title: How to pass query string parameter in asp.net?
body: <p>I am using Access Control service (ACS). I fetched all identity providers (ip) which i set for my application using the following code :</p>
  
  <pre><code>    public ActionResult IdentityProviders(string serviceNamespace, string appId)
      {
          string idpsJsonEndpoint = string.Format(Global.IdentityProviderJsonEndpoint, serviceNamespace, appId);
          var client = new WebClient();
          var data = client.DownloadData(idpsJsonEndpoint);
  
          return Content(Encoding.UTF8.GetString(data), "application/json");
      }
  </code></pre>
  
  <p>When user click over the signin link the above code called using ajax and get the ips and display them in jquery-ui dialog. And when user click any one of the ips for login the browser redirect to the selected ip login page. After successful login the control return to my control which i set as a returnUrl. Upto this every thing is works fine. </p>
  
  <p>Now what i am trying to do is to pass some values to identity provider (ip) login page and want to get back those values at my returnUrl controller. For this i searched and came to know that there is a query string parameter known as <code>wctx</code> which we can set and get the value at return url. But i dont know how to do this. Can anybody please guid me how can i achieve this? </p>