title: Subclassing DropDownList in ASP.NET
body: <p>I want to subclass the built-in DropDownList in ASP.NET so that I can add functionality to it and use it in my pages. I tried doing this with a UserControl but found that it doesn't expose the internal DropDownList (logically, I guess). I've googled for the answer but can't find anything. </p>
  
  <p>I've come as far as writing the actual class, and it's possible to subclass from DropDownList but I'm unable to register the file in my ASP.NET page and use it in the source view. Maybe I'm missing some properties in my class?</p>
  
  <p>Any ideas?</p>