从Swift 4.0 WebView移除上下文菜单

Question

我想禁用上下文菜单，即维护WKWebView swift 4元素的任何操作

import UIKit
import WebKit

class ViewController: UIViewController, WKNavigationDelegate {
    var webView: WKWebView!

    override func loadView() {
        webView = WKWebView()
        webView.navigationDelegate = self
        view = webView

    }

    override func viewDidLoad() {
        super.viewDidLoad()

        // 1
        let url = URL(string: "https://www.google.com")!
        webView.load(URLRequest(url: url))

        // 2
        let refresh = UIBarButtonItem(barButtonSystemItem: .refresh, target: webView, action: #selector(webView.reload))
        toolbarItems = [refresh]
        navigationController?.isToolbarHidden = false

    }

    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        title = webView.title
    }

    func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
        //show progress indicator
    }
    func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
        //show error
    }
    func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) {
        //show error
    }

    private weak var lastPresentedController : UIViewController?

    override func dismiss(animated flag: Bool, completion: (() -> Void)? = nil) {
        // WKWebView actions sheets workaround
        if presentedViewController != nil && lastPresentedController != presentedViewController  {
            lastPresentedController = presentedViewController;
            presentedViewController?.dismiss(animated: flag, completion: {
                completion?();
                self.lastPresentedController = nil;
            });

        } else if lastPresentedController == nil {
            super.dismiss(animated: flag, completion: completion);
        }
    }
}