2023年國家制造業(yè)信息化AUTOCAD認證考試樣題

Chaｐter1０ＵsingBlｏcｋandExterｎａlRｅferenｃｅs1０.1OverviewAutoCADprovidessｅvｅralfeａt(yī)urestohelpyｏumａnａgｅobjectsiｎyouｒdｒawinｇs.Withｂloｃksyouｃanoｒganizeaｎdmａｎipulateｍaｎyｏbｊectsasoｎecoｍponent．Youcanａlsｏassocｉatｅｉtｅｍsｏfｉnformａt(yī)ionwitｈtheｂlｏckｓinyourdrawiｎｇs-ｆorexample，parｔnumｂersandprices-bｙaｔtacｈingａt(yī)tributes．Sｐecificationｓheetｓorbilｌｓoｆmａt(yī)erialscanｂecreateduｓingtｈisｉｎｆｏrmation.YｏucanattachoroverlayｅntｉredrawｉnｇsｉnｙoｕｒｃｕrrenｔdrawｉnｇｂyusinｇAｕtoCAＤexteｒnａlrｅｆerences,orxrefｓ.Ｗhenyouopｅnａdraｗingtｈatconｔａinｓxrefs,ａｎychaｎgｅsthathaｖebeｅnmａdeｉntｈereferencedｄrａwingappeａｒiｎthecuｒrｅnｔｄrawiｎg.1０.２ＷorkiｎgwithBlocksＡｂlockisａcｏllectionofobｊectsｙｏｕcanａsｓoｃiａt(yī)etｏgｅthertoformasingleobjecｔ,oｒbloｃkdefinｉtion.Youcaniｎseｒｔ,scalｅ，aｎdrｏtaｔeablocｋinadrawing.Youｃanexpｌoｄeａｂlocｋｉｎtoiｔｓcomｐｏnentｏbjｅcts,mｏdifythｅm，andredefｉnetheblock.AutoCADuｐdateｓallcurrentａndfuturｅiｎstaｎcｅsｏｆthatblｏcｋｂasｅdoｎtheblockdeｆｉnition.Ｂlｏcksstｒｅamlinｅｔhedraｗingｐｒocesｓ．Forexample,youcａｎuｓebｌocｋｓtoBuｉlｄastandａrdlibraryoｆｆrｅｑueｎｔlyusedsymbｏls,coｍｐoneｎts,oｒstandardparｔs．Youcaｎinseｒｔthesaｍeｂlocknumerousｔiｍｅsｉnsteadoｆrｅ-cｒeaｔingｔhedrawiｎgeleｍｅntseachtime. Ｒeviseｄraｗingseｆｆiｃｉeｎtｌyｂyｉnserting,rｅｌｏcatinｇ,aｎdｃｏpyingblocksascｏmpｏｎｅｎtsraｔhertｈaｎｉndiｖidｕalgeometrｉcobjectｓ. Savｅdisｋｓpacebysｔorｉｎｇallｒeferenｃｅstｏthesameblockasoneｂlockdefinｉtiｏｎinｔheｄrawｉngdaｔaｂase.Ｆｏｒinｆormａt(yī)iｏnaboutｈowtocrｅateaｂloｃｋ,ｓｅe＂DefiｎingBlocks."Wｈenｙoｕinｓertabｌoｃｋｉnyouｒdｒａwinｇ,youarecｒeatingaｂloｃkinｓtance.Eachtimeｙoｕinsｅrtａｂlockinsｔance,ｙouaｓsigｎascalｅｆaｃｔorandrotatｉoｎaｎgletｏtheinseｒteｄｂlock.Youcａnalsｏscaｌｅａbｌocｋｉnstａnceusingdiffｅrｅntvalueｓinanｙｃoordinａt(yī)e(X，Y,Z)ｄirｅｃtion.Blockｓmaｋeｉtpoｓsibleforyｏutoorganizeyoｕｒｄｒawinｇｔasｋsiｎasystemａｔiｃway,soｔhatyoucansｅtup，ｒedｅsigｎ，andsorｔtｈeobｊeｃtsiｎyourｄraｗingｓaｎdｔｈeｉnfoｒmatｉoｎａssociａｔedwitｈｔhem．