1 通过关键词，读取某一行（3种方法）

通过定位关键词，读取某一行信息,返回CString

//通过定位关键词，读取某一行信息，返回CString
CString fileRW::Read_CStrLine(CString KEY)
{ifstream ifs; //创建文件输入对象ifs.open("../x64/Debug/config.ini", ios::in); //打开文件if (!ifs.is_open()) {cout << "文件打开失败" << endl;return _T("");}CString StrLine;//读文件，读取关键词KEY的下一行内容char buf[1024] = { 0 };while (KEY != CString(buf)){ifs.getline(buf, sizeof(buf)); //读取一行内容}ifs.getline(buf, sizeof(buf));StrLine = CString(buf);ifs.close(); //关闭文件return StrLine;
}

通过定位关键词，读取某一行信息，返回CString

//通过定位关键词，读取某一行信息，返回CString
CString fileRW::Read_KeyLine(CString KEY)
{if (!file.Open(GetAppPath() + "./config.ini", CFile::modeRead)){return 0;}CString   strLine = _T("");while (file.ReadString(strLine)){if (KEY == strLine){break;}}file.ReadString(strLine);file.Close();return strLine;
}

通过定位关键词，读取某一行信息，返回string

//通过定位关键词，读取某一行信息，返回string
string fileRW::Read_strLine(string KEY)
{ifstream ifs; //创建文件输入对象ifs.open("../x64/Debug/config.ini", ios::in); //打开文件if (!ifs.is_open()) {cout << "文件打开失败" << endl;return "-1";}string StrLine;//读文件，读取关键词KEY的下一行内容char buf[1024] = { 0 };while (KEY != string(buf)){ifs.getline(buf, sizeof(buf)); //读取一行内容}ifs.getline(buf, sizeof(buf));StrLine = string(buf);ifs.close(); //关闭文件return StrLine;
}

2 删除指定行

/************************************
@ Brief:		删除指定行
@ Author:
@ Created:
@ Return:
************************************/
void fileRW::DelLineData(char* fileName, int lineNum)
{ifstream in;in.open(fileName);string strFileData = "";int line = 1;char lineData[1024] = { 0 };while (in.getline(lineData, sizeof(lineData))){if (line == lineNum){strFileData += "\n";}else{strFileData += CharToStr(lineData);strFileData += "\n";}line++;}in.close();//写入文件ofstream out;out.open(fileName);out.flush();out << strFileData;out.close();
}

3 修改指定行

void fileRW::ModifyLineData(string fileName, int lineNum, string lineData)
{ifstream in;in.open(fileName, ios::in);string strFileData = "";int line = 1;char tmpLineData[1024] = { 0 };while (in.getline(tmpLineData, sizeof(tmpLineData))){if (line == lineNum){strFileData += lineData;strFileData += "\n";}else{strFileData += tmpLineData;strFileData += "\n";}line++;}in.close();//写入文件ofstream out;out.open(fileName, ios::out);out.flush();out << strFileData;out.close();
}