It sounds like a chicken-and-egg...you want to define something at the framework level based on something that "will be" in the application level...I would be curious if there is some way around it, but i doubt it...I don't think that at one level of class library you can make assumptions about a subclassed library...

I will watch this thread for solutions! Would be handy...

Joe

>My class libraries look something like:
>

txtBase
>  txtStd
>    txtFrame
>      txtApp

>
>In the Framework level of my libraries, I'll define a CSZ container class, which takes a Zipcode and fills in the City and State. Then,
>I'll subclass it at the App level. However, it is still using the
>textboxes from the Framework level, rather than the App level. Is
>there any way to subclass a container class and get it to pick up
>the "correct" user interface elements?
>
>Or do I have to break the behavior out into a custom class, and
>just use the textboxes at the correct level, rather than a subclassed
>containerL