装饰模式：动态地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为灵活。有时我们希望给某个对象而不是整个类添加一些功能。比如有一个手机，允许你为手机添加特性，比如增加挂件、屏幕贴膜等。一种灵活的设计方式是，将手机嵌入到另一对象中，由这个对象完成特性的添加，我们称这个嵌入的对象为装饰。这个装饰与它所装饰的组件接口一致，因此它对使用该组件的客户透明。
代码如下：

#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
{
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
};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;getchar();return 0;
}

执行结果：