代理模式

前序

卓賈易同學(xué)為了追求嬌嬌同學(xué),于是要戴勵(lì)同學(xué)幫他送洋娃娃,花和巧克力給嬌嬌同學(xué).請(qǐng)你用代理模式來(lái)設(shè)計(jì)這些送東西的過程.

代理模式

代理模式給某一個(gè)對(duì)象提供一個(gè)代理對(duì)象，并由代理對(duì)象控制對(duì)源對(duì)象的引用。代理就是一個(gè)人或一個(gè)機(jī)構(gòu)代表另一個(gè)人或者一個(gè)機(jī)構(gòu)采取行動(dòng)。某些情況下，客戶不想或者不能夠直接引用一個(gè)對(duì)象，代理對(duì)象可以在客戶和目標(biāo)對(duì)象直接起到中介的作用。客戶端分辨不出代理主題對(duì)象與真實(shí)主題對(duì)象。代理模式可以并不知道真正的被代理對(duì)象，而僅僅持有一個(gè)被代理對(duì)象的接口，這時(shí)候代理對(duì)象不能夠創(chuàng)建被代理對(duì)象，被代理對(duì)象必須有系統(tǒng)的其他角色代為創(chuàng)建并傳入。

實(shí)現(xiàn)方式(UML類圖)

實(shí)現(xiàn)代碼

#include <stdio.h>

class IGiveGift

{

public:

       virtual void GiveDolls()=0;

       virtual void GiveFlowers()=0;

       virtual void GiveChocolate()=0;

};

class SchoolGirl

{

public:

       char*& Name()

       {

              return name;

       }

protected:

       char* name;

};

class Pursuit : public IGiveGift

{

public:

       Pursuit(SchoolGirl* _mm) : mm(_mm){}

       virtual void GiveDolls()

       {

              printf("%s 送你洋娃娃\n",mm->Name());

       }

       virtual void GiveFlowers()

       {

              printf("%s 送你鮮花\n",mm->Name());

       }

       virtual void GiveChocolate()

       {

              printf("%s 送你巧克力\n",mm->Name());

       }

protected:

       SchoolGirl* mm;

};

class Proxy : public IGiveGift

{

public:

       Proxy(SchoolGirl* mm)

       {

              gg = new Pursuit(mm);

       }

       ~Proxy()

       {

              delete gg;

       }

       virtual void GiveDolls()

       {

              gg->GiveDolls();

       }

       virtual void GiveFlowers()

       {

              gg->GiveFlowers();

       }

       virtual void GiveChocolate()

       {

              gg->GiveChocolate();

       }

protected:

       Pursuit* gg;

};

int main()

{

       SchoolGirl* jiaojiao = new SchoolGirl();

       jiaojiao->Name() = "李嬌嬌";

       Proxy* daili = new Proxy(jiaojiao);

       daili->GiveDolls();

       daili->GiveFlowers();

       daili->GiveChocolate();

       delete jiaojiao;

       delete daili;

       return 0;

}

運(yùn)行結(jié)果