iOS開發--QQ音樂練習,後臺播放和鎖屏界面

一.設置後臺播放

• 首先容許程序後臺播放
• 代碼實現

   1 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
   2     
   3     // 設置後臺播放的代碼,步驟
   4     // 1.獲取音頻的會話
   5     AVAudioSession *session = [AVAudioSession sharedInstance];
   6     // 2.設置後臺播放類型
   7     [session setCategory:AVAudioSessionCategoryPlayback error:nil];
   8     // 3.激活會話
   9     [session setActive:YES error:nil];
  10     
  11     return YES;
  12 }

   

二.鎖屏界面

• 適當的時機調用這個方法                                                                              

  #pragma mark - 設置鎖屏界面的信息
  - (void)setupLockScreenInfo
  {
      // 1.獲取當前正在播放的歌曲
      ChaosMusic *playingMusic = [ChaosMusicTool playingMusic];
      // 2.獲取鎖屏界面中心
      MPNowPlayingInfoCenter *playingCenter = [MPNowPlayingInfoCenter defaultCenter];
      // 3.設置展現的信息
      NSMutableDictionary *playingInfo = [NSMutableDictionary dictionary];
      
      playingInfo[MPMediaItemPropertyAlbumTitle] = playingMusic.name;
      playingInfo[MPMediaItemPropertyArtist] = playingMusic.singer;
      MPMediaItemArtwork *artwork = [[MPMediaItemArtwork alloc] initWithImage:[UIImage imageNamed:playingMusic.icon]];
      playingInfo[MPMediaItemPropertyArtwork] = artwork;
      playingInfo[MPMediaItemPropertyArtist] = @(self.player.currentTime);
      
      playingCenter.nowPlayingInfo = playingInfo;
      // 4.讓應用程序能夠接受遠程事件
      [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
  }

   

• 實現了鎖屏界面,沒有實現監聽遠程事件的話,鎖屏界面的下一首之類的按鈕沒有反應.實現下面的方法

   1 // 監聽遠程事件
   2 - (void)remoteControlReceivedWithEvent:(UIEvent *)event
   3 {
   4     switch (event.subtype) {
   5         case UIEventSubtypeRemoteControlPlay:
   6         case UIEventSubtypeRemoteControlPause:
   7             [self startOrPause:nil];
   8             break;
   9             
  10         case UIEventSubtypeRemoteControlNextTrack:
  11             [self nextMusic:nil];
  12             break;
  13             
  14         case UIEventSubtypeRemoteControlPreviousTrack:
  15             [self previousMusic:nil];
  16             break;
  17             
  18         default:
  19             break;
  20     }
  21 }