expanding interfaces

[venkman]

I have a newbie COM question relating to updating interfaces. I created a COM object with one interface a while ago. I'd like to expand the object by creating a new interface to the object that inherits from the old. I've tried to update the idl file to do this but am getting compile errors when I add
"INewInterface : IOldInterface" and "interface INewInterface" under the class description section of the idl file.

anybody know what I'm doing wrong?
Thanks,
-Venkman

 

[vishnuprasad]

If u dont break compatibility u can expand them in the existing interface but if u want a new expanded one (which breaks compatibility) then u will have to create a new abstract interface defn and again implement in the class where u want.

 

[venkman]

I appreciate the reply, but I'm still a little confused. It seems you're saying I can't have an interface inherit from another one. That doesn't seem right to me. If that's not what you're saying, then I was looking for some more speciffics on how to go about inheriting from a previous interface. As I said in the original post I thought it would be a simple matter of adding "INewInterface : IOldInterface" to the idl. but doing that doesn't compile.

Thanks again,
Venkman