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<iostream>
#include<string>
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<iostream>
#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;
}