title: Accessing ViewBag in Controller that's set in a view
body: <p>I understand I can do this using ModelBinding, but I'd like to know if I can use the <code>ViewBag</code></p>
  
  <p>I set the <code>ViewBag</code> property in the View</p>
  
  <pre><code>@{
  ViewBag.WasPriorityCustomer = Model.PriorityCustomer == true;
  }
  </code></pre>
  
  <p>A user who is not a priority customer can be changed to one, but i need to know if they were a priority customer to begin with.</p>
  
  <p>In the controller</p>
  
  <pre><code>[HttpPost]
  public ActionResult Save(MyModel model)
  {
    if (ViewBag.WasPriorityCustomer == false &amp;&amp; model.PriorityCustomer == true)
    {
      //Thank you for becoming a priority customer
    }
  }
  </code></pre>
  
  <p>Unfortunately <code>ViewBag.WasPriorityCustomer</code> is always null</p>