DｅfｉningBlocksＹouｃａｎgroupobｊectstoｃｒeatｅｂlockｄefinitｉonsintｈecｕrreｎtdraｗing，oryoｕcansavethｅｂlｏｃkasaseparatedｒaｗinｇｆｉle.Wｈeｎｙoudeｆiｎeａbｌｏｃk,ｙouspeｃｉｆyｔheｂａsepoint,theobｊectstoｇrouｐ,anｄwｈeｔhｅrtｏretａinordeleｔethｅobjｅcｔsｏrcｏnｖerｔthemtoａbｌoｃkinthecｕｒｒｅnｔｄrａｗinｇ.Youcanalsoenｔerａt(yī)ｅxtdescｒiptｉonａndspecｉfyaｎicｏnuｓedtｏhｅlpiｄeｎtifythｅblｏckdeｆinｉｔiｏninＡutoＣＡDDesignCｅnter.Ｂlｏckｄefiｎitionｓａreoneｏｆmanynongrapｈicalobjｅctssaｖedinadrａwing.See"WｏrkｉｎgwitｈNaｍeｄObｊects."Ｔｏcreａt(yī)eabloｃkdｅｆｉnｉｔiｏn1?ＦroｍtheDrａｗｍenu,chooseＢｌockMake．2?ＩntheBｌockDeｆiniｔiｏndiａｌoｇbox,enｔｅranameｆｏｒthｅblｏcｋ.3?UndｅrObjｅｃts,choｏｓｅtheＳelectObjecｔsbｕttｏｎtousethｅpointｉｎgdevicetｏｓｅlectoｂjeｃtsfｏｒtｈｅｂlocｋｄｅfiｎｉtiｏn.Thedialogboxｃlｏsestemporａrｉｌywｈileyｏuselｅｃｔobｊectsｆoｒtheｂlｏｃk.PressENＴEＲｗｈeｎyouaｒedｏnｅsｅlｅctingbloｃks.Theｄiａloｇbｏxrｅｏpenｓ.4?Iｆyouwaｎttoｃreateaselｅｃtioｎset,usetheQｕｉcｋＳeleｃtｂuttｏｎtocrｅaｔｅｏrｄefiｎeａfiｌｔerforyoursｅｌeｃtionseｔ.See"ＦiltｅriｎｇSelectionSets."5?UnderObｊects,specifywｈetｈertoretａiｎ，convｅrtｔｏａblock,orｄｅｌetetheselectedoｂｊeｃts．Rｅｔaiｎ:Kｅepｓselｅctedｏbjｅctsｉntheｃurrentdrawinｇ,iｎtｈeｉroriginalｓｔａｔe.ConveｒｔｔoBloｃk:Rｅplａcesselecteｄｏbjectsｗithaｎinｓtancｅofｔhebloｃk．Delｅtｅ:Ｒeｍｏvessｅlecｔedｏbjｅctsafteｒtheblｏckisdefｉned．6 UnｄerBaｓeＰoint,ｅnｔｅrthｅcoordinatevaluｅｓｆortｈｅｉnｓerｔiｏnbａseｐointｏrｃhoosｅtheSpecifyＩnｓeｒｔionBasePｏiｎtbuttontousethepoinｔｉｎｇdｅvice.7?ＵnｄerDesｃrｉｐtiｏn,entertextｔohelpidenｔifyｔheblockｆoreasyretrievaｌ．8?UndｅrIcon,sｐecifywhｅtｈｅｒtocreateanicoｎfｒｏｍｔhｅblockdefinitiｏn.Donotｉｎcludeａnicon:Omiｔspreviewiｍａｇefｒｏmｂｌｏckｄefｉｎｉtiｏn.Cｒeａt(yī)eiｃoｎfrombｌocｋgeｏmetry:Saveｓｐreｖiｅｗimagewｉththebloｃkdefinitiｏn.９ ChoｏseOK．Theblocｋdｅfiniｔionissavedintｈecuｒreｎtdrawｉｎg．Tｏsａveablockorobｊeｃｔasａseｐarａt(yī)edｒawingfile1 AttheComｍanｄｐrompt,ｅnteｒwbloｃk.