Re: Need example to remove Object Reference using CComPtr class

"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp>
Thu, 4 Sep 2008 10:14:31 -0400
"Landon" <> wrote in message

Yesterday, I've got a suggestion to use the CComPtr class to remove the
object reference but it still became a quite big question for me because I
don't understand how to use it.

I have gone to MSDN, CodeProject, CodeGuru and somewhere else but I still
having difficulties to understand and implement it.

Does anyone ever use the CComPtr class and have it worked successfully?

When you receive/acquire a COM pointer store it in a CComPtr variable.

// .h file inside your class declaration:
 CComPtr <_Application> m_spApp; // Word::Application object

// .cpp file
STDMETHODIMP CMyWordAddin::OnConnection(IDispatch * Application,
ext_ConnectMode ConnectMode, IDispatch * AddInInst, SAFEARRAY * * custom)
{ // save Application pointer
 m_spApp = CComQIPtr <_Application> (Application);

If you receive an Application* you can assign it directly to m_spApp. But
more often you receive an IDispatch*, which you convert to an Application*
using CComQIPtr (which calls QueryInterface for you).

Then use m_spApp as a pointer to call Application methods. That's really
all you do - the Release of the COM pointer is automatic when it goes out of
scope. I.e., its destructor calls Release().

Scott McPhillips [VC++ MVP]

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