Decyphering undocumented COM interfaces

Question

Greetings all,

I have a pointer to a COM object that implements an undocumented interface. I would really, really like to be able to use said interface. All I have is the IID though. Master software analyst Geoff Chappell has documented a host of these undocumented COM interfaces on his site; see IListView for example. Somehow he even managed to get the function names and signatures. How is something like that even possible? Are they guesses?

Can someone point me in the right direction as to how I would go about something like this? I know the risks of using anything undocumented.

EDIT: To elaborate, the object I'm interested in is ExplorerFrame.dll's notoriously undocumented ItemsView. By setting an API hook on CoCreateInstance, I can see that the object is created with a certain undocumented IID as its main interface. I'm assuming this is the interface that through which the control is manipulated, hence my interest in figuring out its members.

Answer 1

If your pointer impls IDispatch (which is quite likely) you can QueryInterface for that and then GetIDsOfNames. You likely end up guessing what interfaces it might use and calling QI just to see what works :)