如何在重新加载视图控制器后仍然显示progressView的进度？

import UIKit

class ViewController: UIViewController {
    var progressView: UIProgressView!
    var progress: Float = 0.0
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        progressView = UIProgressView(progressViewStyle: .default)
        progressView.frame = CGRect(x: 50, y: 100, width: 200, height: 20)
        view.addSubview(progressView)
        
        updateProgress()
        
        DispatchQueue.global().async {
            // 模拟耗时操作
            for i in 0..<100 {
                self.progress = Float(i) / 100.0
                DispatchQueue.main.async {
                    self.updateProgress()
                }
                usleep(100000) // 模拟耗时操作的延迟
            }
        }
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        updateProgress()
    }
    
    func updateProgress() {
        progressView.progress = progress
    }
}