Load different content into WebBrowser control based on navigated URL

I've a HTML & JavaScript code locally loaded into a WebBrowser control. The JavaScript code tries loading some data from a url using ajax. I can change the request url to a custom url (something like: app://request1), but I've no idea how to manage the content that should be returned to the ajax http request (through WebBrowser control)! I can see requested URLs by handling Navigating event of WebBrowser control, but there is nothing to set as a return value for the request.

Something like:

private void webBrowser1_Navigating(object sender, 
WebBrowserNavigatingEventArgs e)
{
    switch(e.Url.AbsoluteUri)
    {
         case "app://request1":
              e.ResponseString = "response string 1";
              break;
         case "app://request2":
              e.ResponseString = "response string 2";
              break;
    }
}

I've searched a lot but found nothing.

one idea that has crossed my mind is implementing a local http server (tcp socket listening on a specific port number) and change the ajax request url to that local listening socket.