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IntroductionofMFCVisualC++ismuchmorethanacompiler.Itisacompleteapplicationdevelopmentenvironmentthat,whenusedasintended,letsyoufullyexploittheobjectorientednatureofC++tocreateprofessionalWindowsapplications.Inordertotakeadvantageofthesefeatures,youneedtounderstandtheC++programminglanguage.IfyouhaveneverusedC++,pleaseturntotheC++tutorialsintheC/C++Tutorialspageforanintroduction.YoumustthenunderstandtheFoundationClass(MFC)hierarchy.ThisclasshierarchyencapsulatestheuserinterfaceportionoftheWindowsAPI,andmakesitsignificantlyeasiertocreateWindowsapplicationsinanobjectorientedway.ThishierarchyisavailableforandcompatiblewithallversionsofWindows.ThecodeyoucreateinMFCisextremelyportable.ThesetutorialsintroducethefundamentalconceptsandvocabularybehindMFCandeventdrivenprogramming.Inthistutorialyouwillenter,compile,andrunasimpleMFCprogramusingVisualC++.2providesadetailedexnationofthecodeusedinTutorial1.Tutorial3discussesMFCcontrolsandtheircustomization.Tutorial4coversmessagemaps,whichletyouhandleeventsinMFC.WhatistheFoundationsClassLet'ssayyouwanttocreateaWindowsapplication.Youmight,forexample,needtocreateaspecializedtextordrawingeditor,oraprogramthatfindsfilesonalargeharddisk,oranapplicationthatletsauservisualizetheinterrelationshipsinabigdataset.Wheredoyoubegin?Agoodstartingceisthedesignoftheuserinterface.First,decidewhattheusershouldbeabletodowiththeprogramandthenpickasetofuserinterfaceobjectsaccordingly.TheWindowsuserinterfacehasanumberofstandardcontrols,suchasbuttons,s,scrollbars,andliststhatarealreadyfamiliartoWindowsusers.Withthisinmind,theprogrammermustchooseasetofcontrolsanddecidehowtheyshouldbearrangedonscreen.Atime-honoredprocedureistomakearoughsketchoftheproposeduserinterface(bytraditiononanapkinorthebackofanenvelope)andywiththeelementsuntiltheyfeelright.Forsmallprojects,orfortheearlyprototyphaseofalargerproject,thisissufficient.alsoprovidesaC++librarythatsitsontopofanyoftheWindowsAPIsandmakestheprogrammer'sjobeasier.CalledtheFoundationClasslibrary(MFC),thislibrary'sprimaryadvantageisefficiency.ItgreatlyreducestheamountofcodethatmustbewrittentocreateaWindowsprogram.ItalsoprovidesalltheadvantagesnormallyfoundinC++programming,suchasinheritanceandencapsulation.MFCisportable,sothat,forexample,codecreatedunderWindows3.1canmovetoWindowsNTor95veryeasily.MFCisthereforethepreferredmethodfordeveloWindowsapplicationsandwillbeusedthroughoutthesetutorials.WhenyouuseMFC,youwritecodethatcreatesthenecessaryuserinterfacecontrolsandcustomizestheirappearance.Youalsowritecodethatrespondswhentheusermanipulatesthesecontrols.Forexample,iftheuserclicksabutton,youwanttohavecodeincethatrespondsappropriay.Itisthissortofevent-handlingcodethatwillformthebulkofanyapplication.Oncetheapplicationrespondscorrectlytoalloftheavailablecontrols,itisfinished.YoucanseefromthisdiscussionthatthecreationofaWindowsprogramisastraightforwardprocesswhenusingMFC.Thegoalofthesetutorialsistofillinthedetailsandtoshowthetechniquesyoucanusetocreateprofessionalapplicationsasquicklyaspossible.TheVisualC++applicationdevelopmentenvironmentisspecificallytunedtoMFC,sobylearningMFCandVisualC++togetheryoucansignificantlyincreaseyourpowerasanapplicationdeveloper.ThevocabularyusedtotalkaboutuserinterfacefeaturesandsoftwaredevelopmentinWindowsisbasicbutunique.Herewereviewafewdefinitionstomakediscussioneasierforthosewhoarenewtotheenvironment.liveinsidea"framewindow".Aframewindowisafullyfeaturedmainwindowthattheusercanre-size,minimize,izetofillthescreen,andsoon.Windowsalsosupportstwotypesofdialogboxes:modalandmodeless.Amodaldialogbox,onceonthescreen,blocksinputtotherestoftheapplicationuntilitisanswered.Amodelessdialogboxcanappearatthesametimeastheapplicationandseemsto"floatabove"ittokeepfrombeingoverlaid.MostsimpleWindowsapplicationsuseaSingle Interface,orSDI,frame.TheClock,PIFeditor,andNotepadareexamplesofSDIapplications.WindowsalsoprovidesanorganizingschemecalledtheMultiple Interface,orMDIformorecomplicatedapplications.TheMDIsystemallowstheusertoviewmultiplesatthesametimewithinasingleinstanceofanapplication.Forexample,atexteditormightallowtheusertoopenmultiplefilessimultaneously.WhenimplementedwithMDI,theapplicationpresentsalargeapplicationwindowthatcanholdmultiplesub-windows,eachcontaininga.Thesinglemain