检查请求 URL 是否包含 swift webview

Question

我正在尝试检查 URL 是否包含诸如“www.example.com/?external=1”之类的“外部”，然后它应该在外部浏览器中打开，否则在下面本地打开是代码，请帮我解决这个问题。 谢谢

class ViewController: UIViewController, WKNavigationDelegate {

    let webView = WKWebView()

    override func viewDidLoad() {
        super.viewDidLoad()
        
        webView.frame = view.bounds
        webView.navigationDelegate = self

        let url = URL(string: "https://www.example.com")!
        let urlRequest = URLRequest(url: url)

        webView.load(urlRequest)
        webView.autoresizingMask = [.flexibleWidth,.flexibleHeight]
        view.addSubview(webView)
    }

    func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
        if navigationAction.navigationType == .linkActivated  {
            if let url = navigationAction.request.url,
                let host = url.host, !host.hasPrefix("external"),
                UIApplication.shared.canOpenURL(url) {
                UIApplication.shared.open(url)
                print(url)
                print("Redirected to browser. No need to open it locally")
                decisionHandler(.cancel)
                return
            } else {
                print("Open it locally")
                decisionHandler(.allow)
                return
            }
        } else {
            print("not a user click")
            decisionHandler(.allow)
            return
        }
    }
}

我试图更改代码，例如：

url.hasPrefix("external")

但它给出错误“URL 类型的值没有成员'hasPrefix'”