iphone - viewDidUnload-更改 View 时停止方法

Question

我希望在更改 View 时停止播放音频文件。

我正在使用tabController，并且我希望当用户移至其他 View 时停止播放的音频。我不确定该在哪里以及如何进行。在viewDidUnload中？

这是我用来播放音频文件的方法:

-(void)startPlaying {
[NSTimercheduledTimerWithTimeInterval:15目标:自我选择器:@selector(startPlaying)userInfo:无重复:NO]；

NSString * audioSoundPath = [[NSBundle mainBundle] pathForResource:@“audio_file” ofType:@“caf”]；
CFURLRef audioURL =(CFURLRef)[NSURL fileURLWithPath:audioSoundPath];
AudioServicesCreateSystemSoundID(audioURL，＆audioID);
AudioServicesPlaySystemSound(audioID);
}

谢谢你的帮助

Answer 1

在您的 View Controller 中这样的东西(未经测试):

- (void)viewDidLoad
{
    [super viewDidLoad];

    // Load sample
    NSString *audioSoundPath = [[NSBundle mainBundle] pathForResource:@"audio_file"
                                                                ofType:@"caf"];
    CFURLRef audioURL = (CFURLRef)[NSURL fileURLWithPath:audioSoundPath];
    AudioServicesCreateSystemSoundID(audioURL, &audioID)
}

- (void)viewDidUnload
{
    // Dispose sample when view is unloaded
    AudioServicesDisposeSystemSoundID(audioID);

    [super viewDidUnload];
}

// Lets play when view is visible (could also be changed to viewWillAppear:)
- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    [self startPlaying];
}

// Stop audio when view is gone (could also be changed to viewDidDisappear:)
- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];

    if([self.audioTimer isValid]) {
        [self.audioTimer invalidate];
    }
    self.timer = nil;
}

// Start playing sound and reschedule in 15 seconds.
-(void)startPlaying
{
    self.audioTimer = [NSTimer scheduledTimerWithTimeInterval:15 target:self   
                                                     selector:@selector(startPlaying)
                                                     userInfo:nil
                                                      repeats:NO];
    AudioServicesPlaySystemSound(audioID);
}

失踪:

检查

错误

audioTimer的属性或ivar。

也可以保留相同的计时器，重复YES。

释放dealloc中的资源。

测试