void NavigateWithWebResourceRequestCmdExecuted(object target, ExecutedRoutedEventArgs e) { // Prepare post data as UTF-8 byte array and convert it to stream // as required by the application/x-www-form-urlencoded Content-Type var dialog = new TextInputDialog( title: "NavigateWithWebResourceRequest", description: "Specify post data to submit to https://www.w3schools.com/action_page.php."); if (dialog.ShowDialog() == true) { string postDataString = "input=" + dialog.Input.Text; UTF8Encoding utfEncoding = new UTF8Encoding(); byte[] postData = utfEncoding.GetBytes( postDataString); MemoryStream postDataStream = new MemoryStream(postDataString.Length); postDataStream.Write(postData, 0, postData.Length); postDataStream.Seek(0, SeekOrigin.Begin); CoreWebView2WebResourceRequest webResourceRequest = WebViewEnvironment.CreateWebResourceRequest( "https://www.w3schools.com/action_page.php", "POST", postDataStream, "Content-Type: application/x-www-form-urlencoded\r\n"); webView.CoreWebView2.NavigateWithWebResourceRequest(webResourceRequest); } }