c#外文文献以及翻译Word格式.docx

c#外文文献以及翻译Word格式.docx

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Inonesense,C#canbeseenasbeingthesamethingtoprogramminglanguagesas.NETistotheWindowsenvironment.JustasMicrosofthasbeenaddingmoreandmorefeaturestoWindowsandtheWindowsAPIoverthepastdecade,VisualBasicandC++haveundergoneexpansion.AlthoughVisualBasicandC++haveendedupashugelypowerfullanguagesasaresultofthis,bothlanguagesalsosufferfromproblemsduetothelegaciesofhowtheyhaveevolved.

InthecaseofVisualBasic6andearlier,themainstrengthofthelanguagewasthefactthatitwassimpletounderstandanddidn’tmakemanyprogrammingtaskseasy,largelyhidingthedetailsoftheWindowsAPIandtheCOMcomponentinfrastructurefromthedeveloper.ThedownsidetothiswasthatVisualBasicwasnevertrulyobject-oriented,sothatlargeapplicationsquicklybecomedisorganizedandhardtomaintain.Aswellasthis,becauseVisualBasic’ssyntaxwasinheritedfromearlyversionsofBASIC（which,inturn,wasdesignedtobeintuitivelysimpleforbeginningprogrammerstounderstand,ratherthantowritelargecommercialapplications）,itdidn’treallylenditselftowell-structuredorobject-orientedprograms.

C++,ontheotherhand,hasitsrootsintheANSIC++languagedefinition.Itisn’tcompletelyANSIcompliantforthesimplereasonthatMicrosoftfirstwroteitsC++compilerbeforetheANSIdefinitionhadbecomeofficial,butitcomesclose.Unfortunately,thishasledtotwoproblems.First,ANSIC++hasitsrootsinadecade-oldstateoftechnology,andthisshowsupinalackofsupportformodernconcepts（suchasUnicodestringsandgeneratingXMLdocumentation）,andinsomearchaicsyntaxstructuresdesignedforthecompilersofyesteryear（suchastheseparationofdeclarationfromdefinitionofmemberfunctions）.Second,MicrosofthasbeensimultaneouslytryingtoevolveC++intoalanguagethatisdesignedforhigh-performancetasksonWindows,andinordertoachievethatthey’vebeenforcedtoaddahugenumberofMicrosoft-specifickeywordsaswellasvariouslibrariestothelanguage.

TheresultisthatonWindows,thelanguagehasbecomeacompletemess.JustaskC++developershowmanydefinitionsforastringtheycanthinkof:

char*,LPTSTR,string,CString（MFCversion）,CString（WTLversion）,wchar_t*,OLECHAR*,andsoon.

Nowenter.NET—acompletelynewenvironmentthatisgoingtoinvolvenewextensionstobothlanguages.MicrosofthasgottenaroundthisbyaddingyetmoreMicrosoft-specifickeywordstoC++,andbycompletelyrevampingVisualBasicintoVisualBasic.NET,alanguagethatretainssomeofthebasicVBsyntaxbutthatissodifferentindesignthatwecanconsiderittobe,forallpracticalpurposes,anew

language.It’sinthiscontextthatMicrosofthasdecidedtogivedevelopersanalternative—alanguagedesignedspecificallyfor.NET,anddesignedwithacleanslate.VisualC#.NETistheresult.Officially,MicrosoftdescribesC#asa“simple,modern,object-oriented,andtype-safeprogramminglanguagederivedfrom

CandC++.〞Mostindependentobserverswouldprobablychangethatto“derivedfromC,C++,andJava.〞Suchdescriptionsaretechnicallyaccuratebutdolittletoconveythebeautyoreleganceofthelanguage.Syntactically,C#isverysimilartobothC++andJava,tosuchanextentthatmanykeywordsarethesame,andC#alsosharesthesameblockstructurewithbraces（{}）tomarkblocksofcode,andsemicolonstoseparatestatements.ThefirstimpressionofapieceofC#codeisthatitlooksquitelikeC++orJavacode.Behindthatinitialsimilarity,however,C#isaloteasiertolearnthanC++,andofcomparabledifficultytoJava.Itsdesignismoreintunewithmoderndevelopertoolsthanbothofthoseotherlanguages,andithasbeendesignedtogiveus,simultaneously,theeaseofuseofVisualBasic,andthehighperformance,low-levelmemoryaccessofC++ifrequired.SomeofthefeaturesofC#are:

❑Fullsupportforclassesandobject-orientedprogramming,includingbothinterfaceandimplementation

inheritance,virtualfunctions,andoperatoroverloading.

❑Aconsistentandwell-definedsetofbasictypes.

❑Built-insupportforautomaticgenerationofXMLdocumentation.

❑Automaticcleanupofdynamicallyallocatedmemory.

❑Thefacilitytomarkclassesormethodswithuser-definedattributes.Thiscanbeusefulfordocumentation

andcanhavesomeeffectsoncompilation（forexample,markingmethodstobe

compiledonlyindebugbuilds）.

❑Fullaccesstothe.NETbaseclasslibrary,aswellaseasyaccesstotheWindowsAPI（ifyou

reallyneedit,whichwon’tbeallthatoften）.

❑Pointersanddirectmemoryaccessareavailableifrequired,butthelanguagehasbeendesigned

insuchawaythatyoucanworkwithouttheminalmostallcases.

❑SupportforpropertiesandeventsinthestyleofVisualBasic.

❑Justbychangingthecompileroptions,youcancompileeit