Stringy stringy bang bang

I had a simple scenario: Array of strings bound to a GridView. Initially, with auto generation of columns, this is easy. You get a single column with all the strings in the array. But then I needed to do something practical with it, so thus needed to specify the columns:

  <Columns>
     <asp:BoundField DataField="?????" />
     ...
  </Columns>

I noticed that the column header said "Item" when auto generated so I tried that, but it didn't work. So then, I ask myself, what is the data field of a System.String? The only bindable member (public field or property) is .Length. Good to know but useless in this case. The ToString() member is a method so it can't be bound to. But apparently there is an undocumented trick: Use the exclamation point (!) as the datafield value and you'll get the string's value.

 <asp:BoundField DataField="!" />

This yields the desired result.