设计模式-备忘录模式

在不破坏封装性的前提下, 捕获一个对象的内部状态, 并在该对象之外保存这个状态

备忘录模式

//发起人Originator
class Originator
{
    private string state;
    public string State{get;set;}
    //创建备忘录保存
    public Memento CreateMemento()
    {
        return new Memento(state);
    }
    //恢复数据
    public void SetMemento(Memento memento)
    {
        state = memento.State;
    }
    public void Show()
    {
        Console.WriteLine("State = " + state);
    }
}
//备忘录Memento
//封装保存细节
class Memento
{
    private string state;
    public string State{get;}
    public Memento(string state)
    {
        this.state = state;
    }
}
//管理者Caretaker
class Caretaker
{
    private Memento memento;
    public Memento Memento{get; set;}
}
//Client
Originator o = new Originator();
o.State = "On";
o.Show();

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

o.State = "Off";
o.Show();

o.SetMemento(c.Memento);
o.Show();