《设计模式》学习笔记——装饰模式

装饰模式(Decorator Pattern)指的是在不必改变原类文件和使用继承的情况下，动态地扩展一个对象的功能.它是通过创建一个包装对象，也就是装饰来包裹真实的对象。

DecoratorPattern.h

#pragma once
#include
#include


class Car
{
public:
	virtual void show(void) = 0;
};

class RunCar:public Car
{
public:
	virtual void show(void) { std::cout << "可以跑" << std::endl; }
private:
protected:

};

// 装饰类
class SwimCarDecorator:public Car
{
public:
	SwimCarDecorator(Car* car):m_car(car) {}
	~SwimCarDecorator() {delete m_car;}

	
	virtual void show(void)
	{ 
		// 执行原有功能
		m_car->show();
		// 执行装饰功能
		swim();
	}
private:
	Car * m_car;

	void swim(void) { std::cout << "会游泳" << std::endl; }
protected:

};

// 装饰类
class FlayCarDecorator :public Car
{
public:
	FlayCarDecorator(Car* car) :m_car(car) {}
	~FlayCarDecorator() { delete m_car; }


	virtual void show(void)
	{
		// 执行原有功能
		m_car->show();
		// 执行装饰功能
		flay();
	}
private:
	Car * m_car;

	void flay(void) { std::cout << "能够飞" << std::endl; }
protected:

};

class DecoratorPattern
{
public:
	DecoratorPattern() {};
	~DecoratorPattern() {};
};

 

DecoratorPattern.cpp

#include "DecoratorPattern.h"

 

mainTest.cpp

#include
#include"DecoratorPattern.h"

int main(void)
{
	Car* car = nullptr;
	car = new RunCar;
	car->show();

	FlayCarDecorator* flayCar = new FlayCarDecorator(car);
	flayCar->show();

	SwimCarDecorator* swimCar = new SwimCarDecorator(flayCar);
	swimCar->show();

	delete swimCar;
	delete flayCar;
	delete car;


	system("pause");
	return 0;
}