Dunk

using System.Collections.Generic;
using System.Text;

namespace DesignModelTest.狀態
{
    /// <summary>
    /// 抽象類別:狀態
    /// </summary>
    public abstract class State
    {
        public abstract void WriteSeason(Season s);
    }
    /// <summary>
    /// 實做狀態:春天
    /// </summary>
    public class Spring : State
    {
        public override void WriteSeason(Season s)
        {
            if (int.Parse(s.month) < 4 && int.Parse(s.month)>=1)
            {
                Console.WriteLine("春天到了");
            }
            else
            {
                s.SetState(new Summer());
                s.WriteSeason();
            }
        }
    }
    /// <summary>
    /// 實做狀態:夏天
    /// </summary>
    public class Summer : State
    {
        public override void WriteSeason(Season s)
        {
            if (int.Parse(s.month) < 7 && int.Parse(s.month)>=4)
            {
                Console.WriteLine("夏天到了");
            }
            else
            {
                s.SetState(new Fall());
                s.WriteSeason();
            }
        }
    }
    /// <summary>
    /// 實做狀態:秋天
    /// </summary>
    public class Fall : State
    {
        public override void WriteSeason(Season s)
        {
            if (int.Parse(s.month) < 10 && int.Parse(s.month) >= 7)
            {
                Console.WriteLine("秋天到了");
            }
            else
            {
                s.SetState(new Winter());
                s.WriteSeason();
            }
        }
    }
    /// <summary>
    /// 實做狀態:冬天
    /// </summary>
    public class Winter : State
    {
        public override void WriteSeason(Season s)
        {
            if (int.Parse(s.month) <= 12 && int.Parse(s.month) >= 10)
            {
                Console.WriteLine("冬天到了");                
            }
            else
            {
                s.SetState(new Spring());
                s.WriteSeason();
            }
        }
    }
    /// <summary>
    /// 維護狀態子類別的實例,定義現在的狀態
    /// </summary>
    public class Season
    {
        //目前狀態
        private State currentstate;        
        private string _month;
        public Season()
        {
            //設定初始狀態為春天
            currentstate = new Spring();
        }
        public string month
        {
            get { return _month; }
            set { _month = value; }
        }
        /// <summary>
        /// 設定目前狀態.
        /// </summary>
        /// <param name="inputstate">The inputstate.</param>
        public void SetState(State inputstate)
        {
            currentstate = inputstate;
        }
        /// <summary>
        /// 實現狀態子類別中要進行的動作:WriteSeason.
        /// </summary>
        public void WriteSeason()
        {
            currentstate.WriteSeason(this);
        }
    }
}

            //初始狀態為春天 狀態順序為春->夏->秋->冬->春....
            DesignModelTest.狀態.Season currentseason = new DesignModelTest.狀態.Season();
            currentseason.month = "1";
            currentseason.WriteSeason();
            currentseason.month = "4";
            currentseason.WriteSeason();
            currentseason.month = "8";
            currentseason.WriteSeason();            
            currentseason.month = "10";
            currentseason.WriteSeason();
            currentseason.month = "3";
            currentseason.WriteSeason();
            Console.Read();
            #endregion