How do I create a Silverlight 4 dll that Silverlight 3 applications cannot consume?

Question

I have compiled a silverlight library that is set to Silverlight version 4 in the project properties. It consumes a dll with silverlight 4 dependencies. When I am on a system that only has silverlight 3 installed, I can reference the original silverlight library without error. At runtime I get an error about a class not existing in mscorelib. This is the behavior I would expect, except I would like to not be able to import the silverlight library at all if its not running silverlight 4. Am I missing something about how silverlight works, or should there be a way to prevent the consumption of my library before runtime on a system of an improper version?

Answer 1

To be fair, in Silverlight a library is a library is a library, so it assumes any missing assemblies will be supplied.

I think we may have to put this down to a "feature" of Visual Studio in that it does not exhaustively check dependencies for correct target types.