设计模式-装饰器模式

• 装饰器模式
• • 为什么又装饰器模式？
  • 装饰器模式

给类增加功能,他与代理模式的设计结构非常相似

class Car // 抽象基类
{
public:
	virtual void show() = 0;
};

//三个实体的汽车类
class Bmw : public Car
{
public:
	void show() 
	{
		cout << "这是一辆宝马汽车，配置有：基类配置";
	}
};
class Audi : public Car
{
public:
	void show()
	{
		cout << "这是一辆奥迪汽车，配置有：基类配置";
	}
};
class Benz : public Car
{
public:
	void show()
	{
		cout << "这是一辆奔驰汽车，配置有：基类配置";
	}
};

//装饰器的基类
// 装饰器1  定速巡航
class ConcreteDecorator01 : public Car
{
public:
	ConcreteDecorator01(Car *p) :pCar(p) {}
	void show()
	{
		pCar->show();
		cout << ",定速巡航";
	}
private:
	Car *pCar;
};
class ConcreteDecorator02 : public Car
{
public:
	ConcreteDecorator02(Car *p) :pCar(p) {}
	void show()
	{
		pCar->show();
		cout << ",自动刹车";
	}
private:
	Car *pCar;
};
class ConcreteDecorator03 : public Car
{
public:
	ConcreteDecorator03(Car *p) :pCar(p) {}
	void show()
	{
		pCar->show();
		cout << ",车道偏离";
	}
private:
	Car *pCar;
};

int main()
{
	Car *p1 = new ConcreteDecorator01(new Bmw());
	p1 = new ConcreteDecorator02(p1);
	p1 = new ConcreteDecorator03(p1);
	p1->show();
	cout << endl;

	Car *p2 = new ConcreteDecorator02(new Audi());
	p2->show();
	cout << endl;

	Car *p3 = new ConcreteDecorator03(new Benz());
	p3->show();
	cout << endl;

	return 0;
}