例子

打牌（斗地主规则） 初始钱50 赢牌对面扣钱 地主赢扣20（地主40块） 农民赢扣20(农民一人10块)

    public abstract class AbsMediator
    {
        public abstract void Register(Person obj);

        /// <summary>
        /// 赢牌
        /// </summary>
        /// <param name="obj"></param>
        public abstract void HuCard(Person obj);
    }

    public abstract class Person
    {
        protected AbsMediator AbsMediator { get; set; }

        public Person(string name, PersonType personType)
        {
            Name = name;
            PersonType = personType;
            Money = 100;
        }

        public void SetMediator(AbsMediator mediator)
        {
            AbsMediator = mediator;
        }

        public string Name { get; }
        public PersonType PersonType { get; }
        public int Money { get; set; }

        public void HuCard()
        {
            AbsMediator.HuCard(this);
        }

        public abstract void ReceiveHuCard(Person person);


        protected void AddQian(Person huPerson)
        {
            if (huPerson.PersonType == PersonType)
            {
                if (PersonType == PersonType.农民)
                {
                    Money += 10;
                }
                else if (PersonType == PersonType.地主)
                {
                    Money += 40;
                }
            }
        }

        protected void KouQian(Person huPerson)
        {
            if (huPerson.PersonType == PersonType.农民)
            {
                Money -= 20;
            }
            else if (huPerson.PersonType == PersonType.地主)
            {
                Money -= 20;
            }
        }
    }

    public enum PersonType
    {
        地主 = 0,
        农民 = 1
    }

    public class NoMingPerson : Person
    {
        public NoMingPerson(string name) : base(name, PersonType.农民)
        {
        }

        public override void ReceiveHuCard(Person person)
        {
            AddQian(person);
            if (person.PersonType != PersonType.农民)
            {
                KouQian(person);

                Console.WriteLine("地主赢啦，农民扣钱------还剩" + Money + this.Name);
            }
        }
    }

    public class DizhuPerson : Person
    {
        public DizhuPerson(string name) : base(name, PersonType.地主)
        {
        }

        public override void ReceiveHuCard(Person person)
        {
            AddQian(person);
            if (person.PersonType != PersonType.地主)
            {
                KouQian(person);

                Console.WriteLine("农民赢啦，地主扣钱------还剩" + Money + this.Name);
            }
        }
    }

    public class DouDiZhuMediator : AbsMediator
    {
        private List<Person> colleagues = new List<Person>();

        public override void Register(Person obj)
        {
            if (!this.colleagues.Contains(obj))
            {
                this.colleagues.Add(obj);
                obj.SetMediator(this);
            }
        }

        public override void HuCard(Person obj)
        {
            foreach (var item in this.colleagues)
            {
                item.ReceiveHuCard(obj);
            }
        }
    }


    class Program
    {
        static void Main(string[] args)
        {
            DizhuTest();

            // NongmingTest();
        }

        private static void NongmingTest()
        {
            var doudizhu = new DouDiZhuMediator();

            var dizhu = new DizhuPerson("地主");
            var nongminga = new NoMingPerson("A农民");
            var nongmingb = new NoMingPerson("B农民");
            doudizhu.Register(dizhu);
            doudizhu.Register(nongminga);
            doudizhu.Register(nongmingb);

            nongminga.HuCard();

            Console.WriteLine(nongminga.Money + "," + nongmingb.Money);
        }

        private static void DizhuTest()
        {
            var doudizhu = new DouDiZhuMediator();

            var dizhu = new DizhuPerson("地主");
            var nongminga = new NoMingPerson("A农民");
            var nongmingb = new NoMingPerson("B农民");
            doudizhu.Register(dizhu);
            doudizhu.Register(nongminga);
            doudizhu.Register(nongmingb);

            dizhu.HuCard();

            Console.WriteLine(dizhu.Money);
        }
    }