学步园

备忘录模式（Memento Pattern）又叫做快照模式（Snapshot Pattern）或Token模式，是GoF的23种设计模式之一，属于行为模式。

定义(源于GoF《设计模式》)：在不破坏封闭的前提下，捕获一个对象的内部状态，并在该对象之外保存这个状态。这样以后就可将该对象恢复到原先保存的状态

个人理解

在一个类(发起人)中，需要定义一个变量来存储这个类的某些属性在发生变化前的值，因此可以在Originato中定义一个Memento变量，而省去Caretaker这个类

Code

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

namespace MemoDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            GameRole role = new GameRole(100,10000,1000);

            role.Show();
            role.Store();
            role.Fight();
            role.Show();
            role.Reset();
            role.Show();

        }
    }

    public class GameRole
    {
        public int HP;
        public int Attack;
        public int Defense;
        public Memo memo;

        public GameRole(int _hp, int _attack, int _def)
        {
            this.HP = _hp;
            this.Attack = _attack;
            this.Defense = _def;
        }

        public void Fight()
        {
            Console.WriteLine("战斗结束");
            this.HP = 0;
            this.Attack = 0;
            this.Defense = 0;
        }

        public void Show()
        {
            Console.WriteLine("显示当前状态");
            Console.WriteLine("当前血量{0}", this.HP);
            Console.WriteLine("当前攻击力{0}", this.Attack);
            Console.WriteLine("当前防御力{0}", this.Defense);
            Console.WriteLine();
        }

        public void Store()
        {
            this.memo = new Memo(this.HP, this.Attack, this.Defense);
        }

        public void Reset()
        {
            if(this.memo == null)
            {
                return;
            }

            Console.WriteLine("状态重置");

            this.HP = this.memo.HP;
            this.Attack = this.memo.Attack;
            this.Defense = this.memo.Defense;
        }

    }

    public class Memo
    {
        public int HP;
        public int Attack;
        public int Defense;

        public Memo(int _hp, int _attack, int _def)
        {
            this.HP = _hp;
            this.Attack = _attack;
            this.Defense = _def;
        }
    }

}