C# generics usercontrol

This works

public class Control1<T> : UserControl { ... }

public class Control2 : Control1<double> { ... }

public class Control3 : Control2 { ... }

had read it here:

Generic User Controls?

Sounds much like what we do in our project.

There's a base class that is generic:

public partial class controlItemList<TBaseItem, TBaseItemCollection> : UserControl, IUIDispatcher
    where TBaseItem : new()
    where TBaseItemCollection : IItemCollection<TBaseItem>

Then for each use we define a non-generic version (which still couldn't be used by designer):

public class controlMessagesNonGenericParent : controlItemList<MailItem, MailItemCollection>
{
}

... and then we have derived controls that could be used in designer:

public partial class controlMessages : controlMessagesNonGenericParent
{
...
}