根据swift中的滑块更改滑块值和音频移动

Question

我正在研究音乐音频。我想更改滑块值，同样音频值也会改变。

       var avPlayer:AVPlayer!
    var avPlayerItem:AVPlayerItem!


                    if let audioUrl = URL(string: self.idMusicFile) {
                        let documentsDirectoryURL =  FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
                        // destination file url
                        let destinationUrl = documentsDirectoryURL.appendingPathComponent(audioUrl.lastPathComponent)
                        print("destinationUrl is :",destinationUrl)
                        self.avPlayerItem = AVPlayerItem(url: destinationUrl)
                        self.avPlayer=AVPlayer(playerItem: self.avPlayerItem!)
                        self.avPlayer?.play()
                    }

     var updater : CADisplayLink! = nil

      self.updater = CADisplayLink(target: self, selector: #selector(NearByViewController.trackAudio))
                    self.updater.add(to: RunLoop.current, forMode: RunLoopMode.commonModes)

    @objc func trackAudio() {
    //   if self.avPlayer.currentTime() = ""{}
    let fraction = CMTimeGetSeconds((self.avPlayer?.currentTime())!) / CMTimeGetSeconds((self.avPlayer?.currentItem!.duration)!)
    print("fraction",fraction)
    self.sliderValue.value = Float(fraction)

}

此代码正在播放音频可以任何人建议我如何实现滑块更改然后音频也根据滑块值移动