C++（简单工厂）

// ConsoleApplication18.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

typedef enum Type
{
    TypeA,
    TypeB,
    TypeC,
} ProductType;

class Product
{
public:
    void virtual Show()=0;

};

class ProductA:public Product
{
public:
    void Show()
    {
        cout<<"ShowA"<<endl;
    }
};

class ProductB:public Product
{
public:
    void Show()
    {
        cout<<"ShowB"<<endl;
    }
};

class ProductC:public Product
{
public:
    void Show()
    {
        cout<<"ShowC"<<endl;
    }
};

class SimpleFactory
{
public:
    Product* CreatInstance(ProductType pt)
    {
        switch(pt)
        {
        case TypeA:
            return new ProductA();
            break;
        case TypeB:
            return new ProductB();
            break;
        case TypeC:
            return new ProductC();
            break;
        default:
            return NULL;
            break;
        }
    }
};

int _tmain(int argc, _TCHAR* argv[])
{
    SimpleFactory *sf = new SimpleFactory();
    Product *pa = sf->CreatInstance(TypeA);
    pa->Show();

    Product *pb = sf->CreatInstance(TypeB);
    pb->Show();

    Product *pc = sf->CreatInstance(TypeC);
    pc->Show();

    delete pa,pb,pc;
    return 0;
}