using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading;namespace EventClock{    public class ClassWithDelegate    {         //封装了一个返回值为int的多重委托方法        public delegate int DelegateThatReturns();        public DelegateThatReturns theDelegate;        public void Run()        {            for (; ; )            {                Thread.Sleep(500);                if (theDelegate != null)                {                    //显式调用每个委托方法                    foreach (DelegateThatReturns del in theDelegate.GetInvocationList())                    {                        int result = del();                        Console.WriteLine("Delegates fired! return result: {0}",result);                    }                    Console.WriteLine();                }            }        }    }    public class FirstSubscribe    {        private int myCounter = 0;        public void Subscribe(ClassWithDelegate theClassWithDelegate)        {            theClassWithDelegate.theDelegate += new ClassWithDelegate.DelegateThatReturns(DisplayCounter);        }        public int DisplayCounter()        {            return ++myCounter;        }    }    public class SecondSubscribe    {        private int myCounter = 0;        public void Subscribe(ClassWithDelegate theClassWithDelegate)        {            theClassWithDelegate.theDelegate += new ClassWithDelegate.DelegateThatReturns(Doubler);        }        public int Doubler()        {            return myCounter += 2;        }    }        class Program    {        static void Main(string[] args)        {            ClassWithDelegate theClassWithDelegate = new ClassWithDelegate();            FirstSubscribe fs = new FirstSubscribe();            fs.Subscribe(theClassWithDelegate);            SecondSubscribe ss = new SecondSubscribe();            ss.Subscribe(theClassWithDelegate);            theClassWithDelegate.Run();                        Console.ReadLine();        }    }}