状态(state)模式

           Work work = new Work();
            work.Hour = 10;
            work.WriteProgram();

            work.Hour = 13;
            work.WriteProgram();
            work.Hour = 16;
            work.WriteProgram();

            work.Hour = 25;
            work.WriteProgram();

    /// <summary>
    /// 抽象状态
    /// </summary>
    public abstract class StateJob
    {
        public abstract void WriteProgram(Work work);
    }

    //具体状态
    public class ForenoonState : StateJob
    {
        public override void WriteProgram(Work work)
        {
            if (work.Hour < 12)
                Console.WriteLine("当前时间：‘{0}‘，上午工作时间", work.Hour);
            else
            {
                work.SetState(new RestState()); work.WriteProgram();
            }
        }
    }

    //具体状态
    public class RestState : StateJob
    { 
        public override void WriteProgram(Work work)
        {
            if (work.Hour < 14)
                Console.WriteLine("当前时间：‘{0}‘，午休时间", work.Hour);
            else
            { work.SetState(new AfternoonState()); work.WriteProgram(); }
        }
    }

    //具体状态
    public class AfternoonState : StateJob
    {
        public override void WriteProgram(Work work)
        {
            if (work.Hour < 18)
                Console.WriteLine("当前时间：‘{0}‘，下午工作时间", work.Hour);
            else
            { work.SetState(new SleepState()); work.WriteProgram(); }
        }
    }
    //具体状态
    public class SleepState : StateJob
    {
        public override void WriteProgram(Work work)
        {
            Console.WriteLine("当前时间：‘{0}‘，睡觉时间",work.Hour); 
        }
    }

    //工作类
    public class Work
    {
        public int Hour
        { get; set; }

        public bool finish
        { get; set; }

        private StateJob current;
　　　　 
　　　　 //初始状态
        public Work()
        {
            current = new ForenoonState();
        }
        public void SetState(StateJob s)
        {
            current = s;
        }
        public void WriteProgram()
        {
            current.WriteProgram(this);
        }
    } 

  Context c = new Context(new ConStateB());

            c.Request(); 
            c.Request();
            c.Request(); 

    /// <summary>
    /// 抽象状态
    /// </summary>
    public abstract class State
    {
        public abstract void Handel(Context context);
    }

    /// <summary>
    /// 具体状态 ConcreteSate
    /// </summary>
    public class ConStateA : State
    { 
        public override void Handel(Context context)
        {
            context.State = new ConStateB();
        }
    }

    /// <summary>
    /// 具体状态
    /// </summary>
    public class ConStateB : State
    {
        public override void Handel(Context context)
        {
            context.State = new ConStateA();
        }
    }

    /// <summary>
    /// 维护一个ConcreteSate子类
    /// </summary>
    public class Context
    {
        private State state;

        public Context(State _state)
        {
            this.state = _state;
        } 

        public State State
        { get; set; }

        public void Request()
        {
            Console.WriteLine("当前状态：‘{0}‘", state.GetType().Name);
            state.Handel(this);
        }
    }