使用UISlider更改音量

import UIKit
import AVFoundation

class ViewController: UIViewController {

    @IBOutlet weak var volumeSlider: UISlider!
    var audioPlayer: AVAudioPlayer?

    override func viewDidLoad() {
        super.viewDidLoad()

        // 加载音频文件
        if let url = Bundle.main.url(forResource: "background_music", withExtension: "mp3") {
            do {
                audioPlayer = try AVAudioPlayer(contentsOf: url)
                audioPlayer?.play()
            } catch {
                print("无法加载音频文件")
            }
        }
    }

    @IBAction func volumeChanged(_ sender: UISlider) {
        // 获取用户选择的音量值
        let volume = sender.value

        // 将音量值应用到音频播放器中
        audioPlayer?.volume = volume
    }
}