２ InｔｈeＷrｉtｅBｌocｋdiａlｏｇbox，specifｙabｌｏckorａnｏｂｊｅｃtｔowrｉteoｕｔａsａfiｌe.Block:Specifiesablocｋtosaveａsａfile. EntireDrａwｉｎg:Sｅｌｅｃtscuｒrｅntdrａwingaｓablock.?Oｂject:Speciｆiesobjeｃtstobesavedasafile. 3?ＵnｄerBｌock,seleｃtanamefｒomthｅlisttｏsaveasafiｌe.4?UnderBasePoint，uｓethePiｃｋPointbuｔtｏｎtodefiｎethｅbasｅｐoint．５ UnｄerOｂjecｔs，useｔheSeleｃtｏbｊecｔsbuｔｔoｎtｏseｌｅｃttheobjｅctfoｒthｅblocｋfile．6 Eｎteranamｅfortｈenewｆｉｌｅ.Ifabｌockisselected,WBLOCKaｕtomａt(yī)ｉcａllyusesthatbｌｏｃｋ'snamｅfoｒtｈenｅwfilｅ.7 InｔheＩnsertUｎitｓlisｔ,selecｔanｉnｓertunitｔouseiｎＡuｔｏＣADDesignCｅｎter．8 ChooｓeOK.Theblocｋdefiｎｉｔioｎiｓｓavｅｄasadｒawingｆile.InserｔingＢloｃｋsＹoucanｉnｓertｂlocｋsｏｒeｎtireｄrawiｎｇsiｎｔothecｕrrentｄraｗingwithINＳＥＲT.Whenyｏｕinsertaｂlockoｒdrawinｇ,yousｐecifｙtheinsertiｏｎpoiｎt,scａle，aｎdｒotationａngle.ThissectionexpｌaiｎｓinsertingbｌocksinｔｏyourｄrａwinｇｕsingINSERT.Sｅe"ＵsinｇAuｔｏCADDesｉgnCeｎtｅrｔｏInsertBｌocks."Whenyｏuinsｅｒtaｎentiｒedrａwingintoａnotｈerdｒaｗinｇ,AutoCＡDtreatstheｉnｓeｒteｄｄrawinglikｅaｎyｏtherｂlｏckｒefeｒence.Subｓｅquｅntinsertｉonsｒeｆeｒencetｈeblｏckdeｆiｎiｔion(ｗhｉchｃontａinsｔheｇｅoｍetｒicｄｅsｃriptioｎｏｆthebｌock)ｗｉｔｈdｉｆｆerentposition,sｃalｅ,andrｏtatｉｏnsettings,aｓshowｎintｈefolloｗingillusｔraｔｉon.Ifyoucｈangetｈeoｒｉｇinaldrawingafteｒinsｅrtingit,tｈeｃｈangeshａvenoeffectｏnｔheinsｅrteｄblocｋ.Ifyｏuwanttheinｓｅrteｄbｌockｔoｒｅflｅｃtthｅchangesｙoｕmaｄetｏｔheoriginaｌdrawｉnｇ，ｙoucａnｒｅdeｆｉnetheblockbyreinｓｅｒtiｎgｔheoriginａldrawing.Ｉfyouｗantｔｏｉnｓeｒｔadrawingbutｙoudon'ｔwaｎtｔｈeｆilenameｔｏbｅthesameasｔhebloｃknａmｅ,ｙouｃaｎｉｎsｅｒtitusiｎgａｂlockname=fiｌeｎamｅsｙntaxatｔｈｅBlockＮａmepromｐt.Bｙｄefaｕlt，ＡｕtｏCADusesthecooｒdinatｅ0，0，0ａstheinsｅrtioｎbaseｐointfｏｒinseｒteddraｗｉngs.YouｃanchangetｈeinsｅrｔionｂaseｐｏiｎｔｏfaｄrawingbｙｏpeninｇtheorigiｎalｄrａｗinganｄusｉngBASＥtospecifyadiffｅrｅntinsｅrtionbasepoｉnt.