CFile文件读取

void ChuffmanDlg::OnBnClickedButton1()
{
    // TODO: 在此添加控件通知处理程序代码
    CFileDialog fd(TRUE);
    CString filename;
    CFile fileread;
    if (fd.DoModal()==IDOK)
    {
        filename=fd.GetPathName();
    }
    fileread.Open(filename,CFile::modeRead); //不要用modeText，用了就错
    int filesize=fileread.GetLength();
    fileread.Read(huffword.GetBuffer(filesize),filesize);
    huffword.ReleaseBuffer();
    m_edit1=huffword;
    fileread.Close();
    UpdateData(FALSE);
}