Can't compile because Visual Studio is using my DLL

Question

I have a rather large .NET 2.0 solution (151 projects) in Visual Studio 2008. Often times when I do a build (even for just one project) in VS I get an error saying that it can't copy one of my DLL assemblies to the output directory because it is in use. I don't have any other processes running in the background or existing debug sessions going that would be using this assembly. If I open up Process Explorer and do a search for this assembly name Visual Studio (devenv.exe) comes up as the only result. Looking at the results Visual Studio has my assembly loaded as a DLL for some reason. Closing the solution and reopening it doesn't solve the problem. I have to completely exit out of VS altogether to get around this issue which is quite disruptive. Does anyone have any idea what is going on? I'm running on Window 7, I don't think I saw this issue on Windows XP.

I am running Visual Studio 2008 Version 9.0.30729.1 SP. I'm also running ReSharper 6 if that matters.

Answer 1

Does anyone have any idea what is going on? I'm running on Window 7, I don't think I saw this issue on Windows XP.

I run into this problem all the time on Windows XP and its not even localized to Visual Studio 2008. What always works for me is I simply clean all solutions, this gets rid of any file that might be in my system's memory, because of Visual Studio.

Visual Studio keeps any your references in memory, so when one of those references is updated, Visual Studio has to release it from memory. If it really happens more then "once in awhile" then you might look at trying to reduce the number of solutions in your project.