C++大学基础教程_10_10_代理类

//Implementation.h
//包含欲隐藏的私有实现的类生成类定义
class Implementation
{
public:
	Implementation(int v)
		:value(v)
	{
		//空函数体
	}
    void setValue(int v)
	{
		value = v;
	}
	int getValue()
	{
		return value;
	}

private:
	int value;
};

//Interface.h
//代理类Interface

class Implementation;//声明
class Interface
{
public:
	Interface(int);
	~Interface();
	void setValue(int);
	int getValue() const;
private:
	Implementation *iPtr;
};

//Interface.cpp
#include "Interface.h"
#include "Implementation.h"

Interface::Interface(int v)
	:iPtr(new Implementation(v))
{
	// empty body
}

Interface::~Interface()
{
	delete iPtr;
	iPtr = 0;
}

void Interface::setValue(int v)
{
	iPtr->setValue(v);
}

int Interface::getValue() const
{
	return iPtr->getValue();
}

//main.cpp

//#include "Implementation.h"
#include "Interface.h"//只有这一个头文件包含在代码中，！！！
#include <iostream>
using namespace std;

int main()
{
	Interface testInt(6);
	cout << "Interface contains: " << testInt.getValue() 
		   << " before setValue." << endl;
	testInt.setValue(7);
	cout << "Interface contains:" << testInt.getValue()
		   << " after setValue." << endl;
	system("pause >> cout");
	return 0;
}