COM Register

using System;
using System.Runtime.InteropServices;
using System.Runtime.InteropServices.ComTypes;

namespace comtest
{
    [ComVisible(true)]
    [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
    [Guid("9009311a-c0b2-42a4-8e7c-f42091d71594")]
    public interface ITestEvents {
        void OnEvent();
    }

    [ComVisible(true)]
    [ClassInterface(ClassInterfaceType.AutoDispatch)]
    [ComSourceInterfaces(typeof(ITestEvents))]
    public class ComClass {
        public event Action OnEvent;

        public int Test() {
            return 100;
        }
    }

    class Program
    {
        [DllImport("ole32.dll")]
        static extern int GetRunningObjectTable(uint reserved, out System.Runtime.InteropServices.ComTypes.IRunningObjectTable pprot);

        [DllImport("ole32.dll")]
        static extern int CreateFileMoniker([MarshalAs(UnmanagedType.LPWStr)] string lpszPathName, out System.Runtime.InteropServices.ComTypes.IMoniker ppmk);

        public static void Main(string[] args)
        {
            IRunningObjectTable rot;
            IMoniker mon;

            var obj = new ComClass();

            GetRunningObjectTable(0, out rot);

            CreateFileMoniker("comTestApp", out mon);

            int ROTFLAGS_REGISTRATIONKEEPSALIVE = 1;
            rot.Register(ROTFLAGS_REGISTRATIONKEEPSALIVE, obj, mon);

            System.Threading.Thread.Sleep(3600000); // 1 hour
        }
    }
}