swift wkwebview 禁止两手指缩放

funcwebView(_webView:WKWebView,didFinish navigation:WKNavigation!){letjavascript="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)}