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what differences are there between implementation of COM in D4 and D5

we have a COM automation client and server module that of course share a
typelibrary between them.
both work correctly when both are compiled in D4, and both work correctly
when both are compiled in D5.
The server exposes a single automation object.

When the server is compiled in D5 and the client in D4 there is an error in
one of the function calls that returns
an olevariant as a var parameter.
could there be a difference in how either COM or OleVariants are implemented
betwen D4 and D5 that could explain this problem?

 

Re:what differences are there between implementation of COM in D4 and D5


There should be no problems here. What is your error?

--
have fun
Binh Ly
http://www.techvanguards.com

Quote
"Robert Ehteshamzadeh" <r...@Amherst.com> wrote in message

news:3b5d9ecc_2@dnews...
Quote
> we have a COM automation client and server module that of course share a
> typelibrary between them.
> both work correctly when both are compiled in D4, and both work correctly
> when both are compiled in D5.
> The server exposes a single automation object.

> When the server is compiled in D5 and the client in D4 there is an error
in
> one of the function calls that returns
> an olevariant as a var parameter.
> could there be a difference in how either COM or OleVariants are
implemented
> betwen D4 and D5 that could explain this problem?

Re:what differences are there between implementation of COM in D4 and D5


I found the error. It turned out to be that the code didn't check that the
object existed before calling
a method. Problem solved.

But I know that there are differences in implementation of the
Delphi COM/ActiveX framework between versions
and wondered if these could create behaviour differences
when compiled with a different version of Delphi.

I assume your finding is that behavior should not change between versions of
Delphi?

Quote
"Binh Ly" <b...@castle.net> wrote in message news:3b5e2a8f_2@dnews...
> There should be no problems here. What is your error?

> --
> have fun
> Binh Ly
> http://www.techvanguards.com

> "Robert Ehteshamzadeh" <r...@Amherst.com> wrote in message
> news:3b5d9ecc_2@dnews...
> > we have a COM automation client and server module that of course share a
> > typelibrary between them.
> > both work correctly when both are compiled in D4, and both work
correctly
> > when both are compiled in D5.
> > The server exposes a single automation object.

> > When the server is compiled in D5 and the client in D4 there is an error
> in
> > one of the function calls that returns
> > an olevariant as a var parameter.
> > could there be a difference in how either COM or OleVariants are
> implemented
> > betwen D4 and D5 that could explain this problem?

Re:what differences are there between implementation of COM in D4 and D5


COM support in Delphi has not changed much since D4. Just a few minor bug
fixes here and there but thats about it. I believe Borland has concentrated
more in other areas of the product.

What are you looking for specifically?

--
have fun
Binh Ly
http://www.techvanguards.com

Quote
"Robert Ehtesham" <ehtes...@telocity.com> wrote in message

news:3b5e59a9_1@dnews...
Quote
> But I know that there are differences in implementation of the
> Delphi COM/ActiveX framework between versions
> and wondered if these could create behaviour differences
> when compiled with a different version of Delphi.

Re:what differences are there between implementation of COM in D4 and D5


What caused me to write my post was the crippling fear my
employer has about version incompatibilites. Whenever there is some
unobvious problem
with COM/DCOM and different tiers are created with different versions of
Delphi,
bingo - version incompatibility - or DCOM itself,  is the suspect.

My hunch is that this is very, very unlikely - the whole idea of COM is
binary compatability
between languages, compilers and even versions of the generated libraries
themselves.
But I wanted to do some research before I ruled out the possibility
completely -
I figured that there were probably some more obscure features that are
broken between D4 and D5
and now from D5 to D6.

I guess D3 was borland's first cut at COM and a lot of things changed in D4.

Robert Ehteshamzadeh

Quote
Binh Ly <b...@castle.net> wrote in message news:3b5f7fca$1_1@dnews...
> COM support in Delphi has not changed much since D4. Just a few minor bug
> fixes here and there but thats about it. I believe Borland has
concentrated
> more in other areas of the product.

> What are you looking for specifically?

> --

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