多次按下按钮时声音重叠

Question

当我按下一个按钮，然后再按下另一个按钮时，声音会重叠。我该如何解决这个问题，以便在按下另一个声音时停止第一个声音？

 - (void)playOnce:(NSString *)aSound {

NSString *path = [[NSBundle mainBundle] pathForResource:aSound ofType:@"caf"];
AVAudioPlayer* theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];
[theAudio setDelegate: self];
[theAudio setNumberOfLoops:0];
[theAudio setVolume:1.0];
[theAudio play];    
 }

- (void)playLooped:(NSString *)aSound {

NSString *path = [[NSBundle mainBundle] pathForResource:aSound ofType:@"caf"];
AVAudioPlayer* theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];
[theAudio setDelegate: self];
// loop indefinitely
[theAudio setNumberOfLoops:-1];
[theAudio setVolume:1.0];
[theAudio play];
[theAudio release];


    }

Answer 1

在 viewController 的标题中声明您的 AVAudioPlayer（不要在每次播放声音时分配一个新的）。这样，您将拥有一个可以在 StopAudio 方法中使用的指针。

@interface myViewController : UIViewController <AVAudioPlayerDelegate> { 
    AVAudioPlayer *theAudio;
}
@property (nonatomic, retain) AVAudioPlayer *theAudio;
@end


@implementation myViewController
@synthesize theAudio;
- (void)dealloc {
    [theAudio release];
}
@end



- (void)playOnce:(NSString *)aSound {
    NSString *path = [[NSBundle mainBundle] pathForResource:aSound ofType:@"caf"];
    if(!theAudio){
        theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL: [NSURL fileURLWithPath:path] error:NULL];
    }
    [theAudio setDelegate: self];
    [theAudio setNumberOfLoops:0];
    [theAudio setVolume:1.0];
    [theAudio play];
}

- (void)playLooped:(NSString *)aSound {
    NSString *path = [[NSBundle mainBundle] pathForResource:aSound ofType:@"caf"];
    if(!theAudio){
        theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL: [NSURL fileURLWithPath:path] error:NULL];
    }
    [theAudio setDelegate: self];
    // loop indefinitely
    [theAudio setNumberOfLoops:-1];
    [theAudio setVolume:1.0];
    [theAudio play];
}

- (void)stopAudio {
    [theAudio stop];
    [theAudio setCurrentTime:0];
}

也请务必阅读Apple Docs

Answer 2

您发布的代码只会播放一个声音，即发送到方法的第一个声音。

如果您只想播放一种可变声音，请在停止播放器后，释放音频，然后设置新声音。

Answer 3

在每个方法的开头添加一个检查以查看播放器是否已经在播放：

if (theAudio.playing == YES) {
    [theAudio stop];
}

AVAudioPlayer Class Reference

Answer 4

在您的 playOnce 方法中，“路径”变量未使用 - 删除它以消除您的警告消息。你的 playOnce 没有设置任何要播放的东西，所以我不确定它应该如何工作——除非你先调用 playLooped？您还需要在 initWithContentsOfUrl 之后调用 prepareToPlay。

 - (void)playOnce:(NSString *)aSound {

  NSString *path = [[NSBundle mainBundle] pathForResource:aSound ofType:@"caf"];
  if (theAudio && [theAudio isPlaying]) {
    [theAudio stop]
  } else {
         theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL: [NSURL fileURLWithPath: path] error: NULL];
         [theAudio prepareToPlay];

         [theAudio setDelegate: self];
    [theAudio setNumberOfLoops: 1];
    [theAudio setVolume: 1.0];
    [theAudio play];
  }

}

Answer 5

您需要使用 BOOL 值才能使其正常工作。

在 @implementation 之前的 .m 文件中输入：

static BOOL soundIsPlaying = NO;

那么您的 IBAction 需要看起来像这样：

- (IBAction)play {
    if (soundIsPlaying == YES) {
        [theAudio release];
        soundIsPlaying = NO;

    }

    else if (soundIsPlaying == NO) {
        NSString *path = [[NSBundle mainBundle] pathForResource:@"SOUNDFILENAME" ofType:@"wav"];
        theAudio=[[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];
        theAudio.delegate = self;
        theAudio.volume = 1.0;
        theAudio.numberOfLoops = 0;
        [theAudio play];
        soundIsPlaying = YES;

    }   
}

说实话。当按下另一个按钮时它会停止声音。

Answer 6

您可能可以执行以下操作：

    (void) playLooped: (NSString * ) aSound {
        NSString * path = [[NSBundle mainBundle] pathForResource: aSound ofType: @"caf"];

    //stop audio player from playing so the sound don't overlap
    if([theAudio isPlaying])
    {
        [theAudio stop]; //try this instead of stopAudio

    }

    if (!theAudio) {
        theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL: [NSURL fileURLWithPath: path] error: NULL];
    } 
    [theAudio setDelegate: self];
    // loop indefinitely
    [theAudio setNumberOfLoops: -1];
    [theAudio setVolume: 1.0];
    [theAudio play];
}