如何向iOS UIWebView添加导航？

let webView = UIWebView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height))
view.addSubview(webView)

if let url = URL(string: "https://www.example.com") {
    let request = URLRequest(url: url)
    webView.loadRequest(request)
}

// 添加返回按钮
let backButton = UIBarButtonItem(title: "返回", style: .plain, target: self, action: #selector(goBack))
navigationItem.leftBarButtonItem = backButton

// 返回按钮的点击事件
@objc func goBack() {
    if webView.canGoBack {
        webView.goBack()
    }
}

// 添加前进按钮
let forwardButton = UIBarButtonItem(title: "前进", style: .plain, target: self, action: #selector(goForward))
navigationItem.rightBarButtonItem = forwardButton

// 前进按钮的点击事件
@objc func goForward() {
    if webView.canGoForward {
        webView.goForward()
    }
}

// 设置WebView的代理
webView.delegate = self

// 实现WebView加载完成的代理方法
func webViewDidFinishLoad(_ webView: UIWebView) {
    // WebView加载完成后的处理
}

// 实现WebView加载失败的代理方法
func webView(_ webView: UIWebView, didFailLoadWithError error: Error) {
    // WebView加载失败时的处理
}