How to expand Visual Studio variables in the add-in code?

Question

I'm working on a VS add-in. How do I expand variables like $(ProjectDir)?

Answer 1

I think you want something similar to what an answer to a related question on SO describes.

The linked answer speaks to VC++ projects and VCProject etcetera; but a quick search yielded the VSProject interface, which seems to provide a starting point for something similar with C#/VB.NET projects.

Specifically check out the VSProject.Project property and the Project.ConfigurationManager property to which the VSProject interface page directly and indirectly links.