最后一个参数传true,把Mx_Line命令，当着一个函数调用。
            acDocManager->sendStringToExecute(MxDraw::GetDatabase(MxDraw::GetCurOcxHandle())->GetDocument(),
                _T("Mx_Line"),true,false,true,0,true
                );

            // 得到Mx_Line调用后，绘制的直线id.
            McDbObjectIdArray aryId;
            Mx::mcdbEntitysLastCmd(aryId);
            if(aryId.isEmpty())
                return;

            // 得到虚线的id.
            McDbObjectId lineTypeId = MrxDbgUtils::getSymbolTableRecordId<McDbLinetypeTableRecord>(_T("DASHED"),acdbCurDwg());

            // 修改绘的直线线型。

            for(int i = 0; i < aryId.length();i++)
            {
                McDbObjectPointer<McDbCurve> spCurve(aryId[i],McDb::kForWrite);
                if(spCurve.openStatus() != Mcad::eOk)
                    continue;
                spCurve->setLinetype(lineTypeId);
            }