We just ran into surprising behaviour in VS.NET 2010 SP1. We’re not sure if this is new or we never noticed it before.
Imagine a solution with two projects: A (ASP.NET web application in C#) & B (regular DLL in C#). A references the project B. Therefore, B’s DLL gets copied over to A’s bin folder when rebuilding the full solution.
- If you build project A, it will also build all of it’s dependencies first. Hence, both get rebuilt.
- If you build project B, only B is rebuilt.
We’ve noticed that when rebuilding B, an updated DLL appears in A’s bin folder. This surprises me, as I thought A would not be touched.
This seems like an awesome feature, as it reduces recompilation time when A isn’t changed.
Is this a new feature? If so, where can we read up on this and other compilation-time magic that was included?
To my knowledge this has been in VS since version 2005, but perhaps earlier. It only happens when you explicitly reference another project in your solution via the “Projects” tab in the “Add reference” dialog.