设计模式之备忘录模式（C++实现）

备忘录模式：

备忘录模式的UML类图：



备忘录模式的实现Demo:

Memento.h
#include <vector>
class Memento;
class GameRole
{
private:
int m_blood;
int m_enery;
public:
GameRole(int blood = 100, int energy = 100);
Memento* Save();
void Load(Memento&);
void Attach();
void Show() const;
};

class Memento
{
public:
int m_blood;
int m_enery;

Memento(int blood=0, int energy=0);

void SetState(const int, const int);

};

class CareTaker
{
private:
std::vector<Memento> vec;
public:
void Save(Memento);
Memento Restore(int index);
};

Memento.cpp
#include"Memento.h"
#include <iostream>
GameRole::GameRole(int blood, int energy) :m_blood(blood), m_enery(energy)
{

}

Memento* GameRole::Save()
{
return new Memento(m_blood, m_enery);
}

void GameRole::Load(Memento& mem)
{
m_blood = mem.m_blood;
m_enery = mem.m_enery;
}

void GameRole::Attach()
{
m_blood -= 10;
m_enery -= 10;
}

void GameRole::Show() const
{
std::cout << m_blood << " " << m_enery << std::endl;
}

Memento::Memento(int blood, int energy)
{
m_blood = blood;
m_enery = energy;
}

void Memento::SetState(int blood, int energy)
{
m_blood = blood;
m_enery = energy;
}

void CareTaker::Save(Memento mem)
{
vec.push_back(mem);
}

Memento CareTaker::Restore(int index)
{
return vec[index];
}

客户端代码：

#include"Memento.h"

int main()
{
CareTaker care;
GameRole role;
role.Show();
care.Save(*(role.Save()));
role.Attach();
role.Show();
care.Restore(0);
role.Load(care.Restore(0));
role.Show();
return 0;
}