Adding string to bound field

Question

trying to add a prefix before bound field

<label><input type="radio" name="rbGroup" value='r<%#((Type)Container.DataItem).ID %>'/><%# ((Type)Container.DataItem).Action %></label>

but it's putting r next to the button. I want rID

Answer 1

value='<%#"r"+((Type)Container.DataItem).ID %>'