Chapter 21 Multiple Document Interface

The multiple document interface (MDI) in the Microsoft Windows operating system is a user-interface standard for presenting and manipulating multiple documents within a single Windows application. An MDI application has one main window, in which the user can open and work with several documents. Each document appears in its own child window in the main application window. Because each child window has a frame, System menu, Maximize and Minimize buttons, and an icon, the user can control it just as if it were a normal, independent window. The difference is that the child windows cannot move outside the main application window.

This chapter covers the following topics:

The structure of an MDI application

Writing procedures for an MDI application

Controlling the child windows of an MDI application