error:NULL];
    [Media play];
}

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

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

- (void)viewDidUnload
{
    [super viewDidUnload];
}

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

@end

Answer 1

The problem is that you’re allocating lots of AVAudioPlayer instances, but not releasing any of them.

What you need to do is set up your class as a AVAudioPlayerDelegate, remove the media instance variable from your class (instead simply create a new instance variable within your various IBAction methods) and implement the audioPlayerDidFinishPlaying:successfully: method as follows:

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

Finally, update your code to set your class as the delegate for each of the AVAudioPlayers you set up as follows:

...
Media = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:Path] error:NULL];
[Media setDelegate:self];
[Media play];
...

By doing this, you’ll ensure that you’re releasing all of the AVAudioPlayer instances you create.