Question

我希望在更改视图时停止播放音频文件。

我正在使用tabController，我希望当用户移动到不同的视图时播放的音频停止。我不知道我会在哪里以及如何做到这一点。在viewDidUnload中也许？

这是我用来播放音频文件的方法：

- （void）startPlaying { [NSTimer scheduledTimerWithTimeInterval：15 target：self selector：@selector（startPlaying）userInfo：nil repeats：NO];

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

感谢您的帮助

Answer 1

你的视图控制器中有类似的东西（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);
}

缺失：

检查错误
属性或ivar for audioTimer。
也可以保留相同的计时器，重复是。
释放dealloc中的资源。
测试

viewDidUnload - 在视图更改时停止方法

1 个答案: