【C#设计模式(19)——备忘录模式(MementoPattern)】

前言

备忘录模式：将想要备份的信息交给备忘录对象来管理。通过设置初始、备份、修改、恢复等状态展示备忘录模式的使用。

代码

//备忘录类
public class Memento
{private string state;public string State { get=>state;}public Memento(string state){this.state = state;}
}
//发起者类
public class Originator
{private string state;public string State { get => state; set => state = value; }public Memento CreateMemento(){return new Memento(state);}public void RestoreMemento(Memento memento){this.state = memento.State;}
}//管理者类
public class CareTaker
{private Memento memento;public Memento Memento { get => memento; set => memento = value; }
}/** 行为型模式：Behavioral Pattern* 备忘录模式：Memento Pattern*/
internal class Program
{static void Main(string[] args){Originator originator = new Originator();CareTaker taker = new CareTaker();//设置初始状态originator.State = "init state";Console.WriteLine($"初始状态：{originator.State}");//保存taker.Memento = originator.CreateMemento();//修改originator.State = "update state";Console.WriteLine($"修改状态：{originator.State}");//恢复originator.RestoreMemento(taker.Memento);Console.WriteLine($"恢复状态：{originator.State}");Console.ReadLine();}
}

运行结果