《大话设计模式》学习笔记12：状态模式

    public abstract class State
    {
        public abstract void WriteProgram(Work work);
    }

    public class ForenoonState:State
    {
        public override void WriteProgram(Work work)
        {
            if(work.Hour<12)
            {
                Console.WriteLine("当前时间：{0} 上午工作，精神百倍", work.Hour);
            }
            else
            {
                work.SetState(new NoonState());
                work.WriteProgram();
            }
        }
    }

    public class NoonState:State
    {
        public override void WriteProgram(Work work)
        {
            if(work.Hour<13)
            {
                Console.WriteLine("当前时间：{0} 饿了，午饭；犯困，午休", work.Hour);
            }
            else
            {
                work.SetState(new AfterNoonState());
                work.WriteProgram();
            }
        }
    }

    public class SleepingState:State
    {
        public override void WriteProgram(Work work)
        {
            Console.WriteLine("当前时间：{0} 太困了，睡着了", work.Hour);
        }
    }

    public class Work
    {
        private State state;
        public Work()
        {
            state = new ForenoonState();
        }
        public int Hour { get; set; }
        public void SetState(State state)
        {
            this.state = state;
        }
        public void WriteProgram()
        {
            state.WriteProgram(this);
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            Work work = new Work();
            work.Hour = 9;
            work.WriteProgram();
            work.Hour = 12;
            work.WriteProgram();
            work.Hour = 19;
            work.WriteProgram();
        }
    }