2、手机备份软件的设计与实现

1.不使用外观模式的实现方式

TelphoneNumber为通讯录备份模块、ShortMessage为短信备份模块、Image为照片备份模块。实现代码如下:

#ifndef _RESOURSE_H_
#define _RESOURSE_H_

#include 
  
   
#include 
   
     using namespace std; //电话号码类 class TelphoneNumber { public: void BakeUpTelphoneNumber() { cout << "备份电话号码" << endl; } }; //短信类 class ShortMessage { public: void BakeUpShortMessage() { cout << "备份短信" << endl; } }; //照片类 class Image { public: void BakeUpImage() { cout << "备份照片" << endl; } }; #endif
   
  

#include 
  
   
#include "Resourse.h"
using namespace std;

int main()
{
	/*******************备份电话号码**************************/
	TelphoneNumber * pTelphoneNumber  = new TelphoneNumber();
	pTelphoneNumber->BakeUpTelphoneNumber();

	/*******************备份短信**************************/
	ShortMessage * pShortMessage = new ShortMessage();
	pShortMessage->BakeUpShortMessage();

	/*******************备份照片**************************/
	Image * pImage = new Image();
	pImage->BakeUpImage();

	/*******************销毁操作**************************/
	delete pTelphoneNumber;
	pTelphoneNumber = NULL;
	delete pShortMessage;
	pShortMessage = NULL;
	delete pImage;
	pImage = NULL;

	return 0;
}
  

虽然上述代码能实现对电话号码，短信，照片进行备份。但客户端直接操作电话备份、短信备份、照片备份模块，客户端需要知道备份的具体细节，客户端与这三个类耦合性升高了，违背迪迷特法则，最小朋友原则。现在只在客户端进行备份操作，如果其他地方也需要备份操作，复用性不强；如果备份操作进行了修改，则多个地方将进行修改，维护性差。因此需要对上述代码进行重构，封装一个外观类，由外观类对三种资源进行备份操作，使得客户类与备份模块解耦。

2.使用外观模式的实现方式<??http://www.2cto.com/kf/ware/vc/" target="_blank" class="keylink">vcD4KPHA+ICAgILG4t93Eo7/ptPrC68O709Cx5Luvo6zKtc/WtPrC68jnz8I6PC9wPgo8cHJlIGNsYXNzPQ=="brush:java;">#ifndef _RESOURSE_H_ #define _RESOURSE_H_ #include #include using namespace std; //电话号码类 class TelphoneNumber { public: void BakeUpTelphoneNumber() { cout << "备份电话号码" << endl; } }; //短信类 class ShortMessage { public: void BakeUpShortMessage() { cout << "备份短信" << endl; } }; //照片类 class Image { public: void BakeUpImage() { cout << "备份照片" << endl; } }; #endif 添加一个备份外观类BakeupFacade，由它对备份模块进行操作，解除客户类与具体备份模块的耦合。它将所有从客户端发来的请求委派到相应的子 系统去，传递给相应的子系统对象处理。

#ifndef _FACADE_H_
#define _FACADE_H_

#include "Resourse.h"


//备份外观
class BakeupFacade
{
private:
	//维护对电话号码、短信、照片对象的引用
	TelphoneNumber * m_pTelphoneNumber;
	ShortMessage * m_pShortMessage;
	Image * m_pImage;
public:
	//外观构造函数，创建手机，短信，照片对象
	BakeupFacade()
	{
		m_pTelphoneNumber = new TelphoneNumber();
		m_pShortMessage = new ShortMessage();
		m_pImage = new Image();
	}

	//备份资源
	void BakeupResourse()
	{
		m_pTelphoneNumber->BakeUpTelphoneNumber();
		m_pShortMessage->BakeUpShortMessage();
		m_pImage->BakeUpImage();
	}
};


#endif

#include 
  
   
#include "Facade.h"
using namespace std;


int main()
{
	//创建外观对象
	BakeupFacade * pBakeupFacade = new BakeupFacade();

	//备份
	pBakeupFacade->BakeupResourse();

	//销毁对象
	delete pBakeupFacade;
	pBakeupFacade = NULL;

	return 0;
}
  

编译并执行，结果如下: