设计模式之c++实现（三）

工厂方法模式

#ifndef __FACTORY_H_
#define __FACTORY_H_

#include "simplefactory.h"

class FactoryBase
{
public:
//声明工厂子类必须实现的接口，不负责产品的创建
virtual CarBase* createCar() = 0;
};
//将实际创建工作推迟到子类
class GMFactory : public FactoryBase
{
public:
CarBase* createCar()
{
return new GMCar();
}
};
class FordFactory : public FactoryBase
{
public:
CarBase* createCar()
{
return new FordCar();
}
};
class ToyotaFactory : public FactoryBase
{
public:
CarBase* createCar()
{
return new ToyotaCar();
}
};
#endif

#include "factory.h"
int main()
{
GMFactory f1;
FordFactory f2;
ToyotaFactory f3;

FactoryBase* pfactory = &f1;
CarBase* pcar = pfactory->createCar();
pcar->printName();
delete pcar;

pfactory = &f2;
pcar = pfactory->createCar();
pcar->printName();
delete pcar;

pfactory = &f3;
pcar = pfactory->createCar();
pcar->printName();
delete pcar;

return 0;
}

class CarFactoryBase
{
public:
template<class Tcar>
static CarBase* createCar()
{
return new Tcar();
}
};

#include "factory.h"
int main()
{
CarBase* pcar = CarFactoryBase::createCar<GMCar>();
pcar->printName();
delete pcar;
pcar = CarFactoryBase::createCar<ToyotaCar>();
pcar->printName();
delete pcar;
pcar = CarFactoryBase::createCar<FordCar>();
pcar->printName();
delete pcar;
return 0;
}