c++ - Basic DLL Function -

i'm new world of c , programming generally! trying create simple dll file prints messagebox hello world!

here's cpp

//main.cpp       #include "main.h"  // sample exported function void dll_export somefunction(const lpcstr sometext) {     messageboxa(0, sometext, "dll message", mb_ok | mb_iconinformation); } extern "c" dll_export bool apientry dllmain(hinstance hinstdll, dword fdwreason, lpvoid lpvreserved) {  switch (fdwreason) {     case dll_process_attach:         // attach process         // return false fail dll load         break;      case dll_process_detach:         // detach process         break;      case dll_thread_attach:         // attach thread         break;      case dll_thread_detach:         // detach thread         break; } return true; // succesful } 

and here h

//main.h  #ifndef __main_h__ #define __main_h__  #include <windows.h>  /*  use exported function of dll, include header  *  in project.  */  #ifdef build_dll     #define dll_export __declspec(dllexport) #else     #define dll_export __declspec(dllimport) #endif   #ifdef __cplusplus extern "c" { #endif  void dll_export somefunction(const lpcstr sometext);  #ifdef __cplusplus } #endif  #endif // __main_h__ 

the point once make console loads dll have call function it! how export functions without giving them name load dll in console? if wanna use dll , doesn't know call? or if got exe calling dll e want create custom dll functions called? not hacking porpuses! sorry skills thx

"what if wanna use dll , doesn't know call" - if uses dll, needs know call, there not simple ways around (therefore provide *.h function declarations).

there ways enumerate functions provided dll (see e.g. here: win32 api enumerate dll export functions?), not how dll libraries used.

note can enumerate function names, without header might not easy find out parameters pass each function , type functions returns. can in general done c++ exported functions (the c++ name mangling provides parameter count , type information), not if function exported plain "c" function (where name simple function name without mangling).