This chapter introduces the Microsoft Foundation Class (MFC) Library version 6.0 Multiple Document Interface (MDI) application and demonstrates how it reads and writes its document files. The MDI application appears to be the preferred MFC library program style. It's the AppWizard default, and most of the sample programs that come with Microsoft Visual C++ are MDI applications.
In this chapter, you'll learn the similarities and differences between Single Document Interface (SDI) and MDI applications, and you'll learn how to convert an SDI application to an MDI application. Be sure you thoroughly understand the SDI application described in Chapter 17 before you attack the MDI application in this chapter.