By Adam Nagy
If you are using the COM interface of e.g. AutoCAD or Inventor from a .NET AddIn or application and you want to be able to find out what properties and methods are available for the object, then here is a nice post which shows excactly that. It works even if your project is not referencing the relevant type library/interop assembly and so you are using late binding:
Obtain Type Information of IDispatch-Based COM Objects from Managed Code
I tested it with both Inventor and AutoCAD and it seemed to work fine - I got back all the items shown under Dynamic View inside the Watch window: