Managed COM server and COM client. How to subscribe to events of COM server?

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C#

COM

Hello I wrote a managed COM server and COM client in C#. When I’m trying to get a reference to a COM server in a COM client by using this code.

Type comType = Type.GetTypeFromProgID("My.ComServer", true);
object comObj = Activator.CreateInstance(comType);
var comServer = (ComServer)comObj;

I get a reference to the new object instead of a reference to a registered COM server in ROT. To fix this problem, I use pinvoke CoGetClassObject it works but I have another problem.

private void InitComServer(object sender, RoutedEventArgs e)
        {
            object comServerInstance = null;

            var factory = Ole32NativeMethods.CoGetClassObject(typeof(TestCoClass).GUID, RegistrationClassContext.LocalServer, IntPtr.Zero, typeof(IClassFactory).GUID) as IClassFactory;

            if (factory != null)
            {
                var iid = typeof(ITestInterface).GUID;
                factory.CreateInstance(null, iid, out comServerInstance);
            }

            this.comServer = (ITestInterface)comServerInstance;
        }

I don’t know how to subscribe to events of COM server.

P.S. I attached a small demo application to illustrate this problem.
https://drive.google.com/file/d/0B_irffxq3qZqWEJMTGJHZWhZWTA/view?usp=sharing