.NET Windows Forms in a Nutshell

Chapter 3. Forms, Containers, and Applications

Any interactive application must have at least one window through which to present its user interface. In the Windows Forms framework, all such top-level application windows are represented by objects whose types derive from the Form class. As with any user interface element, the Form class inherits from the Control class, but it adds windowing features, such as management of the window border and interaction with the Windows taskbar. All Windows Forms applications have at least one class derived from Form.

In this chapter we will examine the structure of a typical Windows Forms application and the way its constituent forms are created. We will look at the programming model for forms, and the way that the Visual Studio .NET Forms Designer uses this model. We will look in detail at the relationship between a form and the controls it contains, and also at the relationships that can exist between forms. The mechanisms underpinning the automatic layout features described in the previous chapter will be examined, and we will see how to use these to add our own custom layout facilities.

Application Structure

All Windows Forms applications have something in common, regardless of whether they are created with Visual Studio .NET or written from scratch:

• They all have at least one form, the main application window.

• They all need to display that form at start up.

• They must shut down correctly at the appropriate time.

This section describes the basic ...