Question

When adding a DLL as a reference to an ASP.Net project, VS2008 adds several files to the bin directory. If the DLL is called foo.dll, VS2008 adds foo.dll.refresh, foo.pdb and foo.xml. I know what foo.dll is :-), why does VS2008 add the other three files? What do those three files do? Can I delete them? Do they need to be added in source control?

Answer 1

Source Control:

Ben Straub said in a comment to this post: The .dll.refresh files should be added to the source control if required, while the .xml, .pdb and of course the .dll files should not be added.

John Rudy explained when to add the .refresh file:

Why is this a good thing (sometimes)? Let’s say you’re in a team environment. Someone checks in code for foo.dll, and your build system builds a new DLL, outputting it in a file share on a server. Your refresh file points to that server copy of the DLL. Next time you build, VS will auto-magically grab the latest and greatest copy of that DLL.

.xml like David Mohundro said:

The xml file is there for XML comments and intellisense. Visual Studio will parse that and display the XML comments that were added when you call methods in those DLLs.

.pdb like David Mohundro said:

The pdb is there for debugging and symbols. If you get an exception thrown from it, you’ll be able to get stacktraces, etc. You’re in control of choosing whether or not the PDB is built.

.refresh from a blog post about .refresh files:

It tells VS where to look for updated versions of the dll with the same base name. They’re text files, you can open them and see the path it’s using.

Their purpose is to prevent you from having to copy new versions yourself. In VS2003, the project file would contain the source location of the reference, but since VS2005 doesn’t use project files for ASP.NET projects, this is the replacement for that particular functionality.