C++ – event notifications not received as described

Problem:

• Event notifications (From COM object – Server) are not received as listed in the Sink (class) implementation.

• One event notification is received (Event_one), however, others are not received accordingly

• If order is changed – in IDispatch::Invoke, that is:

  • if Event_one is swapped to Event_two then Event_two notification received but Event_one and others neglected accordingly

Question:

• Better way to implement, IDispatch::Invoke or QI?
• Using the wrong logic or approach?

Note:

• No MFC
• No ATL
• Pure C++
• using message loop: GetMessage()
• STA model ( Coinitialize() )
• Call to IDispatch::Advise successful (HRESULT from call S_OK)
• After above, COM object method calls as normal (with interface pointer)
• Single call to Advise
• Type library generated from MIDL compiler

For instance (example):

Illustration of IDispatch::Invoke – taken from Sink Class:

HRESULT STDMETHODCALLTYPE Invoke(
{
//omitted parameters

// The riid parameter is always supposed to be IID_NULL
        if (riid != IID_NULL)
            return DISP_E_UNKNOWNINTERFACE;

if (pDispParams) //DISPID dispIdMember
    {
        switch (dispIdMember) { 
        case 1:
            return Event_one();
        case 2:
            return Event_two();
        case 3:
            return Event_three();
        default:
            return E_NOTIMPL;
        }
    }
    return E_NOTIMPL;
}

Illustration of QueryInterface:

STDMETHOD (QueryInterface)(
//omitted parameters
{
    if (iid == IID_IUnknown || iid == __uuidof(IEvents))
    {
        *ppvObject = (IEvents *)this;
    } else {
        *ppvObject = NULL;
        return E_NOINTERFACE;
    }
    m_dwRefCount++;
    return S_OK;
};