迭代器模式【ITERATOR PATTERN 】

 iterator.h

/*
 * iterator.h
 *
 *  Created on: Sep 29, 2012
 *      Author: hl
 */

#ifndef _ITERATOR_H_
#define _ITERATOR_H_
#include <string>
#include <vector>
using namespace std;

/**
 * @brief 迭代器模式
 */
class IProject
{
public:
    virtual void show() = 0;
};

class Project : public IProject
{
public:
    Project(string proName, double money, string time);
public:
    void show();
private:
    string _proName;
    double _money;
    string _time;
};

class ProIterator;

/**
 * @brief 项目管理器
 */
class ProManager
{
public:
    ProManager();
    ~ProManager();
public:
    void proAdd(string proName, double money, string time);
    ProIterator * getIterator();            /// < 得到对象的遍历器
private:
    vector<Project * >  * vec;
};

/**
 * @brief 项目遍历器
 */
class ProIterator
{
public:
    ProIterator(vector<Project * > *vec);
    ~ProIterator();
public:
    bool hasNext();            /// < 是否有下一个！
    Project * next();        /// <
    void erase();            /// < 遍历一个，释放一个，并且重新组织新的遍历器！
private:
    vector<Project * > * _vec;
    vector<Project * >::iterator iter;
};

#endif /* _ITERATOR_H_ */

iterator.cpp

//============================================================================
// Name        : iterator.cpp
// Author      : hl
// Version     :
// Copyright   : Copyright (c) 2012 Tiros
// Description : Iterator Pattern in C++, Ansi-style
//============================================================================

#include "iterator.h"
#include <iostream>
using namespace std;


Project::Project(string proName, double money, string time)
{
    this->_proName = proName;
    this->_money = money;
    this->_time = time;
}

void Project::show()
{
    cout << "项目名称: " << this->_proName << " 项目资金: "
            << this->_money << " 项目启动时间: " << this->_time;
}

ProManager::ProManager()
{
    this->vec = new vector<Project * >;
    if (!this->vec)
        return ;
}

ProManager::~ProManager()
{
    //TODO
}

void ProManager::proAdd(string proName, double money, string time)
{
    Project * pro = new Project(proName, money, time);
    this->vec->push_back(pro);
}

ProIterator * ProManager::getIterator()
{
    return (new ProIterator(this->vec));
}

ProIterator::ProIterator(vector<Project * > *vec)
{
    if (!vec)
        return ;
    this->_vec = vec;
    this->iter = this->_vec->begin();
}

ProIterator::~ProIterator()
{
    //TODO
}

bool ProIterator::hasNext()
{
    if (0 == this->_vec->size())
        return false;
    return true;
}

Project * ProIterator::next()
{
    if ( 0 == this->_vec->size())
        return NULL;
    return *(this->iter);
}

void ProIterator::erase()
{
    this->_vec->erase(this->iter);
    this->iter  = this->_vec->begin();    /// < 释放之后重新调整迭代器
}

string getTimeStr()
{
    time_t timep;

    time(&timep); /*获取time_t类型的当前时间*/
    /*用gmtime将time_t类型的时间转换为struct tm类型的时间按，／／没有经过时区转换的UTC时间
     然后再用asctime转换为我们常见的格式 Fri Jan 11 17:25:24 2012
      1> asctime(gmtime(&timep))
      2> ctime(&timep) //经过时区转换的
     */
    return ctime(&timep);
}

int main()
{
    ProManager pro;
    pro.proAdd("计划书", 300000.00, getTimeStr());
    pro.proAdd("分布式", 400000.00, getTimeStr());
    pro.proAdd("ERP", 600000.00, getTimeStr());

    ProIterator * pProIterator = pro.getIterator();
    while (pProIterator->hasNext())
    {
        Project * tp = pProIterator->next();
        tp->show();
        pProIterator->erase();
    }
    delete pProIterator;

    return 0;
}