定义：
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，这样以后可以将对象恢复到原先保存的状态。
类图：
类型：行为型
实例：
打游戏一定要存进度
C++ 实现
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| #include <iostream>
#include <string>
#include <vector>
using namespace std;
class Memo
{
public:
string state;
Memo(string state)
{
this->state=state;
}
};
class Originator
{
public:
string state;
void setMemo(Memo *memo)
{
state=memo->state;
}
Memo *createMemo()
{
return new Memo(state);
}
void show()
{
cout<<state<<endl;
}
};
class Caretaker
{
public:
vector<Memo *> memo;
void save(Memo *memo)
{
(this->memo).push_back(memo);
}
Memo *getState(int i)
{
return memo[i];
}
};
int main()
{
Originator *og=new Originator();
Caretaker *ct=new Caretaker();
og->state="on";
og->show();
ct->save(og->createMemo());
og->state="off";
og->show();
ct->save(og->createMemo());
og->state="middle";
og->show();
ct->save(og->createMemo());
og->setMemo( ct->getState(2) );
og->show();
return 0;
}
|
Python 实现
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| class Originator:
def __init__(self):
self.state = ""
def show(self):
print self.state
def createMemo(self):
return Memo(self.state)
def setMemo(self, memo):
self.state = memo.state
class Memo:
state= ""
def __init__(self, state):
self.state = state
class Caretaker:
memos = []
def save(self, memo):
self.memos.append(memo)
def getMemo(self, index):
return self.memos[index]
if __name__ == "__main__":
og = Originator()
ct = Caretaker()
og.state="on"
og.show()
ct.save(og.createMemo())
og.state="off"
og.show()
ct.save(og.createMemo())
og.state="middle"
og.show()
ct.save(og.createMemo())
og.setMemo(ct.getMemo(2))
og.show()
|
执行结果：
Tips:
备忘录模式的Python实现没有什么特点，在这就不在赘述了。
