Passing double datatype from C++ to VB6

"cris.b" <>
7 Aug 2006 02:48:06 -0700
I'm trying tp fire-up an event from a OCX (written & compiled C++
visual VS2003) with a VB6 client.
That event should pass 2 parameter : the firts is a BSTR and the second
is double.
With these parameter types the VB6 client doesn't receive the event!
If I change the second parameter type into a BSTR, the VB6 client
receives event correctly!!!!

Any idea?
I put the C++ code at the end of the message...

Thanks in advice!

------------------- event code ----------------------

    HRESULT Fire_DragEnd(BSTR* PartName, DOUBLE Position)
        CComVariant varResult;
        T* pT = static_cast<T*>(this);
        int nConnectionIndex;
        CComVariant* pvars = new CComVariant[2];
        int nConnections = m_vec.GetSize();

        for (nConnectionIndex = 0; nConnectionIndex < nConnections;
            CComPtr<IUnknown> sp = m_vec.GetAt(nConnectionIndex);
            IDispatch* pDispatch = reinterpret_cast<IDispatch*>(sp.p);
            if (pDispatch != NULL)
                pvars[0] = *PartName;
                pvars[1] = Position;

                DISPPARAMS disp = { pvars, NULL, 2, 0 };

                pDispatch->Invoke(0x4, IID_NULL, LOCALE_USER_DEFAULT,
DISPATCH_METHOD, &disp, &varResult, NULL, NULL);
        delete[] pvars;
        return varResult.scode;


--------------------------- idl ---------------------------
    dispinterface _IVRSAnimationEvents
        methods: ... omissis ...
            [id(4), helpstring("method DragEnd")] HRESULT DragEnd([out]BSTR*
PartName, [out]DOUBLE* Position);

----------------------- event's fire -----------------------
void CVRSAnimationCA5XX::DragEnd()
    BSTR sPN = _bstr_t(sPart2Drag.c_str()).copy();
    DOUBLE dPos = 1500.56;
    Fire_DragEnd(&sPN, dPos);

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