06170253.txt 17-Jun-00


CALL VO DLL FROM MFC C++

Forum:  CA-Visual Objects 2
Section:  VO Programming
Subj:  use VO DLL under VB

To   : Alberto Plottier, 70501,3327      10/25/99 12:55 PM
From :  Uwe Heyer, 100060,1141            #71992

Alberto,

you are welcome
Please be aware that your function name is case sensitive
e.g. MyFunc() != myfunc() != MYFUNC()
below is a sample how to call a VO DLL from a MFC/C++
  application
Here we have the problem with Name Mangeling / Decoration
I get rid of that with the help of a .DEF file and LIB.EXE
  for creating a import library
The sample shows how to call the VO function with a pointer
  call and call through the linker bind
Please note, this sample is defined as STRICT  (C standard
  call method)
1.) Mit VO eine TEST.DLL erzeugt
FUNCTION TestMe(i1 AS INT, i2 AS INT) AS INT STRICT
RETURN i1 * i2
2.) Mit Edit eine TEST.DEF geschrieben
    LIBRARY TEST.DLL
    EXPORTS
      TestMe
3.) Eine ImportLibray TEST.LIB erzeugt
    LIB /DEF:TEST.DEF
4.) DevStudio aufgestartet
extern "C" int TestMe(int, int);
BOOL CETCanonApp::InitInstance()
{
  typedef int (* dlltest) (int, int);
  dlltest test;
  int i1 = TestMe(3, 2);   // Durch Linker gebunden
  // Uber Funktionspointer
  HINSTANCE hTest = LoadLibrary("Test.dll");
  test =  (dlltest) GetProcAddress(hTest, "TestMe");
  int i2 = test(3, 2);
  FreeLibrary(hTest);
  .....
  return TRUE;
}

Ahoj
    Uwe