Вариант для реализации других видов ооп в C#

fpcs.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace FpCs
{
    class Program
    {
        static void Main(string[] args)
        {
            var str = "I before inc = ";
            Action<Proto> log = (p) => Console.WriteLine(str + p.I());
            var test = new Proto();
            test.AddBefore(ref test.inc, log);

            test.inc();
            test.inc();
            test.dec();
            test.inc();
            Console.ReadKey();
        }
    }

    public class Proto
    {
        public Proto()
        {
            var i = 0;
            inc = () => i++;
            dec = () => i--;
            I = () => i;

        }
        public Action inc;
        public Action dec;
        public Func<int> I;

        public  void AddBefore(ref Action action, Action<Proto> beforHandler)
        {
            var old = action;
            action = () => { beforHandler(this); old(); };
        }


    }
}