I am trying to add a footer row of DropDownLists to my GridView control. The problem is that I do not know how many columns will be in my DataSource at design time, so I am trying to use the AutoGenerateColumns=true and not specify the column templates. Therefore the way I am adding the DropDownList controls to the footer is in code dynamically on the DataBound event of the GridView.

This works fine except that I would like to do something with the SelectedItem of each of the DropDownLists when the users clicks a button. These dynamically added controls no longer seem to exist on the post back of the user clicking the button, I believe the problem is because I am not specifying the runat="server" tag on the DropDownList controls. 

Is there a different way I could be adding these drop downs to a FooterTemplate without specifying all of the columns so I can have access to their SelectedItems when the user clicks a button on the page?