Design pattern for a single form Windows Forms application

Question

My app is expanding, but the reqs dictate that there should be only one window open at all times, think of Nodepad where there is a menu, with each menu item different functionality but only one window open at all times as opposed to Excel where a user may have few windows open at once.

So in terms of Windows forms, I was thinking of placing a form within a main form. Then i could load an embedded form needed depending on the user menu choice. OR I could be adding controls to the main form (and their events dynamically depending on the user menu choice). I would use a presenter class for that.

That's just two solution I would use. Do you guys have any tips/experience on how to do it better?

I realize now that I would have to re-write parts of my app, but let's pretend i am starting from scratch.

Answer 1

Don't embed Forms, it's not what Forms are for. And it's not necessary.

Put the UI of your modules/sections on UserControls. That keeps it nice and modular and you keep your options open: those UserControls can be directly embedded (1 at a time) in the MainForm or in MDI ChildWindows or in TabPages or ...

Use a Base UserControl (Visual Inheritance) and/or a Interface to implement common functionality.

Answer 2

If your requirements are "one window - multiple functionallity" I would certainly go for a composable UI style of development. The Smart Client Software Factory is a good starting point imo.

Answer 3

It sounds like what you are describing is Multiple-Document Interface (MDI) Applications. Fortunately, there is great support for MDI in WinForms. Here's a quick intro.