using System;

​

public delegate void MyDelegate(string msg);

public class Program

{

    public static void Main()

    {

        MyDelegate del1 = ClassA.MethodA;

        MyDelegate del2 = ClassB.MethodB;

        MyDelegate del = del1 + del2;

        Console.WriteLine("After del1 + del2");

        del("Hello World");

        MyDelegate del3 = (string msg) => Console.WriteLine("Called lambda expression: " + msg);

        del += del3;

        Console.WriteLine("After del1 + del2 + del3");

        del("Hello World");

        del = del - del2;

        Console.WriteLine("After del - del2");

        del("Hello World");

        del -= del1;

        Console.WriteLine("After del1 - del1");

        del("Hello World");

    }

}

​

public class ClassA

{

    public static void MethodA(string message)

    {

        Console.WriteLine("Called ClassA.MethodA() with parameter: " + message);

    }

}

​

public class ClassB

{

    public static void MethodB(string message)

    {

        Console.WriteLine("Called ClassB.MethodB() with parameter: " + message);

    }

}