Windows Forms

According to Webster,[1] the noun form has nineteen different meanings, none of which is computer related. The closest is definition number ten: "A document with blanks for the insertion of details or information." A Windows Form is a digital analog of a piece of paper used for gathering and displaying information.

[1] Webster's II New College Dictionary (Houghton Mifflin, 2001)

A form may be either the main or subsidiary screen of an application, a dialog box, or a display of graphical output. It may be a single document interface (SDI) application or part of a multiple document interface (MDI) application. Forms typically contain controls that the user interacts with, such as buttons, text boxes, scrollbars, labels, and so on.

In the .NET Framework, the form is encapsulated in a Form class. The Form class is at the heart of almost every .NET Windows application.

The Form object itself is a control that derives from the System.Windows.Forms.Control class (via the classes ScrollableControl and ContainerControl).

This chapter will cover many of the fundamental aspects of Windows Forms, including how to decide between a Windows Forms application and a web application, the different types of available user interfaces and some UI guidelines, how the Forms class is implemented, and how to inherit from forms you create yourself.

Ultimately, every Windows application is implemented by calls to the Windows Application Programming Interface (API). The API consists of C library calls. The .NET Framework wraps these API calls inside well-encapsulated objects, and provides you with a complete object-oriented, type-safe, garbage-collected, managed environment for indirectly manipulating the Windows API.