My team is currently locked into using a tool we dislike that takes the form of a Eclipse plugin and a .jar; the plugin gives us a button to quickly run a single file's code (via invoking the main .jar and passing to it the current file). We want to move to C#.net.  Is there any way to get Visual Studio to replicate this behavior? Obviously we could put each runnable class into its own project in our solution, but that requires checking a lot of project files into source control. Ideally we'd have a main() method in each file and could tell visual studio to run just that file for development purposes, while the finished software would be run from a single entry point using command-line parameters.(I don't want to give too much information here regarding the purpose of the software, so please just accept that the current setup makes a lot of sense for what we're doing and changing it too much would be rejected by management.) 
How to port this architecture to .net?
c#;architecture;visual studio
What you are describing should be covered by a unit testing framework (to test your different classes in isolation).nUnit supports categories, allowing you to selectively run sets of unit tests as needed.