Jun 18, 2013 (last update: Jun 18, 2013) Score: (315 votes) It is my first article please consider as a fresh article. By definition Stdafx.h is a precompiled header. Precompiled the word implies that this header file is precompiled (once compiled no need to compile it again). Precompiled Header stdafx.h is basically used in Microsoft Visual Studio to let the compiler know the files that are once compiled and no need to compile it from scratch. For Example: If you are including the below windows header files Code: include include int main /your code return 0; The compiler would always compile this header files from scratch. But if you include include stdafx.h before this includes then the compiler will find the compiled header files from stdafx.h and does not compiled it from scratch. but if compiler doesn't find any compiled header files from stdafx.h then first it compiles that files and then stores its compiled version in stdafx.h. So that it can be use for next time compilation. Code: include stdafx.h include include int main /your code return 0; What are its benefits: Reduces compile time. Reduces Unnecessary Processing. So conclusion is use include stdafx.h where you are actually using the other header files (like windows header files). Otherwise no need to use stdafx.h. And It doesn't mean that you remove it from your project but you may disable this precompiled header from project settings by selecting the file (in which you do not need this stdafx.h) and go to properties of it and find under C+ option -> Precompiled Header and select Use Precompiled Header to No. That's it. Enjoy.
: Guys : beware of the VC6.0 bug in that area: if you created an application using Wizard, you cannot add anything in the stdafx.h despite the comment in it that application should add its own header files here. If you add something the program does not compile!. Hmmm. I don't have that problem here.: If you look closely to Project-> Settings-> Precompiler headers you will see that checkbox Use precompiler header is checked and the name being loaded is stdafx.pch. Instead it should be Automatically use/create checkbox. If it says stdafx.[red]pch[/red], that [italic]is[/italic] a bug. It should say stdafx.[red]h[/red]. Project-> Settings-> Precompiled Headers should look like this:[code] stdafx.h - [ X] [b] Create[/b] precompiled header file. Through Header: [b]stdafx.h[/b] *.cpp - [ X] [b] Use[/b] precompiled header file. Through Header: [b]stdafx.h[/b][/code] The only really important thing is that the file specified under Through Header matches for both the file generating the precompiled header, and the files using the precompiled header. Obviously, stdafx.h is just a convention, you could name the precompiled header Monkey Ass.h if you wanted to. The advantage of using the name stdafx is that (for Visual C+ generated projects) Visual C+ will automatically set the precompiled header directive for newly added files to stdafx.h.
Download Now