windows編程潘愛民com講座續(xù)介紹一些重要的模式

軟件設(shè)計模式(二軟件設(shè)計模式(二內(nèi)復(fù)習(xí)復(fù)習(xí)：patternDesignpatternsrepresentsolutionstoproblemsthatarisewhendevelo softwarewithinaparticularcontext關(guān)于patternpatternpattern復(fù)習(xí)：如何描述一個模Designpatternname，AliasesorAlsoKnownProblem，IntentorContext，RelatedExamples，Known復(fù)習(xí)：creationalFactory本質(zhì)：用一個virtualmethod完成創(chuàng)建過

Structural一個product族的factorymethod構(gòu)成了一個factory通過product原型來構(gòu)造product，Clone+prototype通過一個構(gòu)造算法和builder接口把構(gòu)造過程與客 單實例類型，如何構(gòu)造這單個實例？如 這單個實例把對象的獲取過程與客

**77Adapter(一Converttheinterfaceofaclassintoanotherinterfacesexpect.Adapterletsclassesworktogethercouldn'totherwisebecause patibleSometimesatoolkitclassthat'sdesignedforreuseisn'treusableonlybecauseitsinterfacedoesn'tmatchthe-specificinterfaceanapplicationrequires.Adapter模式(二youwanttouseanexistingclass,anditsinterfacedoesnotmatchtheoneyouneed.youwanttocreateareusableclassthatcooperateswithunrelatedorunforeseenclasses,thatis,classesthatdon'tnecessarilyhavecompatibleinterfaces.(objectadapteronly)youneedtouseseveralexistingsubclasses,butit'simpracticaltoadapttheirinterfacebysubclassingeveryone.Anobjectadaptercanadapttheinterfaceofitsparentclass.Adapter模式Adapter模式(三Adapter模式(三–、Target、Adaptee、classadapter——objectadapter——

Adapter模式(四

Adapter模式(五class無法adaptadaptee的子類，但是可以重載adaptee的行object可以adaptadapteeHowmuchadaptingdoesAdapterPluggableUsingtwo-wayadapterstoprovide針對classadapter，用多重繼承來實

使用C++繼承機制實現(xiàn)class使用內(nèi)嵌對象技術(shù)實現(xiàn)object使 對操作，供客戶插入？——hook技術(shù)Adapter模式(Adapter模式(六RelatedC++COM中的模式8：Bridge(一Decouplean ionfromitsimplementationsothatthetwocanvaryindependently抽象(接口)與實現(xiàn)都非常。Bridge模Bridge模式(二Applicability：UsetheBridgepattern對一個實現(xiàn)的修改不影響客戶(無須重新編譯Bridge模式(三 ion,ion,Bridge模式(四二進制兼容對客戶隱藏實現(xiàn)細

Bridge模式(五OnlyoneCreatingtherightImplementor如何創(chuàng)建？根據(jù)客戶環(huán)境，或者通過Sharing資源管理 計數(shù)技UsingmultipleRelated–Related–Factory可以用來創(chuàng)建和配置Bridge模–與Adapter–handle：文件handle、窗口插StringRep(constcharintcount;char*rep;Counted

class{String(constStringString&operator=(constStringStringRepComposite模式(Composite模式(三–,Component,Leaf,典型的composite對象結(jié)99：Composite(一Composeobjectsintotreestructurestorepresentpart-wholehierarchiesCompositelets streatindividualobjectsandcompositionsofobjectsuniformly”遞歸組Composite模式(二youwant stobeabletoignoretheindividualobjects.swilltreatallobjectsinthecompositestructureuniformly.Composite模式(Composite模式(四objectsandcompositeobjects。定義了包含leafmakesthesimple。客戶一致地處理復(fù)合對makesiteasiertoaddnewkindsofcomponentscanmakeyourdesignoverlygeneral。使得系統(tǒng)過于Composite模式(五ExplicitparentSharingizingtheComponentDeclaringthechildmanagementShouldComponentimplementalistofChildCachingtoimproveWhoshoulddeleteWhat'sthebestdatastructureforstoringComposite模Composite模式(六Related廣泛應(yīng)用于OO領(lǐng)MFC中的組件層次：ActiveX10：Facade(一Provideaunifiedinterfacetoasetofinterfacesinasubsystem.Facadedefinesahigher-levelinterfacethatmakesthesubsystemeasiertouse.Facade模式(三–Facade模式(三–facade,subsystemApplicability：UsetheFacadepattern FlyWeight模式(三FlyWeight模式(三FlyWeight模式(四Struct(續(xù)–,flyweight,concreteFlyweight,–Facade模式(四—— Facade模式(五Related–facade對象的創(chuàng)建：singleton MFCFakeMFCMapMapMapPluginMDINetscape1111：FlyWeight(一Usesharingtosupportlargenumbersoffine-grainedobjectsefficiently.當(dāng)對象的粒度太小的時候，大量對象將會產(chǎn)生巨大的資源消耗，因此考慮用共享對象(lyegh)來實現(xiàn)邏輯上的大量對象。Flght對象可用于不同的onxt中，本身固有的狀態(tài)不隨onxt發(fā)生變化，而其他的狀態(tài)隨onxt而變化FlyWeight模式(二ofthefollowingaretrue:AnapplicationusesalargenumberofStoragecostsarehighbecauseofthesheertyofMostobjectstatecanbemadeManygroupsofobjectsmayberecedbyrelativelyfewsharedobjectsonceextrinsicstateisremoved.Theapplicationdoesn'tdependonobjectidentity.Sinceflyweightobjectsmaybeshared,identitytestswillreturntrueforconceptuallydistinctobjects.FlyWeight模式(FlyWeight模式(五把對象的狀態(tài)分開：intrinsicand Removingextrinsicstate，盡可能做到實時計算(通過Managingsharedobjects，客戶不能直接實例化 Related與Composite可以用flyweight實現(xiàn)State和Strategy用flyweight實現(xiàn)celltearoff“DesignPatternsStructuralStructuralPatternsStructuralPatternsStructuralpatterns小Adapter、bridge、composite用于構(gòu)造對象組合結(jié)

