檢查音頻是否已經結束播放iOS

Question

我想檢查音頻是否已結束播放。如果是這樣，我需要將按鈕更改爲播放按鈕而不是暫停按鈕。我如何在iOS中執行此操作？

我的代碼如下所示：

-(void)playAudioFile:(BOOL)status 
{ 
    NSString *soundFilePath = [[NSBundle mainBundle] pathForResource:@"audio" ofType:@"mp3"]; 
    NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath]; 


    NSError *error; 

    if(status) 
    { 

     if(!audioPlayer) 
     { 
      audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:soundFileURL error:&error]; 
      audioPlayer.currentTime = currentPlayTime; 
      audioPlayer.numberOfLoops = 0; //Infinite 
      audioDuration = audioPlayer.duration; 

      audioPlaySlider.minimumValue = 0; 
      audioPlaySlider.maximumValue = audioDuration; 
      audioPlaySlider.value = currentPlayTime; 

      [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(audioTimer:) userInfo:[NSDictionary dictionaryWithObject:audioPlayer forKey:@"playerObject"] repeats:YES]; 
     } 

     [audioPlayer play]; 

     if([audioPlayer rate] != 1.0) 
     { 
      [audioPlayer play]; 
     } 
     else 
     { 
      [self->audioPlayBtn setBackgroundImage:[UIImage imageNamed:@"playBtn.png"] forState:UIControlStateNormal]; 
     } 


     NSLog(@"Play duration : %f",audioDuration); 
    } 
    else 
    { 
     if(audioPlayer && audioPlayer.playing) 
     { 
      [audioPlayer pause];     
     } 
    } 

    NSLog(@"Error for file : %@",error); 

} 

我嘗試這樣做：

  if([audioPlayer rate] != 1.0) 
      { 
       [audioPlayer play]; 
      } 
      else 
      { 
       [self->audioPlayBtn setBackgroundImage:[UIImage imageNamed:@"playBtn.png"] forState:UIControlStateNormal]; 
      } 

但沒有工作..需要一些指導...

Answer 1

使用AVAudioPlayerDelegate的方法

- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag 

您的viewcontroller/class與audioplayer實例必須是音頻播放器的代表。該方法將在音頻播放器完成播放時調用。

http://developer.apple.com/library/ios/#documentation/AVFoundation/Reference/AVAudioPlayerDelegateProtocolReference/Reference/Reference.html