ＡutｏCADusesｔhenewbasepｏｉｎｔtｈeｎeｘｔｔiｍeyouinserttheｄｒaｗｉng.Ifｔｈedrawingyouiｎsertｃontainsｏbjectscreaｔedｉnapaｐeｒｓｐaｃelaｙoｕｔ，thoseoｂjectsareｎotｉncｌuｄediｎthecurreｎtdraｗing＇sbｌocｋdｅfinｉtｉon.Tousetheｐaｐerspaｃeｏbjｅctｓｉnaｎotheｒｄrawiｎg，opｅｎtｈeorｉｇiｎaldｒawingaｎｄuｓeBLOＣKｔodeｆinethepａｐerspaceｏbｊeｃtｓasablock.Ｔｈeblockisｎｏwdｅfineｄwｉthinyourｄrａwｉｎｇ.Yoｕcaninsertthｅdrawingintｏａnotｈerdrawingaｎdinsertｔhebloｃkdｅfineｄｉｎyｏurorｉginalｄrawiｎgｉneｉtherpaｐeｒｓpaｃeorｍｏdｅlsｐaｃe.WiｔhＡutoCADDesigｎCenter,youｃandispｌaylaｙoutsａnddragｔhemiｎtoyｏｕrdrawiｎgｓ.Sｅe"WorｋingwiｔhDrawingＣｏnｔeｎt．＂Toｉnｓｅｒtablockreｆeｒｅncｅ1?FromtｈｅInｓｅｒtmｅnｕ,chooseBloｃｋ.2?IntheIｎsertdialoｇbｏx,sｐecifyｔhｅｂlocknａｍｅ,ｗhereyｏuｗanｔtoinｓｅrｔiｔiｎtｈecurｒenｔdrａｗing,anｄwhetherｙouｗaｎｔtoexplodeitａfterinｓｅrtion．3?Ifｙｏuhａｖeｍodifｉedtheorigｉｎaldrawinｇｆｉlefoｒablｏｃk,ｙouｃanredefｉneｔhebloｃkinthecurrｅｎtdrawinｇbychoｏｓingFiletoｌｏcaｔｅthefilefｏrtheｂlｏcｋ.4 ChｏoseOK.Theblockreferｅnceisupｄatedinthecｕrrentｄraｗing.ExplodｉngａBlockUseEXPＬODEtobreakａblocｋinsｔａｎｃｅ.Ｂｙｅxplｏdｉnｇａblｏckinstanｃｅ,youcａｎmｏdifyｔheblockoraｄdtoｏrdｅleteｔｈeｏbjecｔｓtｈａｔdefineiｔ.1０.3?WorkingｗiｔhAttriｂuｔｅｓAｎatｔｒiｂｕtｅpｒovidesalabelｏｒｔａgforｙouｔoatｔａchtｅxttoabｌｏck．Wｈeneverｙｏuｉｎsertablｏckthａt(yī)hasavariａbleatｔribｕｔｅ，AｕtoCADprompｔsyoutoeｎterｔhedatａｔｏbesｔoredｗiththeblｏck.Examplｅsofｄatａareｐａrtnumbｅrs，ｐrices,ｃommｅnts,andowners＇ｎamｅｓ.Yｏucanextrａctaｔtｒibｕteiｎｆormaｔioｎfrｏmadｒａｗinganｄuｓethａt(yī)inｆoｒmationinaspreadsheetordaｔaｂasetoproduｃｅitemssuchａsapartslisｔorａbillofmateriaｌs(BOM）.Yoｕcanａssoｃｉatemorethanoneａt(yī)ｔｒiｂutewｉthablock,pｒoｖｉdｅdｔhateaｃhattｒｉbｕteｈａｓａdifｆerｅnｔtag．AutoＣADpromｐｔsyoｕfoｒthevaｌｕｅofｅachattrｉbｕteｗheｎｙoｕiｎseｒtthebｌｏck.Yｏｕcaｎalｓodeｆｉｎecoｎstantattriｂutes:becａｕｓetheyhavethesaｍevaluｅinevｅryｏccurrenceofｔheblock,AutoCＡDdoｅｓnｏtpromｐｔforavaｌuewｈenｙouｉnserttheｂｌｏｃk.Attribuｔescanｂｅiｎｖisibｌe,whichmeanstheatｔributeｉsnotdisｐlayeｄorplｏtteｄ.However,informaｔｉoｎｏnｔheａt(yī)ｔribｕteisｓtoｒediｎtｈedｒawｉngｆｉleanｄwrittｅｎtoａnｅxtractfilｅbyAＴTEXＴ．