C++设计模式之Proxy模式（代理模式）

一时失言乱红尘 2023-03-13 06:14 61阅读 0赞

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 <td> 代理模式很容易理解，就是代替别人去做某一件事，打个比方，我们需要买水果，一般是去超市或者水果店买水果，很少有人去果园买水果，果园是生产水果的地方，但很少出售水果，在这里，水果店，超市就成了代理。 首先定义一个抽象类，提供所有的函数接口。 定义卖水果的抽象类，也就是接口，果园与超市都要继承这个类。 
 <ul style="margin-left:14px;"> 
 <li> #pragma once &nbsp;</li> 
 <li> class CSellFruits//定义一个抽象类 &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> public: &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; CSellFruits(void); &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;virtual&nbsp;~CSellFruits(void); &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; virtual void sellapple()=0;&nbsp;//定义接口，卖苹果 &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; virtual void sellorange()=0;//定义接口，卖橘子 &nbsp;</li> 
 <li> }; &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> #include "SellFruits.h" &nbsp;</li> 
 <li> CSellFruits::CSellFruits(void) &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> } &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> CSellFruits::~CSellFruits(void) &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> } &nbsp;</li> 
 </ul> 2.定义具体类，也就是果园类，果园生产水果，但是一般不买水果 
 <ul style="margin-left:14px;"> 
 <li> #pragma once &nbsp;</li> 
 <li> #include "sellfruits.h" &nbsp;</li> 
 <li> #include &lt;stdio.h&gt; &nbsp;</li> 
 <li> class COrchard : &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;public&nbsp;CSellFruits &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> public: &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; COrchard(void); &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;virtual&nbsp;~COrchard(void); &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; virtual void sellapple(); &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; virtual void sellorange(); &nbsp;</li> 
 <li> }; &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> #include "Orchard.h" &nbsp;</li> 
 <li> COrchard::COrchard(void) &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> } &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> COrchard::~COrchard(void) &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> } &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> void&nbsp;COrchard::sellapple() &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;printf("Sell apple\n"); &nbsp;</li> 
 <li> } &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> void&nbsp;COrchard::sellorange() &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;printf("Sell orange\n"); &nbsp;</li> 
 <li> } &nbsp;</li> 
 </ul>3.定义代理类，代理卖水果的类 
 <ul style="margin-left:14px;"> 
 <li> #pragma once &nbsp;</li> 
 <li> #include "sellfruits.h" &nbsp;</li> 
 <li> #include "Orchard.h" &nbsp;</li> 
 <li> #include &lt;stdio.h&gt; &nbsp;</li> 
 <li> class CProcySellFruits : &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;public&nbsp;CSellFruits &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> public: &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; CProcySellFruits(void); &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;virtual&nbsp;~CProcySellFruits(void); &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; virtual void sellapple(); &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; virtual void sellorange(); &nbsp;</li> 
 <li> private: &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; CSellFruits *p_SellFruits;&nbsp;//传入接口对象 &nbsp;</li> 
 <li> }; &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> #include "ProcySellFruits.h" &nbsp;</li> 
 <li> CProcySellFruits::CProcySellFruits(void):p_SellFruits(NULL) &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> } &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> CProcySellFruits::~CProcySellFruits(void) &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> } &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> void&nbsp;CProcySellFruits::sellapple() &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;if(this-&gt;p_SellFruits==NULL) &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; { &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;this-&gt;p_SellFruits=new&nbsp;COrchard();&nbsp;//用被代理的类实例化 &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; } &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;this-&gt;p_SellFruits-&gt;sellapple();//代理果园卖苹果 &nbsp;</li> 
 <li> } &nbsp;</li> 
 <li> &nbsp;</li> 
 <li> void&nbsp;CProcySellFruits::sellorange() &nbsp;</li> 
 <li> { &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;if(this-&gt;p_SellFruits==NULL) &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; { &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;this-&gt;p_SellFruits=new&nbsp;COrchard();&nbsp;//用被代理的类实例化 &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp; } &nbsp;</li> 
 <li> &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;this-&gt;p_SellFruits-&gt;sellorange();//代理果园卖橘子 &nbsp;</li> 
 <li> } &nbsp;</li> 
 </ul>4.实际调用 
 <ul style="margin-left:14px;"> 
 <li> CProxySellFruits* p=new&nbsp;CProxySellFruits();&nbsp;//用代理类卖水果 &nbsp;</li> 
 <li> p-&gt;SellApple(); &nbsp;</li> 
 <li> p-&gt;SellOrange(); &nbsp;</li> 
 </ul> 版权声明：最终版权归YBAidam所有&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;<a href="https://blog.csdn.net/Aidam_Bo/article/details/81116034" rel="nofollow">https://blog.csdn.net/Aidam_Bo/article/details/81116034</a></td> 
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