Technology

Microsoft Foundation Class Library (MFC)

The Microsoft Foundation Class Library (MFC) is an "application framework" for programming in Microsoft Windows. Written in C++, MFC provides much of the code necessary for managing windows, menus, and dialog boxes; performing basic input/output; storing collections of data objects; and so on. All you need to do is add your application-specific code into this framework. And, given the nature of C++ class programming, it's easy to extend or override the basic functionality the MFC framework supplies.

The MFC framework is a powerful approach that lets you build upon the work of expert programmers for Windows. MFC shortens development time; makes code more portable; provides tremendous support without reducing programming freedom and flexibility; and gives easy access to "hard to program" user-interface elements and technologies, like Active technology, OLE, and Internet programming. Furthermore, MFC simplifies database programming through Data Access Objects (DAO) and Open Database Connectivity (ODBC), and network programming through Windows Sockets. MFC makes it easy to program features like property sheets ("tab dialogs"), print preview, and floating, customizable toolbars.

The Framework

Your work with the Microsoft Foundation Class Library (MFC) framework is based largely on a few major classes and several Visual C++ tools. Some of the classes encapsulate a large portion of the Win32 application programming interface (API). Other classes encapsulate application concepts such as documents, views, and the application itself. Still others encapsulate OLE features and ODBC and DAO data-access functionality.

For example, Win32's concept of window is encapsulated by MFC class CWnd. That is, a C++ class called CWnd encapsulates or "wraps" the HWND handle that represents a Windows window. Likewise, class CDialog encapsulates Win32 dialog boxes.

Encapsulation means that the C++ class CWnd, for example, contains a member variable of type HWND, and the class's member functions encapsulate calls to Win32 functions that take an HWND as a parameter. The class member functions typically have the same name as the Win32 function they encapsulate.