passing Safearray to VB

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

From: haglu (tfa613_at_yahoo.de)
Date: 09/04/04 

Date: 4 Sep 2004 08:04:10 -0700

Hello,
I try to pass an array of BSTR to a VB client. When the VB procedure
exits, I get a Firstchance Exception in the Server. I think there is
anything wrong with the memory allocation (Windbg output: ...
ole32!CoTaskMemFree ...). ???? But I cant find the mistake.
Can anybody help?

idl:
HRESULT GetComponentNames([in]BSTR bstrFileName, [out,retval] VARIANT*
pNamesArray);
------------------------------------------------------
CPP Server:
HRESULT CExperiment::GetComponentNames(BSTR bstrFileName, VARIANT*
pNamesArray)
{
        SAFEARRAYBOUND rgaBound[1];
        rgaBound[0].lLbound=0;
        rgaBound[0].cElements = m_ComponentNames.size();
        
        ReadFile(bstrFileName); // read m_ComponentNames

        VariantInit(pNamesArray);
        pNamesArray->vt = VT_ARRAY|VT_BSTR;
        pNamesArray->parray = SafeArrayCreate(VT_BSTR,1,rgaBound);
        if (pNamesArray->parray == NULL)
        { // allocation failed
                return(E_OUTOFMEMORY);
        }
        
        long i = 0;
        for (iter = m_ComponentNames.begin();iter!=m_ComponentNames.end();iter++
)
        {
                CComBSTR bstr = iter->c_str();
                SafeArrayPutElement(pNamesArray->parray,&i, bstr);
                i++;
        }
        
        return S_OK;
}

------------------------------------------------------
VB Client:
Public Sub UpdateComponentNames()
    Dim Experiment As NIRExperiment
    Dim strNames() As String
    
    Dim i As Integer
    
    On Error GoTo err
    Set Experiment = GetExperiment
    strNames = Experiment.GetConstituentNames(m_strFileName)
    ' update names
    ......
Exit sub

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