COM Interfaces

Some important interfaces within COM are:

• IDispatch

  A dispatch interface is used to communicated with a wide variety of components, particularly those written in other languages such as VisualBasic, C++, Java etc.

  Carapace uses a Dispatch interface to communicate with other COM components.

• IUnknown

  All COM interfaces are based upon the Unknown interface. It is this interface which allows a COM client to get different interfaces on a COM object.

• IEnumVARIANT

  This enumerator interface allows objects to offer a sequence of items using a standard interface. The enumerator allows you to work along the sequence accessing each item as required.

Each interface is identified by a GUID. Interfaces also can have a more readable name. In the same way, each object is identified by a GUID as well as usually having a readable name (the ProgID).