Python: Memento Pattern

GeovinDuMemento.py

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

# 备忘录模式 Memento  Pattern  GeovinDuMemento.py #   class Memento:     def __init__(self, value):         self.state = value       def SetState(self, value):         self.state = value       def GetState(self):         return self.state     class Originator:     def SetState(self, value):         self.state = value       def GetState(self):         return self.state       def CreateMemento(self):         return Memento(self.state)       def SetMemento(self, memento):         print("返回上一状态.")         self.state = memento.GetState()     class Caretaker:     def __init__(self, originatorObj):         self.memento = None         self.origin = originatorObj       def Execute(self):         self.memento = self.origin.CreateMemento()         self.origin.SetState(0)       def Unexecute(self):         self.origin.SetMemento(self.memento)

　　

main.py 调用

?

1 2 3 4 5 6 7 8 9 10 11 12 13

# 备忘录模式 Memento  Pattern   originator = GeovinDuMemento.Originator() originator.SetState(1)   print("状态值为: ", originator.GetState())   caretaker = GeovinDuMemento.Caretaker(originator) caretaker.Execute() print("状态值为: ", originator.GetState())   caretaker.Unexecute() print("状态值为: ", originator.GetState())

　　

输出：

?

1 2 3 4

状态值为:  1 状态值为:  0 返回上一状态. 状态值为:  1