CStdioFile file;
CString filepath;
TCHAR szFilter[] = _T("文本文件(*.txt)|*.txt|所有文件(*.*)|*.*||");
CFileDialog fileDlg(FALSE, _T("txt"), m_txtName, OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT, szFilter, this);
if (IDOK == fileDlg.DoModal())
{
filepath = fileDlg.GetPathName();
file.Open(filepath, CFile::modeCreate | CFile::modeWrite | CFile::typeText);
//
file.Close();
}