禁用iOS网络应用程序中的"保存图像"

document.addEventListener('contextmenu', function(e) {
  e.preventDefault();
});

img {
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  -khtml-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

import WebKit

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

    override func viewDidLoad() {
        super.viewDidLoad()

        let configuration = WKWebViewConfiguration()
        let userContentController = WKUserContentController()
        configuration.userContentController = userContentController

        webView = WKWebView(frame: .zero, configuration: configuration)
        webView.navigationDelegate = self
        view.addSubview(webView)

        let layoutGuide = view.safeAreaLayoutGuide
        webView.translatesAutoresizingMaskIntoConstraints = false
        webView.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor).isActive = true
        webView.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor).isActive = true
        webView.topAnchor.constraint(equalTo: layoutGuide.topAnchor).isActive = true
        webView.bottomAnchor.constraint(equalTo: layoutGuide.bottomAnchor).isActive = true

        let source = """
            var script = document.createElement('script');
            script.innerHTML = 'document.addEventListener("contextmenu", function(e) { e.preventDefault(); }); img { -webkit-touch-callout: none; -webkit-user-select: none; -khtml-user-select: none; -moz-user-select: none; -ms-user-select: none; user-select: none; }';
            document.body.appendChild(script);
        """

        webView.evaluateJavaScript(source, completionHandler: nil)
    }
}