AcDbObjectId
    CTestCommands::AddToModelSpace(AcDbEntity* pEntity,AcDbDatabase* pDatabase,bool isAutoClose)
    {
        AcDbObjectId objId;  
        AcDbBlockTableRecordPointer spBlkRec(ACDB_MODEL_SPACE,pDatabase,AcDb::kForWrite);
        if(spBlkRec.openStatus() != Acad::eOk)
            return AcDbObjectId::kNull;
        spBlkRec->appendAcDbEntity(objId, pEntity);

        if(isAutoClose)
            pEntity->close();
        return objId;
    }

    McDbXline* pXLine = new McDbXline;
    pXLine->setBasePoint(bastPt);
    pXLine->setUnitDir(vecDir);
    return AddToModelSpace(pXLine,pDatabase,true);