装饰器模式

使用场景：动态地给一个对象添加一些额外的职责。

例子：比如手机，有诺基亚手机、苹果手机，允许你为这些手机添加特性，比如增加挂件、屏幕贴膜等。这些挂件和贴膜就是装饰器。

具体实现：

class Phone
{
public:
	Phone() {}
	virtual ~Phone() {}
	virtual void ShowDecorate() {}
};

class iPhone : public Phone
{
private:
	string m_name; //手机名称
public:
	iPhone(string name): m_name(name){}
	~iPhone() {}
	void ShowDecorate() { cout<<m_name<<"的装饰"<<endl;}
};
//具体的手机类
class NokiaPhone : public Phone
{
private:
	string m_name;
public:
	NokiaPhone(string name): m_name(name){}
	~NokiaPhone() {}
	void ShowDecorate() { cout<<m_name<<"的装饰"<<endl;}

　　装饰器类：

class DecoratorPhone : public Phone
{
private:
	Phone *m_phone;  //要装饰的手机
public:
	DecoratorPhone(Phone *phone): m_phone(phone) {}
	virtual void ShowDecorate() { m_phone->ShowDecorate(); }
};
//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<<"增加挂件"<<endl; } //增加的装饰
};
//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; } //增加的装饰
};

　　使用：

int main()
{
	Phone *iphone = new NokiaPhone("6300");
	Phone *dpa = new DecoratorPhoneA(iphone); //装饰，增加挂件
	Phone *dpb = new DecoratorPhoneB(dpa);    //装饰，屏幕贴膜
	dpb->ShowDecorate();
	delete dpa;
	delete dpb;
	delete iphone;
	return 0;
}

　　

 参考：https://blog.csdn.net/wuzhekai1985/article/details/6667564