Subj : Re: 32 bit Application calling a procedure inside a 32 bit DLL without link to it.
To   : borland.public.cpp.borlandcpp
From : "Ed Mulroy [TeamB]" <dont_email_me@bitbuc.ket>
Date : Fri Jan 30 2004 08:54 am

Do not declare the function pointer as FARPROC.  Either cast the lvalue to
FARPROC or do the more complex job of casting the return value of
GetProcAddress to the pointer's type.  I prefer casting the lvalue.

In either of C or C++ you can call the function pointer in code as if it
actually were the function.

Here is a working example.  If you want to build it from the command line a
command to do so could be:

    bcc32 -WR progname.cpp

  ----------------
  #include <windows.h>

  int WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
    {
    HINSTANCE hlib;
    int (WINAPI *mbox)(HWND, LPCTSTR, LPCTSTR, UINT);

    hlib = LoadLibrary("user32.dll");

    if (hlib)
        {
        (FARPROC) mbox = GetProcAddress(hlib, "MessageBoxA");
        mbox(HWND_DESKTOP, "Here I am!", "MessageBox Func", MB_OK);
        FreeLibrary(hlib);
        }

    return 0;
    }
  ----------------

I know of no practical way to call a 32 bit function from within a 16 bit
application other than to write a 32 bit application and have the 16 bit one
tickle it in a manner that the 32 bit one knows is to call that function,
perhaps with a window message. In particular thunks vary greatly across the
various versions of Windows and can be impossible to debug.

..  Ed

> akuma wrote in message
> news:401a44c9@newsgroups.borland.com...
> Hi, I want to call a dll function dynamicly just if the dll file
> exist. The following is what I want to do:
>
> HINSTANCE hlib;
> FARPROC proc1;
> hlib = LoadLibrary("mydll.dll");
>
> if (hlib) //the library exists
> {
>  proc1 = GetProcAddress(hlib, "myfunc");
>
>  //need to call the procedure proc1
>  //I can't found any API can do this like CallProc32W or
> CallProcEx32W
>  //which designed for 16 bit application to call a 32 bit dll
>  //So, I would like to know which API and how to do this if
>  //myfunc have the prototype:
>  //int myfunc(int para1, LPSTR para2);
>  //...
>
>  FreeLibrary(hlib);
> }

.