Question

Is there a way to add items to a dropdownlist (or any other control with lists) and when SelectedIndexChange happens, it doesn’t keep adding all the items everytime that event happens?
I suppose one way would be to clear the list before the add code but is there another?

Answer 1

It looks like you are adding items to the list on Page_Load event. If you are doing that, in that case when ever SelectedIndexChanged occurs it will add the items again. You can check if its a PostBack don’t add items.

if(!Page.IsPostBack) // First time only 
 {
  //Add items to list
 }