c# - Query string not recognized -

I have to follow the problem: when I go to my site:

  Http : // localhost: 9684 / MainPage.aspx? UserID = VABRAEIAUgBBAEUARQBBAFAAUQBBAD0A  

Check that if there is a query string (UserID) and if there is a query string in it, save this variable in sIngelogdID I am using the following code:

  string sIngelogdID = System.Web.HttpContext.Current.Request.QueryString ["UserID"];  

However, when I look into debug mode it says that there are 0 query strings, so it does not see the UserID as a query string.
It's written in a WCF-RIA-service.
Does anyone know how to get it?
Thanks in advance!

Edit: UserID comes from a different Silverlight 4 application on this application the user enters after logging in (the user's ID that is logged in) Some other Silverlight 4 applications have to be passed. If there is another way (better) way of achieving this, please let me know.

You use to send value instead.

Firstly capture QuickString from the ASPX page, which hosts your Silverlight application, the main page. Espacks C

  public string GetUserId () {return HttpContext.Current.Request.QueryString ["user id"]; }  

Now under MainPage.aspx, you need to insert code as below body => form => get the ultimate and add

  & Lt; Param name = "intrim" value = "param1 = & lt;% = getUserId ()%> & gt; / & Gt;  

Now capture the param1 in App.xaml.cs Application_Startup method as

  if (e.InitParams.ContainsKey ("param1")) {UserId = E. Interpram [[Param 1]]. Toasting (); }  

Hope this helps