Re: Calling a FreeBASIC-DLL from VB

Am Sun, 16 Mar 2008 13:09:50 +0100 schrieb Wolfgang Enzinger:

> I'm currently trying to write a DLL in FreeBASIC for calling from VB.
> However, VB seems to load the DLL but cannot find my ex****ted procedure
> whatever I try.

OK, got this one solved. For the archives ...

**** <FreeBasic code> **** 

'File: VBTest.bas
#include once "windows.bi"
#include once "win/ole2.bi"

EXTERN "windows-ms"

FUNCTION AddNumbers ( _
  BYVAL operand1 AS INTEGER, BYVAL operand2 AS INTEGER ) _
  AS INTEGER EX****T
RETURN operand1 + operand2
END FUNCTION

FUNCTION UpperCase(BYVAL arg AS ZSTRING PTR) AS BSTR EX****T
DIM res AS BSTR, s AS STRING
s = UCASE(*arg)
res = SysAllocStringByteLen(STRPTR(s), LEN(s))
RETURN res
END FUNCTION

END EXTERN 

**** </FreeBasic code> ****

Compilation:
fbc.exe -dll -ex****t VBTest.bas


**** <VB code> **** 
Option Explicit

Declare Function AddNumbers _
  Lib "VBTest.dll" _
  (ByVal operand1 As Long, ByVal operand2 As Long) _
  As Long
  
Declare Function UpperCase _
  Lib "VBTest.dll" _
  (ByVal s As String) _
  As String

Sub main()
Debug.Print AddNumbers(1, 2)
Debug.Print UpperCase("this is a test")
End Sub

**** </VB code> **** 

> Wolfgang