文本讀寫CStdioFile流文件

char *pFileName="test.txt";
    CStdioFile sf;
    if(!sf.Open(pFileName,CFile::modeCreate|CFile::modeReadWrite|CFile::typeText))
    {
#ifdef _DEBUG
        afxDump<<"Unable to open file"<<"\n";
#endif
        exit(1);
    }
    char aaa[]="aaa\n";//        '\n' :0x0A 
    char *bbb="bbb\12";//        '\12':0x0A
    CString ccc("ccc\15");//    '\15':0x0D
    sf.WriteString(aaa);
    sf.WriteString(bbb);
    sf.WriteString(ccc);
    sf.WriteString("ddd\r");//    '\r' :0x0D
    sf.Close();
    CStdioFile sf2("test.txt",CFile::modeRead|CFile::typeText);
    char buf[8];
    CString str;
    LPTSTR lpstr=sf2.ReadString(buf,8);
    AfxMessageBox(buf);
    while(sf2.ReadString(str))
        AfxMessageBox(str);
    sf2.Close();