call DLL

[Denyson]

I made a DLL (IMPCAR.DLL) using Microsoft Visual C++ 6.0. Now, I´m trying to call the DLL from the Visual Basic 6.0.
My DLL only has an exported function:

extern "C" _declspec(dllexport) icPar *IMPCAR(icPar *ParGlobal);

where:
icPar is a struct.

Please, anybody could me give an example how to declare and call this function from the IMPCAR.DLL?

Thanks

 

[Zyrenthian]

I dont know if you have yet, but the DLL written in VC must have a .def file

(side note... the ; behaves like a comment in the .def file)

***************************************************
; sample .def file
LIBRARY <dll name without the .dll extention and no &quot;<&quot; or &quot;>&quot;>

CODE PRELOAD MOVEABLE DISCARDABLE
DATA PRELOAD MOVEABLE

EXPORTS
IMPCAR

***************************************

This will export the IMPCAR function.

NEXT, with a struct, there MAY be padding issues so make sure there is a 1 to 1 correspondence in the size of the struct defined in C++ and your TYPE defined in VB.

in VB you will want to add:

PRIVATE DECLARE FUNCTION IMPCAR LIB &quot;YOUR_DLL.dll&quot; Alias &quot;IMPCAR&quot;(byVal icPar as YOUR_TYPE) as YOUR_TYPE

*****************************

There may be a few bugs in it but this should get you well on your way into incorporating the dll into VB

Matt