無法接收remoteControlReceivedWithEvent - 目標c - ios

我成功啓用了我的應用程序，以便能夠在屏幕鎖定後在後臺播放音頻和視頻。但是，爲了獲得更好的用戶體驗，我希望在鎖定的屏幕上顯示播放和暫停正在運行的媒體的控件。在線下的情侶博客後，添加以下代碼：在info.plist中無法接收remoteControlReceivedWithEvent - 目標c - ios

@interface MyControllerClass() <UIGestureRecognizerDelegate, UIApplicationDelegate> 

- (void)viewDidAppear:(BOOL)animated { 
[super viewDidAppear:animated]; 
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents]; 
[self becomeFirstResponder]; 

    AVURLAsset *avAsset = [AVURLAsset URLAssetWithURL:url options:nil]; 
    AVPlayerItem *playerItem = [AVPlayerItem playerItemWithAsset:avAsset]; 
    AVAudioSession *session = [AVAudioSession sharedInstance]; 
    [session setCategory:AVAudioSessionCategoryPlayback error:nil]; 
    NSError *activationError = nil; 
    BOOL success = [[AVAudioSession sharedInstance] setActive: YES error: &activationError]; 
} 

- (void)viewWillDisappear:(BOOL)animated { 
[[UIApplication sharedApplication] endReceivingRemoteControlEvents]; 
[self resignFirstResponder]; 
[super viewWillDisappear:animated]; 
} 

- (BOOL) canBecomeFirstResponder { 
return YES; 
} 

- (void) remoteControlReceivedWithEvent: (UIEvent *) receivedEvent { 
NSLog(@"received event %@",receivedEvent); 
if (receivedEvent.type == UIEventTypeRemoteControl) { 
    switch (receivedEvent.subtype) { 
     case UIEventSubtypeRemoteControlTogglePlayPause: { 
      if ([self isVideoPlaying]) { 
       [self.avPlayer pause]; 
      } else { 
       [self.avPlayer play]; 
      } 
      break; 
     } 
     case UIEventSubtypeRemoteControlPlay: { 
      [self.avPlayer play]; 
      break; 
     } 
     case UIEventSubtypeRemoteControlPause: { 
      [self.avPlayer pause]; 
      break; 
     } 
     default: 
      break; 
    } 
} 
}

增加的背景模式，即使我能看到的控制屏幕，沒有用戶事件通過點擊按鈕我的應用程序收到。