BehavioralChainofResponsibilityInterpreter MediatorMementoStateTemteMethod12：12：Command(一Action,Encapsulatearequestasanobject,therebylettingyou swithdifferentrequests,queueorlogrequests,andsupportundoableoperations.Command模式(二parameterizeobjectsbyanactiontoperformspecify,queue,andexecuterequestsatdifferentsupportsupportloggingchangessothattheycanbereappliedincaseofasystemcrashstructureasystemaroundhigh-leveloperationsbuiltonprimitivesoperations——transactionsCommand模Command模式(三 Command模式(四

Command模式(五Related模式可用來實 mand組為實現(xiàn)Related模式可用來實 mand組為實現(xiàn)o，可以用其他行為模式來管理狀態(tài)，如模式。 mnd被放到istrylst之前，可以prototype模 自Commandsarefirst-classobjectsTheycanbemanipulatedandextendedlikeanyotherobjectYoucanassemblecommandsintoacompositecommandAnexampleis It'seasytoaddnewCommands,becauseyoudon'thavetochangeexistingclassesHowinligentshouldacommandSupportingundoandAvoidingerroraccumulationintheundoUsingC++tem模式模式 tor(一ProvideawaytoaccesstheelementsofanaggregateobjectsequentiallywithoutexposingitsunderlyingAnaggregateobjectsuchasalistshouldgiveyouawaytoaccessitselementswithoutexposingitsinternalSeparatingthetraversalmechanismfromtheListobjectletsusdefinei torsfordifferenttraversalpolicieswithoutenumeratingthemintheListinterface. tor模式(二 torpatternwhenexposingitsinternalrepresentation.toprovideauniforminterfacefortraversingpolymorphici tor模式(三– tor、 tor模式(四Itsupportsvariationsinthetraversalofan torssimplifytheAggregateMorethanonetraversalcanbependingonanWhocontrolsthe externalitorversusinternaliWhodefinesthetraversal——itor定義算法——itor如何數(shù)Howrobustisthe tor模式(五Implementation(續(xù)Additional tor基本操作：First,Next,IsDone,andUsingpolymorphic tors torsmayhaveprivileged torsforcomposites——適合于internali Null

常被用 posite模式的復(fù)合結(jié)Polymorphici torsrelyonfactorymethodstoinstantiatetheappropriateICOMenumerator：connectableobject、C++在STL中，itor是連接algorithm和container14：14：Observer(一Aliases：Dependents,Publish-Defineaone-to-manydependencybetweenobjectssothatwhenoneobjectchangesstate,allitsdependentsarenotifiedandupdatedautomatically. ThekeyobjectsinthispatternaresubjectandAsubjectmayhaveanynumberofdependentAllobserversarenotifiedwheneverthesubjectundergoesachangeinstateObserver模式(二Whenan ionhastwoaspects,onedependentontheother.Encapsulatingtheseaspectsinseparateobjectsletsyouvaryandreusethemindependently.Whenachangetooneobjectrequireschangingandyoudon'tknowhowmanyobjectsneedtobeWhenanobjectshouldbeabletonotifyotherobjectswithoutmakingassumptionsaboutwhotheseobjectsare.Inotherwords,youdon'twanttheseobjectstightlyObserver模式Observer模式(三–Subject、ConcreteSubject、Observer、Observer模式(四

Observer模式(五Observer模式(六Mediator：用Mediator模Observer模式(六Mediator：用Mediator模式封裝復(fù)雜的更新語COMpropertyCOM+EventSupportforbroadcastUnexpected subjectstotheirObservingmorethanoneWhotriggersthe orMakingsureSubjectstateisself-consistentbeforesubject向observer傳遞變化信中間插入15：15：Strategy(一Defineafamilyofalgorithms,encapsulateeachone,andmaketheminterchangeable.Strategyletsthealgorithmvaryindependentlyfrom sthatuseit.Strategy模式(二manyrelatedclassesdifferonlyintheiryouneeddifferentvariantsofananalgorithmusesdatathat asmultipleconditionalstatementsinitsStrategy模Strategy模式(三Strategy、ConcreteStrategy、StrategyandContextincttoimplementthechosenAcontextforwardsrequestsfromitsstoitsStrategy模式(四FamiliesofrelatedAnalternativetoStrategieseliminateconditionalsmustbeawareofdifferentCommunicationoverheadbetweenStrategyandIncreasednumberofDefiningtheStrategyandContextStrategiesastemteMakingStrategyobjectsStrategy模Strategy模式(五flyweight：考慮用flyweight模式來實現(xiàn)strategy

16：Visitor(一Representanoperationtobeperformedontheelementsofanobjectstructure.Visitorletsyoudefineanewoperationwithoutchangingtheclassesoftheelementsonwhichit 不 不 piler例 TypeCheckGenerateCodePrettyPrintVariableRefNodeAssignmentNodeVisitVariableRefVisitAssignmentVisitVa