Re: IDL -> library -> coclass -> interface declaration

"Igor Tandetnik" <>
Wed, 26 Mar 2008 11:21:04 -0400
Jason S <> wrote:

Hmm. That brings up another question. I know that you can have
interfaces which are automation-compatible but not late-binding

Yes. You can have an interface derived from IUnknown and marked with
[oleautomation] attribute. VB can use these, scripting languages can't.

Does that mean clients that use such interfaces
must figure out how to bind to them at compile-time

Roughly, yes.

or is it possible
to work some magic so that they can handle run-time binding?

You can use ITypeInfo::Invoke. It knows how to build appropriate stack
frames based on TLB description of the interface. There's also an
undocumented DispCallFunc API - see
IDispEventSimpleImpl::InvokeFromFuncInfo in atlcom.h. This one allows
you to provide parameter descriptions manually, if you don't have a TLB
handy. And of course, you can build the stack frame by hand, but that's
not for the faint of heart.
With best wishes,
    Igor Tandetnik

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