DLL Question

[Guest]

Hello everyone. I'm new to PB and have a quick question about creating a stdcall wrapper DLL for an existing cdecl DLL.

Ok, so I have a function in a cdecl DLL defined in its documentation as such:

int SN_SetBoardWindow(
HWND hwnd,
BOOL bResize,
int board
);

I create a new PB DLL and declare this function as:

DECLARE FUNCTION SN_SetBoardWindow CDECL LIB "mid2250.dll" ALIAS "SN_SetBoardWindow" (BYVAL hwnd AS DWORD, BYVAL resize AS LONG, BYVAL boardnum AS LONG) AS LONG

I then create a new function in my new DLL:

FUNCTION PT_SetBoardWindow SDECL ALIAS "PT_SetBoardWindow" (BYVAL hwnd AS LONG, BYVAL resize AS LONG, BYVAL boardnum AS LONG) EXPORT AS LONG
FUNCTION = SN_SetBoardWindow(CDWD(hwnd),resize,boardnum)
END FUNCTION

Am I on the right track in using the declare and a new sdecl function? If so, then can someone tell me why this function returns a 'bad dll calling convention' in VB6?

Thanks in advance for any tips/suggestions/help that anyone may give...


Jon

[José Roca]

If so, then can someone tell me why this function returns a 'bad dll calling convention' in VB6?

Because VB6 doesn't understand the PB syntax. Just remove SDECL. STDCALL is the default calling convention used by PB if you don't specify one.

[Michael Mattias]

Besides, you can't export a function compiled as a STDCALL and it expect to work if the caller thinks (via its DECLARE or equal) that it is CDECL!!!

(I believe the code for a stack fault GPF is 0x0000000A)

MCM

[Mike Doty]

Agree with Jose. Here would be the code in VB. Got rid of ALIAS using all upper case.

Option Explicit
Private Declare Function PT_SETBOARDWINDOW Lib "TEST.DLL" (ByVal hwnd As Long, ByVal resize As Long, ByVal boardnum As Long) As Long
Private Sub Form_Load()
  Dim L As Long, resize As Long, boardnum As Long
  L = PT_SETBOARDWINDOW(hwnd, resize, boardnum)
End Sub