factory

factory 模式
功能：
1)  定义创建对象的接口，封装了对象的创建
2)  使得具体化类的工作延迟到了子类中

//product.h
#ifndef _PRODUCT_H
#define _PRODUCT_H
class Product
{
   public:
      virtual ~ Product() = 0;
   protected:
      Product();
};

class ConcreteProduct : public Product
{
    public:
      ~ConcreteProduct();
      ConcreteProduct();
};
#endif

------------------------------------------
//Product.cpp
#include

#include "Product.h"

using namespace std;

Product::Product()
{
}
Product::~Product()
{
}

ConcreteProduct::ConcreteProduct()
{
    cout << "ConcreteProduct..." << endl;
}

ConcreteProduct::~ConcreteProduct()
{
}

------------------------------------
//Factory.h
#ifndef  _FACTORY_H
#define  _FACTORY_H
class Product;

class Factory
{
   public:
     virtual ~Factory() = 0;
     virtual Product * CreateProduct() = 0;
   protected:
     Factory();
};

class ConcreteFactory:public Factory
{
   public:
     ~ConcreteFactory();
     ConcreteFactory();
     Product * CreateProduct();
};
#endif

---------------------------------
//Factory.cpp
#include "Factory.h"
#include "Product.h"

#include
using namespace std;

Factory::Factory()
{
}

Factory::~Factory()
{
}

ConcreteFactory::ConcreteFactory()
{
    cout << "ConcreteFactory..." << endl;
}

ConcreteFactory::~ConcreteFactory()
{
}

Product * ConcreteFactory::CreateProduct()
{
    return new ConcreteProduct();
}


=================================================
//main.cpp
#include "Factory.h"
#include "Product.h"

#include
using namespace std;

int main(int argc, char * argv[])
{
   Factory * fac = new ConcreteFactory();
   Product * p = fac->CreateProduct();

   return 0;
}