@interface ViewController ()<AVAudioPlayerDelegate>

{

  AVAudioPlayer *audioPlayer;

}

@end

UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
  button.frame = CGRectMake(100, 100, 100, 100);
  button.backgroundColor = [UIColor brownColor];
  [button setTitle:@"Play" forState:UIControlStateNormal];
  [button setTitle:@"Pause" forState:UIControlStateSelected];
  [button addTarget:self action:@selector(play:) forControlEvents:UIControlEventTouchUpInside];
  [self.view addSubview:button];

   [self playMusicWithName:@"TFBOYS-青春修炼手册.mp3"];

- (void)play:(UIButton *)sender{
  sender.selected = !sender.selected;
  sender.selected != YES ? [audioPlayer pause]:[audioPlayer play];
}

- (void)playMusicWithName:(NSString *)name{
  NSError *error;
  
//  创建一个音乐播放对象
  audioPlayer = [[AVAudioPlayer alloc]initWithContentsOfURL:[[NSBundle mainBundle]URLForResource:name withExtension:nil] error:&error];
  if (error) {
    NSLog(@"%@",error);
  }
 
  预播放
  [audioPlayer prepareToPlay];
  
  播放 在这里不写在这 但它是必须的步骤
  [audioPlayer play];
  
  获取 当前音乐的声道
  NSLog(@"%ld",audioPlayer.numberOfChannels);
  
  durtion：获得播放音频的时间
  
  设置声道 -1.0左 0.0中间 1.0右
  audioPlayer.pan = 0.0;
  

  音量
  audioPlayer.volume = 0.1;
  
  设置速率 必须设置enableRate为YES
  audioPlayer.enableRate = YES;
  设置速率 0.5是一半的速度 1.0普通 2.0双倍速率
  audioPlayer.rate = 1.0;
  
  currentTime 获得时间
  获得峰值 必须设置meteringEnabled为YES
  audioPlayer.meteringEnabled = YES;
  更新峰值
  [audioPlayer updateMeters];  
  获得当前峰值
  NSLog(@"当前峰值：%f",[audioPlayer peakPowerForChannel:2]);
  NSLog(@"平均峰值%f",[audioPlayer averagePowerForChannel:2]);
  
  设置播放次数 负数是无限循环的 0 是一次 1是两次 依次类推
  audioPlayer.numberOfLoops = 0;
  挂上代理
  audioPlayer.delegate = self;
  
}