public void ScanQR()
 {
     qrScanner.ScanQR()
     .ContinueWith((t) =>
     {
         //var js = string.Format("getQRValue('{0}');", t.Result);
         //webView.LoadUrl("javascript:" + js);
         //call the Javascript method here with "result" as its parameter to get the scanned value
         if (t.Status == TaskStatus.RanToCompletion)
         {
             webView.LoadUrl(@"javascript:getQRValue('" + t.Result + "')");
         }
     });
 }