using System;

public class Program

{

    public static void Main()

    {

        MyClass2 class2 = new MyClass2();

        Logger1 log1 = new Logger1();

        class2.Log += log1.Log;

        Logger2 log2 = new Logger2();

        class2.Log += log2.Log;

        class2.DoSomeProcess();

    }

    public class MyClass2

    {

        public delegate void LogHandler(string message);

        public LogHandler Log;

​

        public void DoSomeProcess()

        {

            Log("Process Started");//class is not aware of logging implementation

            /* Do the tasks **/

            Log("Process Completed");//class is not aware of logging implementation

        }

    }

​

    public class Logger1

    {

        public void Log(string message)

        {

            Console.WriteLine("Logger 1 (Disk) - "+message);

        }

    }

    public class Logger2

    {

        public void Log(string message)

        {

            Console.WriteLine("Logger 2 (DB or web)- "+message);

        }

    }

}