对一未命名的文件的读取访问被拒绝

char buff[120]="nihao";
    CFile file;
   // file.Open("D:\\fengyu.txt",CFile::modeWrite|CFile::modeRead);//将出现上面的拒绝
     file.Open("D:\\fengyu.txt",CFile::modeRead);
  file.Seek(0,CFile::begin);
    file.Read(buff,sizeof(buff));
    file.Close();
    CString str1=buff;
    ::AfxMessageBox(str1);