Functions of stdafx. h and stdafx. cpp

What is stdafx. h and stdafx. cpp used? Why must each of my CPP files contain stdafx. h?

Windows and MFC include files are very large, even if there is a quick process Program It takes quite a long time to compile the program. Since each. cpp file contains the same include file, it is silly to process these files repeatedly for each. cpp file.
To avoid this waste, Appwizard works with the visual C ++ compiler as follows:
◎ Appwizard creates the stdafx. h file, which contains all the MFC include files required for the current project file. This file can change with the selected options.
◎ Appwizard, then stdafx. cpp is created. This file is usually the same.
◎ Then Appwizard creates the project file, so that the first compiled file is stdafx. cpp.
◎ When Visual C ++ compiles the stdafx. cpp file, it stores the result in a file named stdafx. PCH. (The extension PCH indicates the precompiled header file .)
◎ When Visual C ++ compiles each subsequent. cpp file, it reads and uses the. PCH file it just generated. Visual c ++ no longer analyzes Windows include files unless you have compiled stdafx. cpp or stdafx. h.
This technology is very sophisticated. Don't you think so? (Also, Microsoft is not the first company to adopt this technology, Borland is .) In this process, you must follow the following rules:
◎ Any. cpp file you write must first contain stdafx. h.
◎ If you have a majority of. cpp files in the project file that require. H files, add them to stdafx. H (back) and pre-compile stdafx. cpp.
◎ Because the. PCH file has a lot of symbolic information, it is the largest file in your project file.
If your disk space is limited, you want to delete the. PCH file from the project file you have never used. They are not required when the program is executed, and they are automatically re-established as the project file is re-established.

This article from the csdn blog, reproduced please indicate the source: http://blog.csdn.net/northplayboy/archive/2006/08/25/1118062.aspx