Hello.asm:
include 'win32ax.inc' ; you can simply switch between win32ax, win32wx, win64ax and win64wx here

.code

start:
invoke MessageBox,HWND_DESKTOP,"Hi! I'm the example program!",invoke GetCommandLine,MB_OK
invoke ExitProcess,0

.end start

I have this hello.asm file and I want to include this file in my visual studio c++ code?

The steps are:

- Change assembly to a COFF object file
- Change API references to external implementation links
- Set up the VC++ project to include your object file and link kernel32 and user32
- Add a dummy cpp file to allow the executable to be built
- Declare the entrypoint as public in the FASM object and set the entrypoint to start
- Explicitly define the subsystem in the VC++ project (I chose windows here) to allow correct linking

Attached is an example VS2010 project.

Thanks for your valuable suggestion

func_fasm.asm:

include 'win32ax.inc' ; you can simply switch between win32ax, win32wx, win64ax and win64wx here

.code
proc fun1
invoke MessageBox,HWND_DESKTOP,"Hi! I'm the example program!",invoke GetCommandLine,MB_OK
endp

how to call fun1 function from c++

Similar though easier:

(-Using a normal C++ project)
- Declare the FASM function you want to reference in C++
- Change assembly to a COFF object file
- Export the function for C++ in FASM [note: you have to encode the correct link string; I normally grab this from the error string. This will change for different compilers, architectures and calling conventions]
- Add the FASM object to the link dependencies