>>Hi Viv,
>>
>>hmmm, What does this mean?
>>
>>> with WPF, you should never use base classes to impose any visual appearance on derived classes.
>
>Well, put it this way: I can't think of any reason why you would do so when you can use Styles or Control Templates; hard-coding appearance by using a base class pretty much negates those benefits of XAML.....
>
>TBH, since I work a lot with MVVM, I can't think of many reasons to define behaviour within the base class of a visual object either....

Ok, now I understand. I was having trouble comprehending this morning what it was that meant. I agree, on both counts. I have been doing MVVM as well and right now dealing with an application that has every control subclassed and because of this, no designer support on any visual view. Everytime something is broken we have to first determine if this is because of the subclassed controls. Even all the third party stuff has been subclassed. I am not thinking this was a great idea.

Thanks for clarifying.
Timothy