備忘錄模式

前序

相信玩游戲每個人都會，今天就來講講關于游戲進度的保存機制，也就是備忘錄模式。

備忘錄模式

在不破壞封裝性的前提下，捕獲一個對象的內部狀態，兵在該對象之外保存這個狀態。這樣以后就可以將該對象恢復到原先保存的狀態。

實現方式(UML類圖)

實現代碼

#include <stdio.h>

// 角色狀態存信息

class RoleStateMemento

{

public:

         int vit;

         int atk;

         int def;

         int level;

         int pass;

         RoleStateMemento(int _vit, int _atk, int _def, int _level, int _pass) : vit(_vit), atk(_atk), def(_def), level(_level), pass(_pass){}

};

// 游戲角色

class GameRole : public RoleStateMemento

{

public:

         GameRole() : RoleStateMemento(100, 100, 100, 1, 1) {}

         RoleStateMemento* SaveState()

         {

                   return new RoleStateMemento(vit, atk, def, level, pass);

         }

         void RecoveryState(RoleStateMemento* pMemento)

         {

                   vit = pMemento->vit;

                   atk = pMemento->atk;

                   def = pMemento->def;

                   level = pMemento->level;

                   pass = pMemento->pass;

         }

         void Fight()

         {

                   vit -= 20; // 第一關損失了20點血

                   pass++;

                   vit -= 40; // 第二關損失了40點血

                   level++; // 升級了

                   atk++;

                   def++;

                   pass++;

                   vit = 0; // 第三關直接被Boss干掉了

         }

         void StateDisplay()

         {

                   printf("當前血量: %d\n", vit);

                   printf("當前攻擊力: %d\n", atk);

                   printf("當前防御力: %d\n", def);

                   printf("當前等級: %d\n", level);

                   printf("當前關卡: %d\n\n", pass);

         }

};

// 角色狀態管理者

class RoleStateCaretaker

{

public:

         RoleStateMemento* pMemento;

};

int main()

{

         // 大戰Boss前

         GameRole* lixiaoyao = new GameRole();

         // 保存進度

         RoleStateCaretaker* stateAdmin = new RoleStateCaretaker();

         stateAdmin->pMemento = lixiaoyao->SaveState();

         // 大戰Boss時，直接被干掉了

         lixiaoyao->Fight();

         lixiaoyao->StateDisplay();

         // 恢復之前的進度

         if(lixiaoyao->vit == 0)

         {

                   lixiaoyao->RecoveryState(stateAdmin->pMemento);

                   lixiaoyao->StateDisplay();

         }

         delete stateAdmin->pMemento;

         delete stateAdmin;

         delete lixiaoyao;

         return 0;

}

運行結果

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