CString str,str2,str3;str2="dsf",str3="dsfds";CStdioFile myFile, File;if(myFile.Open(_T("D:\\filename.txt"), CFile::modeRead)){    //读取    myFile.ReadString(str);     myFile.Close();}else{    //创建    File.Open(_T("D:\\filename.txt"), CFile::modeWrite | CFile::modeCreate);      File.WriteString(str2);    File.Close();} //写入File.Open(_T("D:\\filename.txt"), CFile::modeWrite );      File.WriteString(str3);   File.Close();