Cｒｅａt(yī)ｉｎｇAtｔrｉbｕｔesTocreateanａｔｔribute,ｙｏumustfｉrｓｔuｓｅAＴTDＥFｔocｒeateanattｒｉbuｔedｅfinition,wｈicｈdeｓcriｂesｔhｅchaｒacｔerｉsｔｉcsoftheattribｕte.Ｔｈｅcharactｅrｉstｉcsincluｄｅｔｈetag,prompt,valueｉｎfoｒｍatｉon,texｔformaｔtinｇ,ｌocaｔｉon,anｄanｙoptiｏnalｍodes.Tocreａt(yī)ｅａnattｒｉbutedｅfiｎition1?Ｏnthｅｃommａndlｉnｅ，enteｒattdeｆ．2?InｔhｅAｔtｒiｂuｔeDｅfｉｎｉtｉondialogbｏｘ，ｓpeciｆyｔｈeｉｎsertｉonpoiｎｔaｎdｓｅttheattrｉbｕｔｅmodesanｄthetag,pｒompt,anｄｔextoptｉons．3?CｈｏoseOＫ.Aｆtｅrcrｅatｉngtheatｔributｅdeｆinition,youｃansｅlｅｃtitaｓanoｂjectiｎablockdｅｆinitiｏn.Iｆtｈeattriｂutedeｆｉｎitｉonisincｏrｐorateｄｉntoａblocｋ,ｗｈeneveryoｕinseｒtthｅｂloｃk,AutoCADprｏmptsyouwithtｈｅtextstrｉｎgyｏuｓpecｉfｉedｆortheａt(yī)ｔｒibute.Eａchsｕbsequenｔiｎstａｎｃeoｆthｅｂlockcanhaveadｉffｅrｅntvaluespecｉｆiedｆｏrtheａt(yī)tribute.Ifyｏuwaｎttｏuseseｖeraｌattriｂｕteｓtｏgethｅr,ｃｒeａt(yī)ｅeacｈonesepａratelyanｄtｈｅniｎcｌuｄethｅminthｅsameblｏｃk.Ｔｏcｏｎtrolｔheｏrｄerofpｒomptsformultipleatｔributｅs,ｓeｅＯＰTIONSinｔheCommaｎdＲefｅｒｅnce.ＳysｔemvａriａblesAFLAGSsetｓtheATTＤＥFｍode.ATＴDISPgloballycｏntrolｓthevisｉbilitｙofaｔｔributes.ＡTTREＤＥFrｅdefinesablocｋandupdatesaｓｓｏciatｅdaｔtｒibutes.EｄitingAttriｂutｅDefｉｎｉtiｏnsYｏｕcanｕseＤDＥＤITtoeditａｎattriｂutｅdefinitionbefｏｒeｉtisaｓsociaｔeｄｗithablock.Toediｔanａｔtrｉbuteｄefｉnitｉonbefｏｒeｉtｉsassociateｄwithａbloｃk1?FroｍｔheMｏdifymenu,cｈｏｏsｅTｅxt２ Sｅleｃttheattribｕtｅtoｅｄｉt.3?IntheEdiｔAttriｂｕｔeＤefiniｔｉonｄialogｂox，ｓｐｅciｆytｈeatｔribｕtｅｔag,prｏｍpt,anｄｄeｆaｕlｔvalｕe.ThenchooseOＫ．CｏmｍaｎdlineDDEDITReｌateｄCHANGEedｉｔsattrｉbutedefｉniｔｉonｓ．AｔｔａchｉngＡttｒｉbuｔestoBloｃkｓYoｕｃaｎattacｈattribｕｔestoablｏcｋwｈｅnyoｕdｅfinｅorｒedefinethaｔｂｌock.WｈenAutoＣADprｏｍptｓyoutoselecｔtheobjeｃtstoiｎｃludeｉntheblｏｃkdefiniｔiｏn,inclｕdetｈedｅｓiredａｔｔrｉｂｕｔesｉnthｅseｌectioｎseｔ.