设计模式のMementoPattern（备忘录模式）----行为模式

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MementoPattern
{
    //备忘录模式
    class Program
    {
        static void Main(string[] args)
        {

            Originator o = new Originator();
            o.State = "On";

            Caretaker c = new Caretaker();
            c.Memento = o.CreateMemento();

            o.State = "Off";
            o.SetMemento(c.Memento);

            Console.ReadLine();
        }
    }

    public class Memento
    {
        private string _state;

        public Memento(string state)
        {
            this._state = state;
        }

        public string State
        {
            get { return _state; }
        }
    }

    public class Originator
    {
        private string _state;

        public string State
        {
            get
            {
                return _state;
            }
            set
            {
                _state = value;
                Console.WriteLine("State = " + _state);
            }
        }

        public Memento CreateMemento()
        {
            return (new Memento(_state));
        }

        public void SetMemento(Memento memento)
        {
            Console.WriteLine("Restoring state...");
            State = memento.State;
        }
    }

    public class Caretaker
    {
        private Memento _memento;

        public Memento Memento
        {
            get
            {
                return _memento;
            }
            set
            {
                _memento = value;
            }
        }
    }

}