（转）设计模式--装饰器模式

动态的给一个对象添加一些额外的职责，就增加功能来说，装饰模式相比生成子类更灵活。装饰器模式，顾名思义，就是对已经存在的某些类进行装饰，以此来扩展一些功能。

职责：动态的为一个对象增加新的功能

#include <iostream>
#include <string>

using namespace std;

//公共抽象类
class Phone
{
public:
	Phone(){}
	virtual ~Phone(){}
	virtual void ShowDecorate(){}
};
//具体的手机类
class iPhone :public Phone
{
public:
	iPhone(string name) :m_name(name){}
	~iPhone(){}
	void ShowDecorate()
	{
		cout << m_name << "的装饰" << endl;
	}
private:
	string m_name;
};
//具体的手机类
class NokiaPhone :public Phone
{
public:
	NokiaPhone(string name) :m_name(name){}
	~NokiaPhone(){}
	void ShowDecorate()
	{
		cout << m_name << "的装饰" << endl;
	}
private:
	string m_name;
};
//装饰类
class DecoratorPhone :public Phone
{
public:
	DecoratorPhone(Phone *phone) :m_phone(phone){}
	~DecoratorPhone(){ delete m_phone; }
	virtual void ShowDecorate(){ m_phone->ShowDecorate(); }
private:
	Phone *m_phone;		//要装饰的手机
};
//具体的装饰类
class DecoratorPhoneA :public DecoratorPhone
{
public:
	DecoratorPhoneA(Phone *phone) :DecoratorPhone(phone){}
	void ShowDecorate(){ DecoratorPhone::ShowDecorate(); AddDecorate(); }
private:
	void AddDecorate(){ cout << "挂件功能" << endl; }
};
//具体的装饰类
class DecoratorPhoneB :public DecoratorPhone
{
public:
	DecoratorPhoneB(Phone *phone) :DecoratorPhone(phone){}
	void ShowDecorate(){ DecoratorPhone::ShowDecorate(); AddDecorate(); }
private:
	void AddDecorate(){ cout << "屏幕贴膜" << endl; }
};

int main()
{
	Phone *iphone = new iPhone("6300");
	Phone *dpa = new DecoratorPhoneA(iphone);
	Phone *dpb = new DecoratorPhoneB(dpa);
	dpb->ShowDecorate();
	system("Pause");
	return 0;
}

#include <iostream>
#include<string>

using namespace std;
//定义一个原始的抽象蛋糕
class Cake
{
public:
	virtual void showCake() = 0;
	virtual ~Cake(){}
public:
	string name;
};
//构建原始蛋糕
class ConcreteCake :public Cake
{
public:
	ConcreteCake()
	{
		name = "原始蛋糕";
	}
	void showCake(){ cout << name << endl; }
	virtual ~ConcreteCake(){}
};
//定义装饰器类，装饰器类继承被装饰类，抽象类作为接口
class CakeDecrator :public Cake
{
public:
	virtual void showCake() = 0;
	virtual ~CakeDecrator(){}
protected:
	Cake *pCake;
};
//定义具体的修饰器
class CakeDecratorMile :public CakeDecrator
{
public:
	CakeDecratorMile(Cake *pCake)
	{
		this->pCake = pCake;
	}
	void showCake()
	{
		this->name = pCake->name + "加奶油";
		cout << this->name << endl;
	}
	virtual ~CakeDecratorMile(){};
};
//定义具体修饰器
class CakeDecratorCholate :public CakeDecrator
{
public:
	CakeDecratorCholate(Cake *pCake)
	{
		this->pCake = pCake;
	}
	void showCake()
	{
		this->name = pCake->name + "加巧克力";
		cout << this->name << endl;
	}
	virtual ~CakeDecratorCholate(){};
};

int main()
{
	ConcreteCake *pConCake = new ConcreteCake();
	pConCake->showCake();

	CakeDecratorMile *pDecMile = new CakeDecratorMile(pConCake);
	pDecMile->showCake();
	CakeDecratorCholate *pDecCho = new CakeDecratorCholate(pDecMile);
	pDecCho->showCake();

	delete pConCake;
	delete pDecMile;
	delete pDecCho;

	system("Pause");
	return 0;
}