Ｔhｅｏrｄerｉｎwhicｈｙoｕｓeｌecｔthｅatｔributesdeｔｅｒmiｎeｓtheordeｒinｗhiｃhyoｕareproｍpteｄｆoｒａt(yī)triｂｕteinｆormatiｏnwｈenｙouｉnsｅｒttｈｅｂloｃk（ｓｅｅ"ＤeｆinｉnｇBｌockｓ＂）.EｄitingＡttｒibｕｔｅｓAtｔacｈeｄｔｏBlocksYｏｕｃanediｔatｔriｂｕtesｔhataｒealreadyattaｃheｄtoabloｃｋａnｄｉnｓertｅdinadrａwing.Toedｉｔanattｒibuteaｔtachedｔｏablocｋ1 FromtheModifymenu，chooｓeAttribuｔｅSinglｅ.2?Ｓｅlｅctａbloｃkｔoediｔ．３?IntheＥｄiｔAtｔribuｔesdialogboｘ,ｅdｉttｈｅａｔtribｕteinfoｒmaｔioｎａsｎeｃessary.４ ChooseＯK．Ｔｏcontｒoltｈeorderofprompｔｓｆoｒmultipｌeaｔtrｉｂutes,ｓｅeOＰTIONSinthｅCｏｍmａndRｅfeｒeｎcｅ．10.4UsｉngExteｒｎaｌRｅｆerenｃesAnexteｒnalrｅferｅｎｃｅ(ｘｒｅf)linkｓanｏｔherdrawinｇtothecｕrrentdraｗiｎg.Ｗｈｅｎyｏuinsertaｄrａwiｎgasaｂloｃk,ｔheblocｋdefinｉｔｉｏnandalloｆtheaｓsoｃiateｄｇeｏｍｅtryarestoredinthｅcuｒrenｔdｒawingｄａt(yī)abaｓe.Tｈebloｃｋisnoｔupｄａt(yī)ｅdｉftｈｅoｒigｉnaldrawｉngchａnges．Ｗｈenyouinseｒtadrａwingasａｎxreｆ,howevｅr，tｈｅxrefｉsupdatedwhｅntｈeorigｉnaldrawｉngｃhanges.Aｄrawingcontaiｎingxrefsalwａｙsrefleｃtsthemｏstcuｒｒｅnteｄitinginｅacｈexｔernaｌlyreｆerencedfｉlｅ.Likｅａｂlockrefｅrence,aｎxrefisdispｌayｅｄinthecuｒrｅnｔdrａwingaｓａsｉnｇｌｅobject.Ｈowever,ａnxrｅfｄｏesｎｏtsigｎificantlｙincｒeaｓｅtｈｅfiｌesｉzeoｆtｈecurrｅntdrａwingandcanｎotｂeexpｌodeｄ.Aswithｂlocｋrefeｒences,youｃannestxrｅfｓthａt(yī)arｅａt(yī)tａcｈedtoyourdｒaｗing.Byattachingxｒefs，yｏuｃanAssemｂleａｍａsterdｒawinｇfromcｏmpoｎentdrａwingsthａt(yī)ｍayunderｇocｈanｇesasaprｏjectdｅveloｐｓ.Ｃｏｏrdinatｅyoｕrworｋwitｈtheｗｏｒkｏfoｔｈeｒsｂｙoverｌayｉngotｈerdrａｗｉｎｇsonｙouｒｄrawinｇtoｋeepｕｐwitｈtｈｅcｈangeｓｂｅｉngｍadｅbyothｅrｕserｓ.Eｎsurｅthattｈemoｓtrｅcｅｎtveｒsioｎofｔherｅferenceｄdrawingisdｉｓplayｅd.Wｈenyouoｐenoｒｐｌoｔｙoｕrｄrawｉng,AutoCADautoｍaｔｉcalｌｙｒeｌoadseacｈxｒef，sotheｄraｗingｒｅflｅｃtstｈeｌatesｔchaｎｇestoｔhｅｒeｆerenceddｒawingｆiｌe．Dｉsplaｙonｌyasｐecificｓectionｏfthexrefｆileinｔhemasｔeｒdraｗingbｙcrｅatinｇclｉｐpｅｄbouｎdarieｓｏｆxｒefs.10．5ＣｌipｐiｎgBlocksaｎdＸｒefsAｆtｅrattａchingaｄrａｗingaｓanｘreforinsertingablock,yoｕcandｅfineaclipｐiｎgbｏｕndａryｂyusｉngXCLIP．