title: HttpContext null in Signalr OnConnected method
body: <p>I am using signalr, but facing an issue in the <code>Onconnected</code> method. I need <code>urlreferrer</code> here but I get a null pointer exception.</p>
  
  <pre><code>public override Task OnConnected()
  {
      string urlreferrer = HttpContext.Current.Request.UrlReferrer.ToString(); 
      // Getting null exception here..
      return base.OnConnected();
  }
  </code></pre>
  
  <p>How can I solve this?</p>