Ios 如何检测用户何时在AVPlayer中选择一个字幕选项？目前我无法退出AVPLayer中的字幕选项

无法退出AVPlayer中的字幕选项覆盖。即使单击其中一个选项，也无法取消覆盖

当用户选择其中一个字幕选项时，是否有任何侦听器或方法来检测

Im使用XCode 11.6

func setAVKitPlayer() {
    let player = AVPlayer(url:  self.videoUrl)
    let asset = AVAsset(url: self.videoUrl)
    let playerItem = AVPlayerItem(asset: asset)
    avPlayerViewController.delegate = self

    videoPlayer = player
    avPlayerViewController.player = videoPlayer
    avPlayerViewController.player?.replaceCurrentItem(with: playerItem)
    avPlayerViewController.showsPlaybackControls = true
    
    avPlayerViewController.view.frame = CGRect(x: 0, y: 0, width: self.videoView.frame.width, height: self.videoView.frame.height)
            
    self.videoView.addSubview(avPlayerViewController.view)
    avPlayerViewController.delegate = self
    
    videoPlayer.play() 
}

请参阅此图：