If you find yourself supporting a WinForms application, you're likely to notice the tests... or lack thereof. Just because we may not have been so focused on automated tests and continuous integration when WinForms was younger, that doesn't mean we can't introduce them now. Better late than never!
Passing data between two Forms, or any two classes, is a very common issue in C#. If you need to pass data around, there are a few ways to do it. Let's get it to work, and then do it better.