How to call functions from someone else's DLL?

Question

Java

I have someone else's dll. Also there is an example on VB6.0 of usage of this dll. dll is not a COM server.
I eventually need to use jni to call this dll from java.
But how to call this dll from c++ to write a jni wrapper?

Answer 1

Load the DLL, find the functions you need and call them :-)
Very schematically, something like this:

// указатель на функцию, которая принимает параметр char* и возвращает int
typedef int  (__cdecl *_your_function)(char *auth_st);
_your_function YourFunction;

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
    HINSTANCE hLib = LoadLibrary("Path_to_DLL");
    YourFunction = (_your_function)GetProcAddress((HMODULE)hLib, "Your_Function_name");
    if(YourFunction  == NULL) {
        //something wrong
    }
    int res = YourFunction ("some string");
}

Answer 2

The only thing in my case in the ad
replaced __cdecl*with __stdcall*
and everything worked.