when you use disinterface, you eliminate the first two steps associated
with IDispatch.The automation controller does not have to call GetIDsOfNames,
and the server does not have to respond with the dispid of the method in question. Instead, the dispid is determined at compile time.At runtime, the client program simply calls Invoke with the predetermined
dispid.
Dispinterfaces are for client convenience only, You do not actually
implement a dispinterface on the server.
From <<DELPHI COM PROGRAMMING>>
