mfc读取文件

CStdioFile file;//头文件中添加
CString szFilePath;
CString filename_routelist ("key.txt");
if (file.Open(filename_routelist, CFile::modeReadWrite | CFile::typeText))//如果有文件则读取
{
file.SeekToBegin();
file.ReadString(szFilePath);

file.Close();//关闭文件
}


else if (file.Open(filename_routelist, CFile::modeCreate | CFile::typeText | CFile::modeReadWrite))
//如果没有key.txt文件 则在该路径下建立此文件
{
CString  write ("123456");

file.WriteString(write);

file.Close();
}
else
exit(0);