using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var keyHandlers = new Dictionary<int, Action>(); //would actually be the Keys enum but dotnetfiddle doesn't support winforms

        keyHandlers.Add(0, () => Console.WriteLine("Handler for 0"));

        keyHandlers.Add(2, () => {

            var y = 1;

            Console.WriteLine("Handled 2: value{0}", y);

        });

        keyHandlers.Add(3, PrintHello);

        for( int i = 0; i < 5; i++)

        {

            Console.WriteLine("Event number:{0}", i);

            Action actionToDo;

            bool actionRegistered = keyHandlers.TryGetValue(i, out actionToDo);

            if (actionRegistered)

            {

                Console.WriteLine("  Action was registered");

                actionToDo.Invoke();

            }

        }

    }

    public static void PrintHello()

    {

        Console.WriteLine("Hello World");

    }

}

​

​