Replacing WinMain() with main() function in Win32 programs

Question

I searched a little bit on StackOverflow and Google but couldn\'t get the idea. I want to start my application with this type of user programming:

int main()         


        

Answer 1

You can use standard main in a "windows" app (that is, a GUI subsystem Windows application) even with the Microsoft tools, if you add the following to the Microsoft linker options:

/subsystem:windows /ENTRY:mainCRTStartup

Note that this is not necessary for the GNU toolchain.

Still for the Microsoft tools you can alternatively add this to your main file:

#ifdef _MSC_VER
#    pragma comment(linker, "/subsystem:windows /ENTRY:mainCRTStartup")
#endif

@James McNellis tells you how to get the hInstance.

Answer 2

GetModuleHandle(NULL) will give you hInstance. hPrevInstance is always NULL.

Answer 3

hInstance is one exception to the "never use global variables" rule-of-thumb. Normally no variable actually logically has scope that's module-wide. hInstance, however, has by definition exactly module-wide scope, so actually the most logical solution is to make a global variable for it and initialize it in WinMain.

As others have suggested, you can also use GetModuleHandle(NULL).

Answer 4

First, GetModuleHandle(0) provides the executable's module handle, which is the same as the hInstance argument of WinMain.

With the GNU toolchaing (g++ compiler), the standard-conforming code is OK.

The Microsoft toolchain, however, only accepts the standard-conforming code by default for a console subsystem executable. To create a GUI subsystem executable with this non-conforming toolchain, using a standard main, you have to specify a Microsoft runtime library entry point that calls the standard main, namely mainCRTStartup. For a command line invocation that means…

cl myApp.cpp /link /entry:mainCRTStartup /subsystem:windows user32.lib

As a practical matter, for working in the command line you can simply specify the entry point in the LINK environment variable:

set LINK=/entry:mainCRTStartup

…

cl myApp.cpp /link /subsystem:windows user32.lib

Creating a similar standard-conforming setup for Visual Studio is perhaps not desirable, since some Visual Studio project types (mainly MFC) requires use of Microsoft's non-standard WinMain or wWinMain.