毕业论文英文文献及翻译

英文原文ASP.NETandthe.NETFrameworkASP.NETispartofMicrosoft'soverall.NETframework,whichcontainsavastsetofprogrammingclassesdesignedtosatisfyanyconceivableprogrammingneed.Inthefollowingtwosections,youlearnhowASP.NETfitswithinthe.NETframework,andyoulearnaboutthelanguagesyoucanuseinyourASP.NETpages.The.NETFrameworkClassLibraryImaginethatyouareMicrosoft.Imaginethatyouhavetosupportmultipleprogramminglanguages—suchasVisualBasic,JScript,andC++.Agreatdealofthefunctionalityoftheseprogramminglanguagesoverlaps.Forexample,foreachlanguage,youwouldhavetoincludemethodsforaccessingthefilesystem,workingwithdatabases,andmanipulatingstrings.Furthermore,theselanguagescontainsimilarprogrammingconstructs.Everylanguage,forexample,canrepresentloopsandconditionals.EventhoughthesyntaxofaconditionalwritteninVisualBasicdiffersfromthesyntaxofaconditionalwritteninC++,theprogrammingfunctionisthesame.Finally,mostprogramminglanguageshavesimilarvariabledatatypes.Inmostlanguages,youhavesomemeansofrepresentingstringsandintegers,forexample.Themaximumandminimumsizeofanintegermightdependonthelanguage,butthebasicdatatypeisthesame.Maintainingallthisfunctionalityformultiplelanguagesrequiresalotofwork.Whykeepreinventingthewheel?Wouldn'titbeeasiertocreateallthisfunctionalityonceanduseitforeverylanguage?The.NETFrameworkClassLibrarydoesexactlythat.Itconsistsofavastsetofclassesdesignedtosatisfyanyconceivableprogrammingneed.Forexample,the.NETframeworkcontainsclassesforhandlingdatabaseaccess,workingwiththefilesystem,manipulatingtext,andgeneratinggraphics.Inaddition,itcontainsmorespecializedclassesforperformingtaskssuchasworkingwithregularexpressionsandhandlingnetworkprotocols.The.NETframework,furthermore,containsclassesthatrepresentallthebasicvariabledatatypessuchasstrings,integers,bytes,characters,andarrays.Mostimportantly,forpurposesofthisbook,the.NETFrameworkClassLibrarycontainsclassesforbuildingASP.NETpages.Youneedtounderstand,however,thatyoucanaccessanyofthe.NETframeworkclasseswhenyouarebuildingyourASP.NETpages.UnderstandingNamespacesAsyoumightguess,the.NETframeworkishuge.Itcontainsthousandsofclasses(over3,400).Fortunately,theclassesarenotsimplyjumbledtogether.Theclassesofthe.NETframeworkareorganizedintoahierarchyofnamespaces.ASPClassicNoteInpreviousversionsofActiveServerPages,youhadaccesstoonlyfivestandardclasses(theResponse,Request,Session,Application,andServerobjects).ASP.NET,incontrast,providesyouwithaccesstoover3,400classes!Anamespaceisalogicalgroupingofclasses.Forexample,alltheclassesthatrelatetoworkingwiththefilesystemaregatheredtogetherintotheSystem.IOnamespace.Thenamespacesareorganizedintoahierarchy(alogicaltree).AttherootofthetreeistheSystemnamespace.Thisnamespacecontainsalltheclassesforthebasedatatypes,suchasstringsandarrays.Italsocontainsclassesforworkingwithrandomnumbersanddatesandtimes.Youcanuniquelyidentifyanyclassinthe.NETframeworkbyusingthefullnamespaceoftheclass.Forexample,touniquelyrefertotheclassthatrepresentsafilesystemfile(theFileclass),youwouldusethefollowing:System.IO.FileSystem.IOreferstothenamespace,andFilereferstotheparticularclass.NOTEYoucanviewallthenamespacesofthestandardclassesinthe.NETFrameworkClassLibrarybyviewingtheReferenceDocumentationforthe.NETFramework.StandardASP.NETNamespacesTheclassescontainedinaselectnumberofnamespacesareavailableinyourASP.NETpagesbydefault.(Youmustexplicitlyimportothernamespaces.)ThesedefaultnamespacescontainclassesthatyouusemostofteninyourASP.NETapplications:System—Containsallthebasedatatypesandotherusefulclassessuchasthoserelatedtogeneratingrandomnumbersandworkingwithdatesandtimes.System.Collections—Containsclassesforworkingwithstandardcollectiontypessuchashashtables,andarraylists.System.Collections.Specialized—Containsclassesthatrepresentspecializedcollectionssuchaslinkedlistsandstringcollections.System.Configuration—Containsclassesforworkingwithconfigurationfiles(Web.configfiles).System.Text—Containsclassesforencoding,decoding,andmanipulatingthecontentsofstrings.System.Text.RegularExpressions—Containsclassesforperformingregularexpressionmatchandreplaceoperations.System.Web—ContainsthebasicclassesforworkingwiththeWorldWideWeb,includingclassesforrepresentingbrowserrequestsandserverresponses.System.Web.Caching—Containsclassesusedforcachingthecontentofpagesandclassesforperformingcustomcachingoperations.System.Web.Security—ContainsclassesforimplementingauthenticationandauthorizationsuchasFormsandPassportauthentication.System.Web.SessionState—Containsclassesforimplementingsessionstate.System.Web.UI—ContainsthebasicclassesusedinbuildingtheuserinterfaceofASP.NETpages.System.Web.UI.HTMLControls—ContainstheclassesfortheHTMLcontrols.System.Web.UI.WebControls—ContainstheclassesfortheWebcontrols..NETFramework-CompatibleLanguagesForpurposesofthisbook,youwillwritetheapplicationlogicforyourASP.NETpagesusingVisualBasicasyourprogramminglanguage.ItisthedefaultlanguageforASP.NETpages(andthemostpopularprogramminglanguageintheworld).AlthoughyousticktoVisualBasicinthisbook,youalsoneedtounderstandthatyoucancreateASP