自己写的方便文件输入输出的模板类

有个朋友问了我一些关于文件读写的问题。其实我比较恨文件读写，我在文件读写上经常出现一些问题。所以这次狠下心决定写一个通用模板类，处理一些常见的问题。代码如下

 

template <class T>
class CFileOperation
{
private:
    vector<T>    m_vecElements;

public:
    CFileOperation();
    ~CFileOperation();
    /*第二个参数是一个函数指针，用来作为处理每一个已读字符串，可以通过该函数将字符串转换成需要的类型T,或者进行一些其他的处理。第四个参数是选择需要保留之前已经读取的数据。*/
    bool ReadFromFile(char * filename, \
        T (*dealElement)(char * , void *), void * param = NULL,\
        bool bErase = false);
    /*第二个参数是间隔，用于间隔两个数据。第三个参数是一个函数指针，用来作为处理每一个需要写进文件的T类型数据，可以通过该函数加工T类型数据。*/
    bool WriteIntoFile(char * filename, vector<T> & arrayOut, char * interval,\
        T (*dealElement)(T& , void *) = NULL , void * param = NULL);
    bool GetElement(int index, T * result);
    vector<T> GetWholeVector();
};



template <class T>
vector<T> CFileOperation<T>::GetWholeVector()
{
    return m_vecElements;
}


template <class T>
bool CFileOperation<T>::GetElement(int index, T * pResult)
{
    if (m_vecElements.size() == 0 || index >= m_vecElements.size())
    {
        cerr << "the size you entered is longer than the vector\n";
        pResult = NULL;
        return false;
    }
    *pResult = m_vecElements[index];
    return true;
}

template <class T>
bool CFileOperation<T>::WriteIntoFile(char * filename, vector<T> & arrayOut,char * interval,T (*dealElement)(T & , void *),void * param)
{
    if (filename == NULL)
    {
        return false;
    }
    ofstream outfile(filename, ios_base::trunc);

    if (!outfile)
    {
        cerr << "error in open the file";
        return false;
    }

    int i = 0;
    while(i < arrayOut.size())
    {
        T t = arrayOut[i];
        if (dealElement != NULL)
        {
            t = dealElement(arrayOut[i], param);
        }
        outfile << t;
        outfile << interval;
        i++;
    }

    outfile.close();
    return true;
}


template <class T>
bool CFileOperation<T>::ReadFromFile(char * filename, T (*dealElement)(char * , void *) ,
    void * param,
    bool bErase)
{
    //将先前的内容清楚
    if (filename == NULL)
    {
        return false;
    }

    ifstream infile(filename);
    if (infile.fail())
    {
        cerr << "error in open the file";
        return false;
    }

    if (bErase)
    {
        m_vecElements.clear();
    }

    while(1)
    {
        char temp[100];
        infile >> temp;

        T t = dealElement(temp, param);
        
        m_vecElements.push_back(t);

        if (infile.eof())
        {
            break;
        }
    }
    infile.close();
    return true;
}




template <class T>
CFileOperation<T>::~CFileOperation()
{
}

template <class T>
CFileOperation<T>::CFileOperation()
{
}

 

 

 测试使用的代码

 

#include "stdafx.h"

#include <stdlib.h>

#include <iostream>

#include <vector>

#include "FileOperation.h"



using namespace std;







double DealDouble(char * charactor, void * param)

{

    return  ( atof(charactor) + 1);

}



string DealString(char * charactor, void * param)

{

    string str(charactor);

    return str.append("111111");

}



string BeforWriting(string & charactor, void * param)

{

    return charactor.append("111111");

}



int _tmain(int argc, _TCHAR* argv[])

{

    CFileOperation<double> fileOperation;



    fileOperation.ReadFromFile("d:\\1.txt", DealDouble, NULL, false);

    

    vector<double> vec = fileOperation.GetWholeVector();



    for (int i = 0;i < vec.size();i++)

    {

        cout << vec[i] << endl;

    }



    double d;

    if( fileOperation.GetElement(3, &d) )

        cout << "the third element is : " << d << endl;



    //append some some other number and then to write into files

    for (int i = 0; i < 5; i++)

    {

        vec.push_back(i + 50.512345);

    }



    fileOperation.WriteIntoFile("d:\\3.txt", vec, "\n");





    //////////////////////////////////////////////////////

    CFileOperation<string> fileOperation2;



    fileOperation2.ReadFromFile("d:\\2.txt", DealString, NULL, false);



    vector<string> vec2 = fileOperation2.GetWholeVector();



    for (int i = 0;i < vec2.size();i++)

    {

        cout << vec2[i] << endl;

    }



    string d2;

    if( fileOperation2.GetElement(3, &d2) )

        cout << "the third element is : " << d2 << endl;



    //append some some other number and then to write into files

    for (int i = 0; i < 5; i++)

    {

        string str("456231456");

        vec2.push_back(str);

    }



    fileOperation2.WriteIntoFile("d:\\4.txt", vec2, "\n", BeforWriting);



    return 0;

}