C++设计模式之简单工厂模式实例

2.由于对象的创建过程是我们不需要去关心的，而我们注重的是对象的实际操作，所以，我们需要分离对象的创建和操作两部分，如此，方便后期的程序扩展和维护。

代码实现：
/*
** FileName   : SimpleFactoryPatternDemo
** Author    : Jelly Young
** Date     : 2013/11/17
** Description : More information
*/
 
#include <iostream>
#include <vector>
using namespace std;
 
typedef enum ProductTypeTag
{
  TypeA,
  TypeB,
  TypeC
}PRODUCTTYPE;
 
// Here is the product class
class Product
{
public:
  virtual void Show() = 0;
};
 
class ProductA : public Product
{
public:
  void Show()
  {
    cout<<"I'm ProductA"<<endl;
  }
};
 
class ProductB : public Product
{
public:
  void Show()
  {
    cout<<"I'm ProductB"<<endl;
  }
};
 
class ProductC : public Product
{
public:
  void Show()
  {
    cout<<"I'm ProductC"<<endl;
  }
};
 
// Here is the Factory class
class Factory
{
public:
  Product* CreateProduct(PRODUCTTYPE type)
  {
    switch (type)
    {
    case TypeA:
      return new ProductA();
 
    case TypeB:
      return new ProductB();
 
    case TypeC:
      return new ProductC();
 
    default:
      return NULL;
    }
  }
};
 
int main(int argc, char *argv[])
{
  // First, create a factory object
  Factory *ProductFactory = new Factory();
  Product *productObjA = ProductFactory->CreateProduct(TypeA);
  if (productObjA != NULL)
    productObjA->Show();
 
  Product *productObjB = ProductFactory->CreateProduct(TypeB);
  if (productObjB != NULL)
    productObjB->Show();
 
  Product *productObjC = ProductFactory->CreateProduct(TypeC);
  if (productObjC != NULL)
    productObjC->Show();