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Automation Object vs COM Object?

Hi all,

I kind of a newbie on COM/DCOM in Delphi and there are some stuff I

What is the main different between a Automation Object & COM object???
In the
help file it says that COM-objects is "simple, lightweight objects such
as a shell
extension" but I cant see any big different when I create it with the
wizaed in D5? One thing I HAVE noticed is that Automation Objects that
implements interfaces with methods must return HRESULT and a
function return value goes back via a parameter - but this can't be the
only thing that
differs COM Object against Automation Object? I know that Automation
can be an existing application like the MS-Office products but in many
papers about
COM/DCOM there seems to be no different between Automation Object & COM
Object? Is there any interface for Automation Objects that isn't for
"light weight"
COM Objects - please explain to me what this is all about...



Re:Automation Object vs COM Object?

An automation object is a particular flavour of COM object. Your literature
seems to be misleading.

Automation objects, as opposed to other kinds of COM object, have the
following characteristics : a very restricted set of valid types, a kind of
double interface that allows pointerless languages to use them easily, the
ability to be executed from within an executable, the ability to be executed
remotely (so long as DCOM OS extensions are present). There may be others,
but I can't think of any.

Greg Lorriman
Handy, free utils at

For tiny setups see
and if you go for it then mention me.

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