MFC读取TXT文件，写入编辑框

void CSerialKF1View::OnFileOpen()
{
// TODO: Add your command handler code here
CFileDialog fileDlg(TRUE);
if(fileDlg.DoModal() == IDOK)
{
CString str;
CFile f;
f.Open(fileDlg.GetFileName(),CFile::modeReadWrite);
f.Read(str.GetBuffer(f.GetLength()),f.GetLength());
f.Close();
GetDlgItem( IDC_SEND )->SetWindowText( str);
}

}