Aclippingbｏunｄａrｙcanｄefinｅａｐoｒtioｎｏfablockorｘｒeｆｗｈiｌeｓupprｅssingｔhedｉｓplaｙofgeoｍetryouｔsｉdｅoｆtｈeｂoundary.Cｌippｉngaｐpliestoaｎiｎdividｕalinstanｃeｏｆaｎｘreｆ,notthexrefdｅfiｎitionitsｅlf.Thepｏrtionofthｅxｒefｏrblocｋwithintheclｉｐｐedｂounｄaryrｅmaiｎsｖiｓiｂle,aｎdtｈｅremaｉnｄerofｔheｘrefoｒblockｂecomeｓinｖisiｂle.Tｈereferencedgeｏmetryiｓｎｏtalｔerｅd，ｏnlｙｔｈedisplayofｔhexreｆiseditｅd.YoucaｎuｓｅＸCLIPtｏcｒeａt(yī)eanewclｉppiｎｇboundａry，dｅｌetｅanexｉstinｇboｕndary,orgenerateapolｙlineoｂjｅｃtcoiｎcｉdentwithvertｉcesofthｅcｌiｐpｉngｂｏｕndary．Xｒeｆclipｐinｇcanbetｕｒnｅdoｎoroff．Whenaclｉppingbounｄａryisｔurｎedｏff,theboｕndaｒｙisnotdｉsplａyedandtheｅntirexrefｉsviｓible,prｏｖidedthaｔｔhegeomｅｔryisonalayerthatｉsonanｄｔｈawed.Whｅnacｌｉppingboｕndaryistuｒnedｏff,itstｉｌlexistｓaｎdcaｎbｅｔurｎｅdon.Ｈowever,dｅletingaclippingboundaryispermanｅｎt.FｏrmoreinfoｒmaｔｉｏnａbouｔXCLＩP,seeｔｈeＣｏｍmandＲｅfｅrｅnｃe.Afteranxｒefｏｒblockhａsbeeｎｃlipｐｅd,itcａｎbｅeditｅd,ｍｏved,orcoｐieｄjustlikｅanuｎclippeｄxreｆｏｒblock.Ｔheｂoｕndarymovesｗitｈｔherefeｒence．Ifａnxreｆcｏｎtａiｎsnestedｃlippedxrｅｆs，thｅｙａppearcliｐｐediｎthedrａｗｉｎｇ.Ifｔhepareｎｔxｒefiｓｃｌippｅd，theneｓtｅdｘreｆsareａlsoclｉpped.Iｆyouwaｎｔtoseetｈeclｉpｐingｂｏuｎdary，youｃantｕrｎonthｅＸCLＩPFRＡMEｓｙｓｔeｍvａrｉable.XCＬＩPFRAMEdeｔerminesｗhetｈeｒtheclippingbounｄaryｆｒａｍeｉsdｉsplayed.Whenｔheclipｐｉngｆrameison(settｏ1),iｔcaｎbesｅlecｔeｄaｓｐarｔofthｅobjectanｄplotted.Foｒｍoreinfｏｒmａt(yī)ioｎaｂoｕtＸCＬIPFRAME,seetheＣommａndRｅfｅrence.１0.６ＥditingRefｅrenｃeｓinＰl(wèi)aceYoucanmodｉfyexｔｅrｎalreｆｅｒeｎcesanｄredefiｎebｌｏｃkdeｆinitionsfｒｏmwiｔhintｈecｕrrentdrawｉngbｙusinｇin-placeｒｅｆｅrenceｅditing．Ｂｏthbｌocksanｄxrefsaｒｅconsidｅrｅdrefereｎcｅｓ.Ofｔeｎ,ａdrawingcontainsoneｏrｍorｅxrefsaswｅllasmulｔｉpｌeblocｋｒｅfeｒences.Whｅnｗorｋｉｎgwithblocｋreferenceｓ,youcanseｌectablｏｃｋ,ｍｏｄiｆｙit,andupdatethebｌockｄｅfinｉtion.Whenworkingwitｈxrefs，ｙoucａｎuseｉn-plａceｒｅferｅnceedｉtingtｏseｌｅcｔtｈerｅferenｃeyｏuwaｎttoｗorkｗiｔh，modifyitｓｏbｊｅｃts,aｎdsavebａｃｋthｅchａnｇestothｅrｅfeｒｅncedrawing.Yｏｕcanｍaｋeminoｒｃhaｎgeswｉｔhouthaｖingtogｏｂaｃkan