Re: Interface inheritance between different COM modules?

From:

"Igor Tandetnik" <itandetnik@mvps.org>

Newsgroups:

microsoft.public.vc.atl

Date:

Fri, 22 Jun 2007 07:49:23 -0400

Message-ID:

<e0CteNMtHHA.2444@TK2MSFTNGP06.phx.gbl>

"Axel Bock" <axel.bock.news@googlemail.com> wrote in message
news:1182494652.692344.167660@w5g2000hsg.googlegroups.com

I have a - hopefully - simple problem. I need to write an Interface
INT_B in a COM component COM_B, which actually inherits from an
interface INT_A from COM component COM_A.

I try to do this by importlib'ing the COM_A.dll file in the COM_B.idl,
and write the following line:

interface IINT_B : IINT_A { };

Where IINT_A is defined in the COM_A.dll file. Alas I get a MIDL
compiler error: COM_B.idl(31) : warning MIDL2271 : [object] interfaces
must derive from another [object] interface such as IUnknown :
[ Interface 'IINT_A' (IINT_A' ) ].

You need to both import A.idl outside the library block, and importlib
A.tlb (or A.dll) inside the library block.
--
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