Organization with WinForms

Question

So I've just started developing C# WinForm applications and each project I've been working on seems to be larger and requires more user functionality. If I add all of the functionality to one form, obviously it can get out of control very quickly. My last project I would divide up the functionality into individual Forms, and whenever someone say wanted to perform "Feature1" I would instantiate Feature1 Form and show it as a dialog with the main Form as it's owner (so they couldn't click off it).

I'm just curious of what other methods are out there for keeping code organized within Forms. If you are forced to have tons of features/functionality on a single form is there a good way to keep items organized? I simply hate having a code file with hundreds/thousands of lines long.

The answer may simply be in the design, try to design the UI up front so you can utilize multiple forms?

Another example I faced. I created a Tab Control and had about 5 tabs. Those 5 tabs had tons of features and were all stored in the same CS file. What other options did I have? Create a new custom TabControl class with my specific functionality for that tab in it?

I don't mind reading, so if there are decent articles out there feel free to link them!

Answer 1

The go-to method is a Controller/Presenter. The idea is that the window should only be responsible for actually handling the UI events of its controls, and it should do so by calling methods on a Controller which do the real work for the window. The window can either have the handlers necessary or it may link the UI events directly to Controller methods; the former is usually the easier method, but it can be tempting to sneak in a line of code here or there that really should be in the Controller method. By doing this, you sever the layout and presentation logic in the Form class with the business logic in the Controller.

Mark Hall's suggestion of User Controls is also a good one. By creating UserControl classes for tabs or for common UI control combinations, you sever the logic responsible for laying out that part of the UI from the main form's code, and the control then just "drops in" and the window works with it in a much simpler way. This is a must for implementing custom but reusable controls; the fundamental tenet of DRY is that if you have two lines of code in two different places doing the same job to two different but interchangeable things, those lines of code should be merged into one place.