Re: Access violation calling auto generated tlh function.

From:

"Igor Tandetnik" <itandetnik@mvps.org>

Newsgroups:

microsoft.public.vc.atl

Date:

Fri, 22 Feb 2008 08:41:10 -0500

Message-ID:

<uL0UXiVdIHA.4968@TK2MSFTNGP02.phx.gbl>

"spforeman" <google@sforeman.com> wrote in message
news:cdf3d7c4-1104-45f6-a6a0-aed1ea9f269e@j28g2000hsj.googlegroups.com

I'm having a problem with a function call causing an access
violation. The function is a COM function call generated as part of
the #import directive. I'm using VC6.

// Event Handler
HRESULT __stdcall CBHSinkObj::OnBHMoveError(struct _clsErrors **
pErrorStruct)
{
short errorCode = (*pErrorStruct)->GetErrorCode(); // crash occurs
within GetErrorCode()

I bet the parameter you really get in your error handler is an
IDispatch* pointer, not _clsErrors* pointer. Declare it as such, then
QueryInterface for _clsErrors. Isn't there something like _clsErrorsPtr
declared in the TLH? Just assign to a variable of that type, the
constructor does QueryInterface for you.
--
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