Can we use COM object as reference parameter. Will it cause item leak?

Question

Can we use COM object as reference parameter. Will it cause item leak?

Answer 1

Hello,

You can pass a COM object as a parameter. This doesn't increment the reference counter. Still, you need to determine who - the caller or the callee - is reponsible for releasing it. You may want to read When to release COM objects in Office add-ins developed in .NET.

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Regards from Belarus (GMT + 3),

Andrei Smolin
Add-in Express Team Leader

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Answer 2

Can we use COM object as reference parameter. Will it cause item leak?

Answer 3

I'm sorry, can you provide an example of doing this?

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Regards from Belarus (GMT + 3),

Andrei Smolin
Add-in Express Team Leader

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Answer 4

Andrei already responded - no, it won't. Reference will be to RCW, not to real underlying COM object, so reference count will not inrease on that COM object.

Answer 5

Thanks Andrei and DamianD.

Example:

 

public void outlookApp_ItemSend(object item, ref bool cancel)

{

                  Outlook.MeetingItem currentMeeting = (Outlook.MeetingItem)item;

 Outlook.AppointmentItem appointment = currentMeeting.GetAssociatedAppointment(true);

  Somemethod(ref  appointment ); // Call a method

//In finally block I am releasing this object

}

private void Somemethod(ref Outlook.AppointmentItem objAppointment)

{

                // some operation on objAppointment

                //and I am not releasing it here

}

Is it ok? or will it cause item leak?

Answer 6

Yes, remember just to call Release on both meeting and appointment items.

Answer 7

Thank you for the expplanation. This doesn't cause item leak.

---

Regards from Belarus (GMT + 3),

Andrei Smolin
Add-in Express Team Leader

Please mark answers and useful posts to help other developers use the forums efficiently.