3 装饰模式（1）

#include <iostream>
#include <string>

 using std::string;
 using std::cout;
 using std::endl;

class Component
{
public:
    virtual void Operation() = 0;
};

class ConcreteComponent : public Component
{
public:
    void Operation()
    {
        cout<<"具体对象的操作"<<endl;
    }
};

//装饰抽象类
class Decorator : public Component
{
public:
    void SetComponent(Component* component)
    {
        this->component = component;
    }
    void Operation()
    {
        component->Operation();
    }
private:
    Component* component;
};

//具体装饰类A
class ConcretorDecoratorA : public Decorator
{
public:
    void Operation()
    {
        Decorator::Operation();
        addedState = "new state";
        cout<<"具体对象A的操作"<<endl;

    }
private:
        string addedState;
};

//具体装饰类B
class ConcretorDecoratorB : public Decorator
{
public:
    void Operation()
    {
        Decorator::Operation();
        AddedBehavior();
        cout<<"具体对象B的操作"<<endl;
    }
    void AddedBehavior()
    {
        cout<<"具体装饰类B新增加的功能"<<endl;
    }
};

int main()
{
    //客户端实现
    ConcreteComponent* c = new ConcreteComponent();
    ConcretorDecoratorA *pa = new ConcretorDecoratorA();
    ConcretorDecoratorB *pb = new ConcretorDecoratorB();

    pa->SetComponent(c);
    pb->SetComponent(pa);
    pb->Operation();
    return 0;
}