Message Maps
Encyclopedia
Message Maps - the Microsoft Foundation Class Library
message map facility.
Microsoft Windows
implements what are essentially virtual functions in window classes using its messaging facility. Due to the large number of messages involved, providing a separate virtual function for each Windows message results in a prohibitively large vtable.
MFC provides an alternative to the switch statement used in traditional Windows programs to handle messages sent to a window. A mapping from messages to member-functions may be defined so that when a message is to be handled by a window, the appropriate member function is called automatically. This message-map facility is designed to be similar to virtual functions but has additional benefits not possible with C++
virtual functions.
Message Maps, maps the user action in to the appropriate MFC class functions to handle it. The MFC Class which can handle message should be member of CCmdTarget, (i.e) it should be hierarchically derived from CCmdTarget.
The advantage of Message Map is the same action can be mapped to more than one MFC class function.
It is similar to handling the messages in SDK application using WndProc callback functions, but in MFC with the help OOPS concepts
Microsoft Foundation Class Library
The Microsoft Foundation Class Library is a library that wraps portions of the Windows API in C++ classes, including functionality that enables them to use a default application framework...
message map facility.
Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
implements what are essentially virtual functions in window classes using its messaging facility. Due to the large number of messages involved, providing a separate virtual function for each Windows message results in a prohibitively large vtable.
MFC provides an alternative to the switch statement used in traditional Windows programs to handle messages sent to a window. A mapping from messages to member-functions may be defined so that when a message is to be handled by a window, the appropriate member function is called automatically. This message-map facility is designed to be similar to virtual functions but has additional benefits not possible with C++
C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...
virtual functions.
Message Maps, maps the user action in to the appropriate MFC class functions to handle it. The MFC Class which can handle message should be member of CCmdTarget, (i.e) it should be hierarchically derived from CCmdTarget.
The advantage of Message Map is the same action can be mapped to more than one MFC class function.
It is similar to handling the messages in SDK application using WndProc callback functions, but in MFC with the help OOPS concepts