void Vc2005Dlg::DoDrawOrder()
        {
            // 选择实体。
            MxDrawXLib::IMxDrawUtilityPtr mxUtility;
            mxUtility.CreateInstance(__uuidof( MxDrawXLib::MxDrawUtility ));
            if(mxUtility == NULL)
            {
                return;
            }

            // _bstr_t sPrompt(_T("请选择实体"));
            CComPtr<IMxDrawPoint> spPickPoint;
            IMxDrawEntityPtr spEntity = mxUtility->GetEntity(&spPickPoint,_T("请选择实体"));

            if(spEntity == NULL)
                return;

            // 把实体设置成，最下面去。
            m_ocx.SetEntityDrawOrder(spEntity->GetObjectID(),-100);
            long lOrder = m_ocx.GetEntityDrawOrder(spEntity->GetObjectID());
        }