备忘录模式

《大话设计模式》

备忘录：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。这样以后就可将该对象恢复到原先保存的状态

//memo.h#ifndef _MEMO_H_#define _MEMO_H_#include <iostream>using namespace std; class RoleStateMemento{public:RoleStateMemento(int tvit, int tatk, int tdef):vit(tvit), atk(tatk), def(tdef){ cout << "In RoleStateMemento's constructor" << endl; }RoleStateMemento(const RoleStateMemento &roleState):vit(roleState.vit), atk(roleState.atk), def(roleState.def){ cout << "In RoleStateMemento's copy constructor" << endl; }~RoleStateMemento(){cout << "In RoleStateMemento's deconstructor" << endl;  } int getVitality();void setVitality(int vit);int getAttack();void setAttack(int atk);int getDefense();void setDefense(int def);private:int vit;int atk;int def; }; class GameRole{public:int getVitality();void setVitality(int vit);int getAttack();void setAttack(int atk);int getDefense();void setDefense(int def);void StateDisplay();void GetInitState();void Fight();RoleStateMemento *SaveState();void RecoveryState(RoleStateMemento *memento); private:int vit;int atk;int def;};class RoleStateCaretaker{public:RoleStateCaretaker():memento(NULL){}RoleStateMemento *getMemento();void setMemento(RoleStateMemento *mem); private:auto_ptr<RoleStateMemento> memento; }; #endif

//memo.cpp#include "memo.h"int GameRole::getVitality(){return this->vit;}void GameRole::setVitality(int vit){this->vit = vit;}int GameRole::getAttack(){return this->atk;}void GameRole::setAttack(int atk){this->atk = atk;}int GameRole::getDefense(){return this->def;}void GameRole::setDefense(int def){this->def = def;}void GameRole::StateDisplay(){cout << "角色当前状态：" << endl;cout << "体力：" << this->vit << endl;cout << "攻击力：" << this->atk << endl;cout << "防御力：" << this->def << endl;  }void GameRole::GetInitState(){this->vit = 100;this->atk = 100;this->def = 100; } void GameRole::Fight(){this->vit = 0;this->atk = 0;this->def = 0; } RoleStateMemento *GameRole::SaveState(){return (new RoleStateMemento(vit, atk, def)); } void GameRole::RecoveryState(RoleStateMemento *memento){this->vit = memento->getVitality();this->atk = memento->getAttack();this->def = memento->getDefense(); } int RoleStateMemento::getVitality(){return this->vit;}void RoleStateMemento::setVitality(int vit){this->vit = vit;}int RoleStateMemento::getAttack(){return this->atk;}void RoleStateMemento::setAttack(int atk){this->atk = atk;}int RoleStateMemento::getDefense(){return this->def;}void RoleStateMemento::setDefense(int def){this->def = def;}RoleStateMemento *RoleStateCaretaker::getMemento(){memento.get();} void RoleStateCaretaker::setMemento(RoleStateMemento *mem){memento.reset(new RoleStateMemento(*mem)); } 

#include "memo.h"int main(){auto_ptr<GameRole> lixiaoyao(new GameRole());lixiaoyao->GetInitState();lixiaoyao->StateDisplay();auto_ptr<RoleStateCaretaker> stateAdmin(new RoleStateCaretaker());stateAdmin->setMemento(lixiaoyao->SaveState());lixiaoyao->Fight();lixiaoyao->StateDisplay();lixiaoyao->RecoveryState(stateAdmin->getMemento()); lixiaoyao->StateDisplay(); return 0; } 

输出结果：

角色当前状态：
体力：100
攻击力：100
防御力：100
In RoleStateMemento's constructor
In RoleStateMemento's copy constructor
角色当前状态：
体力：0
攻击力：0
防御力：0
角色当前状态：
体力：100
攻击力：100
防御力：100