How does the .net framework nest forms in classes. (vb.net)

Question

If I look at some classes in the framework, using reflector, I can see that forms and user controls are made private and nested into a parent class.

For instance, I have a control which makes use of pop-up form that is specific to that control. At the moment, I make the pop-up form friend accessible. If I wanted to do it the framework way, I'd make it private and nest it into the control class. If I do this, however, I can no longer use the ide to design the form and I get errors when I try to compile. So, I have 2 questions:

(1) Do Microsoft do something at the last minute to nest all things private?

(2) Is their way the preferred way or should I stick to my friend accessors?

Answer 1

The nested form is better, because it enforces correct encapsulation and means the final control will end up in one nice neat package for distribution. If neither of those are a concern for you keep doing it your way. But if you want to at least try nesting the class, you can do something like this:

1. Use the designer to build your nested form outside the class as your normally would.
2. Add a second empty form as a private nested form as they do in the CLR examples with the same name as the form you built in step 1.
3. Migrate the code from *.designer.vb or *.designer.cs for your first form to the constructor for your 2nd form. It'll mostly be just a big copy/paste.
4. Remove the form from step 1. You might want preserve by moving it to a separate class library project so you can use when you need to make changes.