如何在按钮点击时播放来自URL的音频，并在swift中的滑块或进度条上显示进度。

import UIKit
import AVFoundation

class ViewController: UIViewController {
    var player: AVPlayer?
    var playerItem: AVPlayerItem?
    
    @IBOutlet weak var playButton: UIButton!
    @IBOutlet weak var progressSlider: UISlider!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // 初始化AVPlayer
        guard let audioURL = URL(string: "音频的URL") else { return }
        playerItem = AVPlayerItem(url: audioURL)
        player = AVPlayer(playerItem: playerItem)
        
        // 监听播放进度
        player?.addPeriodicTimeObserver(forInterval: CMTime(seconds: 1, preferredTimescale: CMTimeScale(NSEC_PER_SEC)), queue: DispatchQueue.main) { [weak self] time in
            guard let duration = self?.playerItem?.duration else { return }
            let currentTime = CMTimeGetSeconds(time)
            let totalDuration = CMTimeGetSeconds(duration)
            let progress = Float(currentTime / totalDuration)
            self?.progressSlider.value = progress
        }
    }
    
    @IBAction func playButtonTapped(_ sender: UIButton) {
        if player?.rate == 0 {
            // 播放音频
            player?.play()
            playButton.setTitle("暂停", for: .normal)
        } else {
            // 暂停音频
            player?.pause()
            playButton.setTitle("播放", for: .normal)
        }
    }
    
    @IBAction func progressSliderValueChanged(_ sender: UISlider) {
        guard let duration = playerItem?.duration else { return }
        let totalDuration = CMTimeGetSeconds(duration)
        let currentTime = Double(sender.value) * totalDuration
        let time = CMTime(seconds: currentTime, preferredTimescale: CMTimeScale(NSEC_PER_SEC))
        player?.seek(to: time)
    }
}