//獲得當(dāng)前屏幕亮度
  light = [UIScreen mainScreen].brightness;
  light = 0.5f;
  //直接賦值或者使用set方法皆可
  [UIScreen mainScreen].brightness = light;

MPMusicPlayerController *mpVC = [MPMusicPlayerController applicationMusicPlayer];
//獲得系統(tǒng)當(dāng)前音量
voice = _mpVC.volume;
voice = 0.5f;
//改變系統(tǒng)音量
_mpVC.volume = voice;

- (void)leftSwipGes:(UIPanGestureRecognizer *)leftSwip
{
  //滑動方法獲取到當(dāng)前位置的y坐標(biāo)
  leftCurrentY = [leftSwip translationInView:leftView].y;
  NSLog(@"left");
  //當(dāng)前坐標(biāo)大于上一次移動的坐標(biāo)，為向下滑動
  if (leftCurrentY > leftLastY) {
    if (light > 0) {
      //向下滑動屏幕變暗，亮度下降
      light = light - 0.01;
    }
    else{
      //當(dāng)亮度為0時(shí)固定為0，禁止為負(fù)值
      light = 0;
    }
  }
  else
  {
    if (light < 1) {
      //向上滑動亮度增加
      light = light + 0.01;
    }
    else{
      //當(dāng)亮度為1時(shí)固定為1，禁止大于1
      light = 1;
    }
  }
  //設(shè)置屏幕亮度
  [UIScreen mainScreen].brightness = light;
  //當(dāng)前位置的上一次移動的位置y坐標(biāo)
  leftLastY = leftCurrentY;
}
//此處除參數(shù)外原理一樣，不再額外注釋
- (void)rightSwipGes:(UIPanGestureRecognizer *)rightSwip
{
  NSLog(@"right");
  rightCurrentY = [rightSwip translationInView:rightView].y;
  if (rightCurrentY > rightLastY) {
    if (voice > 0) {
      voice = voice - 0.01;
    }
    else{
      voice = 0;
    }
  }
  else
  {
    if (voice < 1) {
      voice = voice + 0.01;
    }
    else{
      voice = 1;
    }
  }
  //設(shè)置系統(tǒng)音量
  _mpVC.volume = voice;
  rightLastY = rightCurrentY;
}

//從budle路徑下讀取音頻文件,這個(gè)文件名是你的歌曲名字,mp3是你的音頻格式
  NSString *string = [[NSBundle mainBundle] pathForResource:@"夜空中最亮的星" ofType:@"mp3"];
  NSString *playUrl = [string stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; //轉(zhuǎn)碼成UTF-8 否則可能會出現(xiàn)錯(cuò)誤
  //把音頻文件轉(zhuǎn)換成url格式
  NSURL *url = [NSURL URLWithString:playUrl];
  //初始化音頻類 并且添加播放文件
  _avAudioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
  [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
  //設(shè)置初始音量大小
  _avAudioPlayer.volume = voice;
  //設(shè)置音樂播放次數(shù) -1為一直循環(huán)
  _avAudioPlayer.numberOfLoops = -1;
  //預(yù)播放
  [_avAudioPlayer prepareToPlay];
  [_avAudioPlayer play];

 [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];