Re: a Query regarding COM Server and terminal services

From:

=?Utf-8?B?ZA==?= <d@discussions.microsoft.com>

Newsgroups:

microsoft.public.vc.atl

Date:

Thu, 11 Jun 2009 20:41:01 -0700

Message-ID:

<83658F01-EEF9-44E5-9FCE-A5C1AB26B71F@microsoft.com>

in that case, if we want to fire a callback then all the clients will be
notified
is there any way by which we could differentiate between two clients in the
conncetion point callbacks in server?

am i missing something here?
here is the code that gets generated by wizard for connection point how will
i differentiate between the two clients here.

template<class T>
class CProxy_IAddEvents :
    public IConnectionPointImpl<T, &__uuidof(_IAddEvents)>
{
public:
    HRESULT Fire_ExecuteMe( LONG Result)
    {
        HRESULT hr = S_OK;
        T * pThis = static_cast<T *>(this);
        int cConnections = m_vec.GetSize();

        for (int iConnection = 0; iConnection < cConnections; iConnection++)
        {
            pThis->Lock();
            CComPtr<IUnknown> punkConnection = m_vec.GetAt(iConnection);
            pThis->Unlock();

            _IAddEvents* p_IAddEvents =
reinterpret_cast<_IAddEvents*>(punkConnection.p);
            if (p_IAddEvents != NULL)
                hr = p_IAddEvents->ExecuteMe(Result);

            /*IDispatch * pConnection = static_cast<IDispatch *>(punkConnection.p);

            if (pConnection)
            {
                CComVariant avarParams[1];
                avarParams[0] = Result;
                avarParams[0].vt = VT_I4;
                CComVariant varResult;

                DISPPARAMS params = { avarParams, NULL, 1, 0 };
                hr = pConnection->Invoke(1, IID_NULL, LOCALE_USER_DEFAULT,
DISPATCH_METHOD, &params, &varResult, NULL, NULL);
            }*/
        }
        return hr;
    }
};

regards
--
d

"Brian Muth" wrote:

"d" <d@discussions.microsoft.com> wrote in message
news:612762C3-D067-4BDE-B8DD-260F77AD2B8D@microsoft.com...

hello Brian ,

thanks for your reply. earlier we were using connection points to perform
task.

Why not do it that way?

then later we decided that if we could pass a interface pointer to the COM
server from the client. we would be able to differentiate it.

i have one more concept problem. i have a class which interect with a
service.
now if any of the COM server client connections to the service classs with
IServicePtr ptr(__uuidof(Service))

i have a function in the "IService" interface called
GetInterface(ISomeInterface ** psf)

now in the COM EXE server

CService::GetInterface(ISomeInterface ** psf)
{
return CSomeInterface::CreateInstance(psf);
}

in this case if there are 10 users who create the Service COM object will
have
10 different -2 instance of "CSomeInterface::CreateInstance(psf);" i mean
10
ISomeInterface interface. am i wrong here??

No, you are correct. That is the standard paradigm.

i want to instentiate only ONE "CSomeInterface" Object to be returned

Then change the implementation of CService::GetInterface(ISomInterface
**psf). Perhaps it might look something like:

static ISomInterface *pSingleton = null;

CService::GetInterface(ISomeInterface (** psf)
{
    if (pSingleton == null)
    {
        CSomeInterface::CreateInstance(pSingleton);
    }
    return pSingleton;
}

Howeever, I'd like to ask why? Why do you want the same COM object to be
handed out to all your clients? It can be done, but I suspect there is a
much better way to meet your requirements, which you haven't described.