Question

We have an application which is also a COM server and can run either as standalone or automated by a COM client.

The COM Class is declared in the following way:

type
  TCommandApp = class(TAutoObject, IConnectionPointContainer, ICommandApp)

And the Initialization part is as follows:

TAutoObjectFactory.Create(ComServer, TCommandApp, Class_CommandApp, 
                          ciSingleInstance, tmApartment);

Which creates an instance of TCommandApp. The question is how do I reference the instance of TCommandApp created by TAutoObjectFactory? (Call its methods etc).

Answer 1

If you want to create TCommandApp instances the same way COM does, then you should call the factory’s CreateInstance method, which comes from the IClassFactory interface.

var
  Factory: IClassFactory;
  App: ICommandApp;

Factory := TAutoObjectFactory.Create(...);
OleCheck(Factory.CreateInstance(nil, ICommandApp, App));

Alternatively, you can call the constructor directly:

var
  Factory: TComObjectFactory;
  App: TCommandApp;

Factory := TAutoObjectFactory.Create(...);
App := TCommandApp.CreateFromFactory(Factory, nil);