C++ Factory 方法

Singleton.h

#pragma once#ifndef SINGLETON_H#define SINGLETON_Htemplate<class T>class Singleton{public:static T& Instance();protected:Singleton(){}virtual ~Singleton(){}/** * 防止拷貝複製 */private:Singleton(const Singleton &);Singleton & operator = (const Singleton &);};template<class T>T& Singleton<T>::Instance(){/** 建立一個靜態對象 */static T instance;return instance;}#endif

ObjectFactory.h

/**--------------------------------* 對象原廠模式(Object Factory)** Code by XadillaX* http://www.xcoder.in* Created at 2010-11-17 1:33*/ #ifndef OBJECTFACTORY_H #define OBJECTFACTORY_H #pragma once #include <map> #include <string> #include "Singleton.h" template<class T> class ObjectFactory : public Singleton<ObjectFactory<T>> { public: typedef T* (*tCreator)(); ///< 重定義對象產生函數指標 typedef std::map<std::string, tCreator> tCreatorMap; ///< 對象產生函數指標map /*** @brief 註冊新"生產車間"* 將產生對象的函數加入對象工廠** @param *name 類名稱* @param procedure "生產"對象的函數* @return 是否成功註冊*/ bool Register(char *type, tCreator procedure); /*** @brief 找到"生產車間"* 根據傳入的類名返回相應的新對象的產生函數** @param &type 類名* @return 相應的新對象的產生函數*/ T* Create(const std::string &type); private: /** "生產車間"映射 */ tCreatorMap _map; }; template<class T> bool ObjectFactory<T>::Register(char *type, tCreator procedure) { string tmp(type); /** 將新函數加入map中 */ _map[tmp] = procedure; return _map[tmp]; } template<class T> T* ObjectFactory<T>::Create(const std::string &type) { /** 在映射中找到相應"生產車間" */ tCreatorMap::iterator iter = _map.find(type); /** 檢測"車間"是否存在 */ if(iter != _map.end()) { /** 讓傳回值為相應的"生產車間" */ tCreator r = iter->second; /** 返回"生產車間" */ return r(); } return 0; } #endif 

Main.cpp

 #include <iostream> #include "ObjectFactory.h" using namespace std; /** 基類 */ class Base; /** Base類及其子類的對象工廠 */ typedef ObjectFactory<Base> BaseFactory; class Base { public: Base(){}; ~Base(){}; }; class A : public Base { public: A(){ cout << "A object created." << endl; }; ~A(){}; static Base* ACreator() { return new A(); };}; class B : public Base { public: B(){ cout << "B object Created." << endl; } ~B(); static Base* BCreator() { return new B(); } }; /*** @brief 主函數*/ int main() { /** 將A、B的"生產車間"註冊到對象工廠中 */ bool AFlag = BaseFactory::Instance().Register("A", A::ACreator);bool BFlag = BaseFactory::Instance().Register("B", B::BCreator); /** 若註冊失敗則退出 */ if(!AFlag || !BFlag) exit(0); Base *p; for(int i = 0; i < 10; i++) { string type = (i % 2) ? string("A") : string("B"); /** p用相應"生產車間"進行生產 */ p = BaseFactory::Instance().Create(type); delete p; } return 0; }