Themes for Custom Controls in ASP.NET

Q: How do you skin custom controls and user controls in ASP.NET 2.0?

A: You can use an @ Register directive in the .skin file. Once the control is registered, skinning works just as you'd expect. For instance, the following control:

Can be skinned like so:

The above Register directive assumes your control is defined in App_Code, otherwise you'll need to add the Assembly attribute to specify the assembly. It’s also important to note that a skin defined using <asp:Calendar> will not apply to the MyCalendar control, even though they have an inheritance relationship. The theme algorithm does an exact match on the control’s type.