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returning variant array from vb to vc++

Posted: 2002-06-01
By: ArchiveBot
Viewed: 69

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VB6 Code Cache

Title Uploaded Size 9/3/2020 3:45:00 PM 10,922

Passing variant array between vb server and vc++ is noteasy task. I found a technique when i searched for a week on this matarial - how to return variant array from activeX exe(VB) to MFC(VC++).To make easy you , i submit not in exact form what i found on msdn and internet ,but what technique i used and got success.

Original Author: Ashutosh Upadhyay


How to return variant array from VB ActiveX Server (EXE/DLL) to VC++

Step 1. Make a VB ActiveXDll /EXE project

   1.1 - Name your Project and Default Class , We assume Prject name - Project1 and      Class Name - Class1

   1.2 copy and past follwoing function
     public function abc() as Variant
     dim a(10) as long
     a(0) = 10
     a(1) = 13
     a(10) = 67
    end function
   1.3  open file menu ,choose make project1.dll/project1.exe
Step 2. Open A Simple VC++ Project
   2.1 choose MFC application(exe),then,dialog application,then,support automation
   2.2 choose View -> ClassWizard -> Automation tab -> Press Add Class ->     choose From a type library
   2.3 allow MFC to generate wrapper classes for your VB server. We assume name     of Wrapper class genrated by MFC is _Class1
   2.4 in your dialog class ( in ..dlg.h file) , make a variable of your wrapper class
      class YourApplictionDlg : public CDialog
      public :
      _Class1 ashu;

     2.5 open Oninitdialog() function of your dialog (dlg) class and copy following       code in the end of function
      // TODO: Add extra initialization here
      return TRUE;
    2.6 To retrieve the values of array of VB server write followoing code
       in a function, for example in OnOK()

void .......Dlg::OnOK() {
v =;

SAFEARRAY *parray;
parray = v.parray;

short sElem;
long lLb, lUb, l;
long lResult[10];
if (parray == NULL){ // array has not been initialized
if ((parray)->cDims != 1) {// check number of dimensions
MessageBox("Dim <> 1");
TRACE("%d ",parray->cDims);
return ;
TRACE("%d ",parray->cDims);
// get the upper and lower bounds of the array
if (FAILED(SafeArrayGetLBound(parray, 1, &lLb)) ||
FAILED(SafeArrayGetUBound(parray, 1, &lUb))){
MessageBox("Array Bound Failed");
return ;
TRACE(" %d %d ",lLb,lUb);
// loop through the array and put the elements into array lResult
int i=0;
for (l = lLb; l <= lUb; l++) {
if (FAILED(SafeArrayGetElement(parray, &l, &sElem))){
MessageBox("Element failed");
return ; }
TRACE("%d ",sElem);
lResult[i++] = sElem;
///// You can display array in message box
///// To display
CString s;
s.Format("%d %d %d .....  %d", lResult[0],lResult[1],..........,lResult[lUb]);
///////////// delete CDialog::OnOk()
    2.7 Now in your dialog class OnClose or OnCancel function copy following  
    2.8 build your program and run. you may add header file in your      _Class1.h file, if any problem in building.


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