SOME INFO ABOUT MFC:(I refered some site and got this information)...
MFC is a large and extensive C++ class hierarchy that makes Windows application development significantly easier. MFC is compatible across the entire Windows family. As each new version of Windows comes out, MFC gets modified so that old code compiles and works under the new system. MFC also gets extended, adding new capabilities to the hierarchy and making it easier to create complete applications.
The advantage of using MFC and C++ - as opposed to directly accessing the Windows API from a C program-is that MFC already contains and encapsulates all the normal "boilerplate" code that all Windows programs written in C must contain. Programs written in MFC are therefore much smaller than equivalent C programs. On the other hand, MFC is a fairly thin covering over the C functions, so there is little or no performance penalty imposed by its use. It is also easy to customize things using the standard C calls when necessary since MFC does not modify or hide the basic structure of a Windows program.
The best part about using MFC is that it does all of the hard work for you. The hierarchy contains thousands and thousands of lines of correct, optimized and robust Windows code. Many of the member functions that you call invoke code that would have taken you weeks to write yourself. In this way MFC tremendously accelerates your project development cycle.
MFC is fairly large. For example, Version 4.0 of the hierarchy contains something like 200 different classes. Fortunately, you don't need to use all of them in a typical program. In fact, it is possible to create some fairly spectacular software using only ten or so of the different classes available in MFC. The hierarchy is broken into several different class categories which include (but is not limited to):
Application Architecture
Graphical Drawing and Drawing Objects
File Services
Exceptions
Structures - Lists, Arrays, Maps
Internet Services
OLE 2
Database
General Purpose
We will concentrate on visual objects in these tutorials. The list below shows the portion of the class hierarchy that deals with application support and windows support.
CObject
CCmdTarget
CWinThread
CWinApp
CWnd
CFrameWnd
CDialog
CView
CStatic
CButton
CListBox
CComboBox
CEdit
CScrollBar
There are several things to notice in this list. First, most classes in MFC derive from a base class called CObject. This class contains data members and member functions that are common to most MFC classes. The second thing to notice is the simplicity of the list. The CWinApp class is used whenever you create an application and it is used only once in any program. The CWnd class collects all the common features found in windows, dialog boxes, and controls. The CFrameWnd class is derived from CWnd and implements a normal framed application window. CDialog handles the two normal flavors of dialogs: modeless and modal respectively. CView is used to give a user access to a document through a window. Finally, Windows supports six native control types: static text, editable text, push buttons, scroll bars, lists, and combo boxes (an extended form of list). Once you understand this fairly small number of pieces, you are well on your way to a complete understanding of MFC. The other classes in the MFC hierarchy implement other features such as memory management, document control, data base support, and so on.
To create a program in MFC, you either use its classes directly or, more commonly, you derive new classes from the existing classes. In the derived classes you create new member functions that allow instances of the class to behave properly in your application. You can see this derivation process in the simple program we used in Tutorial 1, which is described in greater detail below. Both CHelloApp and CHelloWindow are derived from existing MFC classes.
Friday, June 22, 2007
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