备忘录模式

#include <stdio.h>
#include <iostream>
using namespace std;

class RoleStateMemento;

class GameRole {
private :
    int vit;
    int attack;
    int def;
    
public:
    void setVitality(int vitality){vit = vitality;}
    void setDefence(int defence){def = defence;}
    void setAttack(int attack) {this->attack = attack;}
    
    int getVitality(){return vit;}
    int getDefence(){return def;}
    int getAttack(){return attack;}
    
    void StateDisplay(){
        cout<<"current state:"<<endl;
        cout<<"vitality"<<vit<<endl;
        cout<<"attack"<<attack<<endl;
        cout<<"defence"<<def<<endl;
    }
    
    RoleStateMemento * SaveState();
    void RecoveryState(RoleStateMemento * memento);
    
    void GetInitState(){
        vit = 100;
        attack = 100;
        def = 100;
    }
    void Fight(){
        vit = 0;
        attack = 0;
        def = 0;

    }
};

class RoleStateMemento {
    
private :
    int vit;
    int attack;
    int def;
    
public:
    RoleStateMemento(int vit,int attack ,int def):vit(vit),attack(attack),def(def){}
    int getVitality(){return vit;}
    int getDefence(){return def;}
    int getAttack(){return attack;}
};

class RoleStateCaretaker {
private:
    RoleStateMemento * memento;
public:
    void setMemento (RoleStateMemento * memento){this->memento = memento;}
    RoleStateMemento * getMemento(){return memento;}
};

//.m

RoleStateMemento * GameRole::SaveState() {
    return new RoleStateMemento(vit,attack,def);
}

void GameRole::RecoveryState(RoleStateMemento *memento) {
    this->vit = memento->getVitality();
    this->attack = memento->getAttack();
    this->def = memento->getDefence();
}

void testLesson14(){
    GameRole * lixiaoyao = new GameRole();
    lixiaoyao->GetInitState();
    lixiaoyao->StateDisplay();
    
    RoleStateCaretaker * stateAdmin = new RoleStateCaretaker();
    stateAdmin->setMemento(lixiaoyao->SaveState());
    
    lixiaoyao->Fight();
    lixiaoyao->StateDisplay();
    
    lixiaoyao->RecoveryState(stateAdmin->getMemento());
    lixiaoyao->StateDisplay();
    

}

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种状态，这样以后就可将该对象恢复到原先保存的状态。
缺点：角色状态需要完整存贮到备忘录对象中，如果数据很大很多，就会在资源的消耗上比较大。