namespace ConsoleApp4

 {

     class Program

     {

         static void Main(string[] args)

         {

             Mum mum = new Mum();

             Dad dad = new Dad();

             Son son = new Son();

             Sister sister = new Sister();

             mum.TellEat();

             mum.EatDel += son.SonEat;

             mum.EatDel += dad.DadEat;

             mum.EatDel += sister.SisterEat;

             mum.EatDel();

             //最后执行这个委托即可

             Console.ReadKey();

         }

     }

     //定义一个无参无返的委托

     public delegate void HaveEatDel();

     public class Mum

     {

         public void TellEat()

         {

             Console.WriteLine("吃饭了");

         }

         //定义委托实例

         public HaveEatDel EatDel { get; set; }

     }

     public class Son

     {

         public void SonEat()

         {

             Console.WriteLine("知道了，玩完游戏再去");

         }

     }

     public class Dad

     {

         public void DadEat()

         {

             Console.WriteLine("就来！");

         }

     }

     public class Sister

     {

         public void SisterEat()

         {

             Console.WriteLine("一会就来");

         }

     }

 }