一句话理解
工厂中每个产品自己实现自己的创建函数,工厂只提供函数指针(虚函数)
优点:将工厂和每个产品之间的耦合解决掉,每次增加产品,不需要修改工厂内部代码
例子
#include <iostream>
using namespace std;
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 Factory
{
public:
virtual Product *CreateProduct() = 0;
};
class FactoryA : public Factory
{
public:
Product *CreateProduct()
{
return new ProductA ();
}
};
class FactoryB : public Factory
{
public:
Product *CreateProduct()
{
return new ProductB ();
}
};
int main(int argc , char *argv [])
{
Factory *factoryA = new FactoryA ();
Product *productA = factoryA->CreateProduct();
productA->Show();
Factory *factoryB = new FactoryB ();
Product *productB = factoryB->CreateProduct();
productB->Show();
if (factoryA != NULL)
{
delete factoryA;
factoryA = NULL;
}
if (productA != NULL)
{
delete productA;
productA = NULL;
}
if (factoryB != NULL)
{
delete factoryB;
factoryB = NULL;
}
if (productB != NULL)
{
delete productB;
productB = NULL;
}
return 0;
}