WKWebView禁止捏合的方法

    func webView(_ webView: WKWebView, didCommit navigation: WKNavigation!) {        let javascript = "var meta = document.createElement('meta');meta.setAttribute('name', 'viewport');meta.setAttribute('content', 'width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no');document.getElementsByTagName('head')[0].appendChild(meta);"        webView.evaluateJavaScript(javascript, completionHandler: nil)    }