swift -通过单击UIWebView中的按钮打开ViewController

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建一个UIWebView
        let webView = UIWebView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height))
        view.addSubview(webView)
        
        // 加载一个网页
        let url = URL(string: "https://www.example.com")
        let request = URLRequest(url: url!)
        webView.loadRequest(request)
        
        // 创建一个按钮
        let button = UIButton(frame: CGRect(x: 100, y: 100, width: 100, height: 50))
        button.setTitle("打开新页面", for: .normal)
        button.setTitleColor(.blue, for: .normal)
        button.addTarget(self, action: #selector(openNewViewController), for: .touchUpInside)
        view.addSubview(button)
    }
    
    @objc func openNewViewController() {
        // 创建一个新的ViewController
        let newViewController = UIViewController()
        newViewController.view.backgroundColor = .white
        
        // 在导航栏中显示返回按钮
        let backButton = UIBarButtonItem(title: "返回", style: .plain, target: self, action: #selector(back))
        newViewController.navigationItem.leftBarButtonItem = backButton
        
        // 创建一个UILabel
        let label = UILabel(frame: CGRect(x: 100, y: 200, width: 200, height: 50))
        label.text = "新的ViewController"
        label.textAlignment = .center
        newViewController.view.addSubview(label)
        
        // 使用导航控制器打开新的ViewController
        navigationController?.pushViewController(newViewController, animated: true)
    }
    
    @objc func back() {
        // 返回上一个ViewController
        navigationController?.popViewController(animated: true)
    }
}