iphone – iOS SDK：在后台播放音乐和切换视图

我正在尝试在我的应用程序中播放音乐.音乐工作正常,但在切换viewControllers并返回主菜单后,我的音乐再次播放！这意味着几个相同的声音一起播放！我怎么解决这个问题？这是我的代码：

- (void)viewDidLoad {

    Nsstring *music = [[NSBundle mainBundle] pathForResource:@"1music" ofType:@"mp3"];
    myMusic = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:music] error:NULL];
    myMusic.delegate = self;
    myMusic.numberOfLoops = -1; 
    [myMusic play];
}


- (IBAction) scoreView {

    scoreViewController *scoreView = [[scoreViewController alloc] initWithNibName:@"scoreViewController" bundle:nil];
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:1];
    [UIView setAnimationTransition:UIViewAnimationTransitionCurlDown forView:self.view cache:YES];
    [self.view addSubview: scoreView.view];
    [UIView commitAnimations];
}

编辑代码：

- (id)initWithNibName:(Nsstring *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
        if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) {

            Nsstring * musicSonati = [[NSBundle mainBundle] pathForResource:@"music" ofType:@"mp3"];
            myMusic = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:musicSonati] error:NULL];
            myMusic.delegate = self;
            myMusic.numberOfLoops = -1;
            [myMusic play];

        }
        return self;
    }

//toggle button
- (IBAction)MusicPlaying:(id)sender {

    if ((isPlay = !isPlay))
    {

        UIImage *buttonImagenormal = [UIImage imageNamed:@"play.png"]; 
        UIImage *stretchableButtonImagenormal = [buttonImagenormal  stretchableImageWithLeftCapWidth:0 topCapHeight:0]; 
        [MusicButton setBackgroundImage:stretchableButtonImagenormal forState:UIControlStatenormal]; 
        [myMusic pause];



    }else {

        UIImage *buttonImagenormal = [UIImage imageNamed:@"pause.png"]; 
        UIImage *stretchableButtonImagenormal = [buttonImagenormal  stretchableImageWithLeftCapWidth:0 topCapHeight:0]; 
        [MusicButton setBackgroundImage:stretchableButtonImagenormal forState:UIControlStatenormal]; 
        NSLog(@"Music play");
        [myMusic play];

    } 

}

解决方法

确保myMusic被正确声明为保留属性并合成然后尝试这样的事情：

-(void) commonInit {
    Nsstring * musicSonati = [[NSBundle mainBundle] pathForResource:@"music" ofType:@"mp3"];
    self.myMusic = [[[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:musicSonati] error:NULL] autorelease];
    self.myMusic.delegate = self;
    self.myMusic.numberOfLoops = -1;
//You probably don't want to play music on init,rather defer to viewDidLoad.
//        [self.myMusic play];
}

- (id)initWithCoder:(NSCoder *)coder {
    self = [super initWithCoder:coder];
    if (self) {
        [self commonInit];
    }
    return self;
}

- (id)init {
    self = [super init];
    if (self) {
        [self commonInit];
    }
    return self;
}

- (id)initWithNibName:(Nsstring *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) {
        [self commonInit];
    }
    return self;
}

然后在viewDidLoad中尝试：

- (void)viewDidLoad {
    ...
    if (!self.myMusic.playing) {
        [self.myMusic play];
    }
    ...
}

另外,不要忘记以dealloc发布你的播放器！