Abstract UserControl inheritance in Visual Studio designer

Question

abstract class CustomControl : UserControl 
{
    protected abstract int DoStuff();
}

class DetailControl : CustomControl
{
    protected override int DoStuff()
    { 
        // do stuff
        return result;
    }
}

I dropped a DetailControl in a form. It renders correctly at runtime, but the designer displays an error and won't open because the base user control is abstract.

For the moment, I'm contemplating the following patch, which seems pretty wrong to me, as I want the child classes to be forced to implement the method.

class CustomControl : UserControl 
{
    protected virtual int DoStuff()
    {
        throw new InvalidOperationException("This method must be overriden.");
    }
}

class DetailControl : CustomControl
{
    protected override int DoStuff()
    { 
        // do stuff
        return result;
    }
}

Anyone has a better idea on how to work my way around this problem?

Answer 1

You can use a TypeDescriptionProviderAttribute to provide a concrete design-time implementation for your abstract base class. See http://wonkitect.wordpress.com/2008/06/20/using-visual-studio-whidbey-to-design-abstract-forms/ for details.