随笔-app音量slider与系统音量统一同步

用到了音量跟系统设备的音量要同步，随手整理一下。

导入框架：<MPMusicPlayerController.framework>

#import <MediaPlayer/MediaPlayer.h>

注册通知：

- (void)viewDidLoad {
//系统音量变化时，调整volumeSlider 的值
 

MPMusicPlayerController *MPMusciPlayer = [MPMusicPlayerController applicationMusicPlayer];
[MPMusciPlayer beginGeneratingPlaybackNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(changeVolumeSlider)
name:MPMusicPlayerControllerVolumeDidChangeNotification
object:nil];

}

实现代理方法：

//音量按钮
- (IBAction)slidervaluechange:(UISlider *)sender {
MPMusicPlayerController *mp=[MPMusicPlayerController applicationMusicPlayer];
mp.volume=self.yinliangslider.value;


}

实现通知方法changeVolumeSlider:

-(void)changeVolumeSlider{
self.yinliangslider.value = [[MPMusicPlayerController applicationMusicPlayer] volume];
}

到这里就OK了，三部曲 is so easy!