Re: Why getting 'The value of ESP was not properly... debug error

From:

"Igor Tandetnik" <itandetnik@mvps.org>

Newsgroups:

microsoft.public.vc.atl

Date:

Sun, 16 Jul 2006 11:27:19 -0400

Message-ID:

<#sZvGxOqGHA.4868@TK2MSFTNGP04.phx.gbl>

"Angus Comber" <nospam@gmail.com> wrote in message
news:umcAu%23MqGHA.4960@TK2MSFTNGP04.phx.gbl

"Igor Tandetnik" <itandetnik@mvps.org> wrote in message
news:OxNV#3IqGHA.4508@TK2MSFTNGP04.phx.gbl...

"Angus Comber" <nospam@gmail.com> wrote in message
news:eWwn74CqGHA.2256@TK2MSFTNGP03.phx.gbl

hr = schema->Query(query, (IDispatch**)&resultset);

resultset is like this:

CComQIPtr<ICOMQueryResultSet> resultset;

That's what I thought. You are effectively downcasting from IDispatch to
ICOMQueryResultSet. You cannot do that - you must use QueryInterface to
obtain one interface pointer from another. You need something like this:

CComPtr<IDispatch> resultsetDisp;
schema->Query(query, &resultsetDisp);
CComQIPtr<ICOMQueryResultSet> resultset = resultsetDisp;

--
With best wishes,
Igor Tandetnik

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925