Make changes to c# program without loosing older code

Question

I'm a hobbyist programmer and I've created an application for my office. Every so often I need to improve the code, add features or fix issues that come up under certain circumstances - I've found bugs or ineffective coding even after 3-4 months of heavy usage of the application. The thing is that whenever I modify the code, visual studio saves the changes. This means that if I want to use the program I'll have to be really fast in coding and debugging or it won't build - and I won't be able to use it... Is there any way to keep the old version of the program without having to save the complete project folder elsewhere? Like creating a new version but keeping the option to go back to the old - working - one...

Answer 1

What you are looking for is called source control.

There are many systems out there, two popular ones are subversion and Git.

Used properly, you will have a full history of each file you have in your project.

Answer 2

There are two other answers here regarding source control at the time I write this, but there is another angle on this as well.

You're executing your production copy from the development directory. Don't do this.

When you have developed the program to a stable version, make a copy of it somewhere else and use that copy. In this way you're free to keep developing on the software without destroying your ability to keep using the existing stable version.

As for source control, you should definitely use that as well if you're not already doing it. It would, among other things, allow you to go back and hotfix the stable version with minor bugfixes while still doing major rewrites of the software, as well as the features others here have mentioned, full history of your project, "unlimited" undo, etc.