void CTestDlg::OnBnClickedSavedwgButton()
    {
        // TODO: 在此添加控件通知处理程序代码
        CFileDialog openDlg(FALSE,_T("dwg"),NULL,
            OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,
            _T("dwg(*.dwg) | *.dwg|dxf(*.dxf) | *.dxf||"),this);

        CString sAppPath = CTestDlgApp::GetAppPath();

        CString sInitialDir = AfxGetApp()->GetProfileString(_T("MxDWGTestDlg"),_T("SaveDwgDir"),sAppPath );

        CString sFileName;
        openDlg.m_ofn.lpstrInitialDir= sInitialDir; //设置打开文件的缺省路径

        if(openDlg.DoModal() == IDOK)
        {
            sFileName = openDlg.GetPathName();
        }
        else
        {
            return;
        }

        int iFindPos = sFileName.ReverseFind('\');
        if(iFindPos >= 0)
        {
            CString sPath = sFileName.Left(iFindPos + 1);
            AfxGetApp()->WriteProfileString(_T("MxDWGTestDlg"),_T("SaveDwgDir"),sPath);
        }

        if(!MxDraw::SaveDwg(m_hDrawOcx,sFileName) )
        {
            CString sError;
            if(MxDraw::GetLastError().IsEmpty() )
                sError = _T("保存dwg文件失败!");
            else
                sError.Format(_T("保存dwg文件失败!原因为：%s"),MxDraw::GetLastError());
            AfxMessageBox(sError);
        }
        else
        {
            AfxMessageBox(_T("保存成功"));
        }
    }