title: Is it possible to re-DataBind a DropDownList upon postback triggered by SelectedIndexChanged event?
body: <p>Let's say I have a DropDownList of product categories and a ListView of products based on the category selection in the DropDownList. When a user visits the page, there is a possibility of conconrency issue as new product belonging to a new category may be added to the inventory as the user is browsing.</p>
  
  <p>When the user selects a different category to view(a SelectedIndexChanged event) and causes a postback, I want the DropDownList to update the list of categories to include the new category being concurrently added and at the same time still able to make a change of selected index. The DropDownList does not seem to support this updating while postback. So how do I handle this concurrent issue?</p>