Thread: windows programming

hiii,

This is naidu.I am a beginner to VC++ programming.
So please help me by telling the meaning of
"AFX_WINGREET_H__E7D60DA4_9891_11D1_80FC_00C0F6A83 B7F__INCLUDED_".
this is appeared in my "Wingreet.h "header file s first line,when i created my first program "Wingreet" in VC++.

Invariably, header files look like this

Code:

#ifdef SOMETHING
#define SOMETHING
// body of header file goes here
#endif

SOMETHING will not be defined the first time the file is included, so the body of the header file is included, and SOMETHING becomes defined.
If you try and include the file again, then SOMETHING will already be defined and the body of the header file will be skipped (you've already included it)

It basically means you can

Code:

#include "Wingreet.h"
#include "Wingreet.h"

without the compiler complaining about things being redefined or redeclared.

and the actual string is generated by Visual C++ to be guaranteed unique for each generation so you can have identically named but different headerfiles in different applications without clashes.

AFX_<filename>_<GUID>_INCLUDED where GUID is generated by GuidGen (or whatever the Microsoft equivalent is) based on your network card MAC address, a timestamp, and some other stuff.