如何停止按钮重叠？

Question

  

可能重复：
  Sound stop playing
  iPhone - Sound overlapping with multiple button presses

@interface Cars: UIViewController < AVAudioPlayerDelegate >
{
    AVAudioPlayer * theAudio;
}

@property(nonatomic, retain) AVAudioPlayer * theAudio;

(void) playOnce: (NSString * ) aSound;
(void) playLooped: (NSString * ) aSound;

@implementation Cars

@synthesize theAudio;

(void) dealloc {
    [theAudio release];
}

(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];
}

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

如何停止按钮重叠？