Re: COM callback

"Cristian Giannini" <cgv@vialcom.cl> wrote in message 
news:4755b3c1@newsgroups.borland.com...

> it is possible to create a callback from a COM server?

Of course.

> I need to send some data to the client that invoke a COM server.

What exactly are you trying to implement?  Are you having a particular 
problem with it, or just looking for general information?


Gambit 

Hi: it is possible to create a callback from a COM server? I need to send 
some data to the client that invoke a COM server.

Thanks 

"Cristian Giannini" <cgv@vialcom.cl> wrote in message 
news:47569de3@newsgroups.borland.com...

> I like to allow a module (COM server) can tell the client
> (the central application) to lunch another module.

When you create a new COM object, the wizard gives you the option of 
enabling event support for it.  That produces an event interface in your 
Type Library that clients can attach to.  Simply att whatever methods you 
want to that interface.  If you then import the COM object into a client 
project, the import wizard produces a wrapper component that includes those 
events.  Or you can use the TEventDispatcher class to attach to the events 
manually.


Gambit 

Hi: I'm building an application that is divide in 7 modules. Each module is 
COM server that provide functionality to others modules.
Furthermore exists a central application that the only purpose is to lunch 
each module. Each Module can also lunch wichever module directly. The 
problem is when a module lunch other module and then I close the main 
application I get the advertisement that the COM server is in use.
I like to allow a module (COM server) can tell the client (the central 
application) to lunch another module. This is do it by clicking a button on 
the main form of each module.

Can you give any idea please?

Thank you

"Remy Lebeau (TeamB)" <no.spam@no.spam.com> escribió en el
mensaje 
news:4755d908$1@newsgroups.borland.com...
>
> "Cristian Giannini" <cgv@vialcom.cl> wrote in message 
> news:4755b3c1@newsgroups.borland.com...
>
>> it is possible to create a callback from a COM server?
>
> Of course.
>
>> I need to send some data to the client that invoke a COM server.
>
> What exactly are you trying to implement?  Are you having a particular 
> problem with it, or just looking for general information?
>
>
> Gambit
> 

"Cristian Giannini" <cgv@vialcom.cl> wrote in message 
news:4757ea87$1@newsgroups.borland.com...

> OK...thanks. Can I add event support if I previouslly create
> a COM object without checking that box?

Yes, but there are several steps involved.  You have to add a DispInterface 
to the TypeLibrary, add it to the CoClass, and mark it as "Source". 
Then 
you have to implement the IConnectionPointContainer and IConnectionPoint 
interfaces in your COM object's implemantation class (you can use the ATL's 
IConnectionPointImpl and IConnectionPointContainerImpl classes to help you 
with that).  At runtime, your clients will implement the DispInterface on 
their end and register themselves with your IConnectionPoint implementation, 
after which time your COM object can then call the registered methods when 
needed.


Gambit