isheldbythemainapplicationwindowanditappliestothetop-mostwindowheldwithintheMDIframe.IndividualwindowscanbeiconifiedorexpandedasdesiredwithintheMDIframe,ortheentireMDIframecanbeminimizedintoasingleicononthedesktop.TheMDIinterfacegivestheimpressionofaseconddesktopoutonthedesktop,anditgoesalongwaytowardsorganizingandremovingwindowclutter.Eachapplicationthatyoucreatewilluseitsownuniquesetofcontrols,itsownstructure,anditsowndialogboxes.Agreatdealoftheeffortthatgoescreatinganygoodapplicationinterfaceliesinthechoiceandorganizationoftheseinterfaceobjects.VisualC++,alongwithitsresourceeditors,makesthecreationandcustomizationoftheseinterfaceobjectsextremelyeasy.Event-drivenSoftwareandVocabularyAllwindow-basedGUIscontainthesamebasicelementsandalloperateinthesameway.Onscreentheuserseesagroupofwindows,eachofwhichcontainscontrols,icons,objectsandsuchthataremanipulatedwiththemouseorthekeyboard.Theinterfaceobjectsseenbytheuserarethesamefromsystemtosystem:pushbuttons,scrollbars,icons,dialogboxes,pulldowns,etc.Theseinterfaceobjectsallworkthesameway,althoughsomehaveminordifferencesintheir"lookandfeel."Forexample,scrollbarslookslightlydifferentasyoumovefromWindowstotheMactoMotif,buttheyalldothesamething.Fromaprogrammer'sstandpoint,thesystemsareallsimilarinconcept,althoughtheydifferradicallyintheirspecifics.TocreateaGUIprogram,theprogrammerfirstputsalloftheneededuserinterfacecontrolsintoawindow.Forexample,iftheprogrammeristryingtocreateasimpleprogramsuchasaFahrenheittoCelsiusconverter,thentheprogrammerselectsuserinterfaceobjectsappropriatetothetaskanddisysthemonscreen.Inthisexample,theprogrammermightlettheuserenteratemperatureinaneditabletextarea,disytheconvertedtemperatureinanotherun-editabletextarea,andlettheuserexittheprogrambyclickingonapush-buttonlabeledAstheusermanipulatestheapplication'scontrols,theprogrammustrespondappropriay.Theresponsesaredeterminedbytheuser'sactionsonthedifferentcontrolsusingthemouseandthekeyboard.Eachuserinterfaceobjectonthescreenwillrespondtoeventsdifferently.Forexample,iftheuserclickstheQuitbutton,thebuttonmustupdatethescreenappropriay,highlightingitselfasnecessary.Thentheprogrammustrespondbyquitting.Normallythebuttonmanagesitsappearanceitself,andtheprograminsomewayreceivesamessagefromthebuttonthatsays,"Thequitbuttonwaspressed.Dosomethingaboutit."Theprogramrespondsbyexiting.Windowsfollowsthissamegeneralpattern.Inatypicalapplicationyouwillcreateamainwindowandceinsideitdifferentuserinterfacecontrols.Thesecontrolsareoftenreferredtoaschildwindows-eachcontrolislikeasmallerandmorespecializedsub-windowinsidethemainapplicationwindow.Astheapplicationprogrammer,youmanipulatethecontrolsbysendingmessagesviafunctioncalls,andtheyrespondtouseractionsbysendingmessagesbacktoyourcode.Ifyouhaveneverdoneany"event-driven"programming,thenallofthismayforeigntoyou.However,theevent-drivenstyleofprogrammingiseasytounderstand.Theexactdetailsdependonthesystemandthelevelatwhichyouareinterfacingwithit,butthebasicconceptsaresimilar.Inanevent-driveninterface,theapplicationpaintsseveral(ormany)userinterfaceobjectssuchasbuttons,textareas,andsontothescreen.Nowtheapplicationwaits-typicallyinapieceofcodecalledaneventloop-fortheusertodosomething.Theusercandoanythingtoanyoftheobjectsonscreenusingeitherthemouseorthekeyboard.Theusermightclickoneofthebuttons,forexample.Themouseclickiscalledanevent.Eventdrivensystemsdefineeventsforuseractionssuchasmouseclicksandkeystrokes,aswellasforsystemactivitiessuchasscreenAtthelowestlevelof ion,youhavetorespondtoeacheventinafairamountofdetail.ThisisthecasewhenyouarewritingnormalCcodedirectlytotheAPI.Insuchascenario,youreceivethemouse-clickeventinsomesortofstructure.Codeinyoureventlooplooksatdifferentfieldsinthestructure,determineswhichuserinterfaceobjectwasaffected,perhapshighlightstheobjectinsomewaytogivetheuservisualfeedback,andthenperformstheappropriateactionforthatobjectandevent.Whentherearemanyobjectsonthescreentheapplication esverylarge.Itcantakequiteabitofcodesimplytofigureoutwhichobjectwasclickedandwhattodoaboutit.Fortunay,youcanworkatamuchhigherlevelof ion.InMFC,almostalltheselow-levelimplementationdetailsarehandledforyou.Ifyouwanttoceauserinterfaceobjectonthescreen,youcreateitwithtwolinesofcode.Iftheuserclicksonabutton,thebuttondoeseverythingneededtoupdateitsappearanceonthescreenandthencallsapre-arrangedfunctioninyourprogram.Thisfunctioncontainsthecodethatimplementstheappropriateactionforthebutton.MFChandlesallthedetailsforyou:Youcreatethebuttonandlitaboutaspecifichandlerfunction,anditcallsyourfunctionwhentheuserpressesit.Tutorial4showsyouhowtohandleeventsusingmessagemaps.Thestepsnecessarytoenterandcompilethisprogramarestraightforward.IfyouhavenotyetinstalledVisualC++onyourmachine,dosonow.Youwillhavetheoptionofcreatingstandardandcustominstallations.Forthepurposesofthesetutorialsastandardinstallationissuitableandafteransweringtwoorthreesimplequestionstherestoftheinstallationisquickandpainless.MFC简要介VisualC++C++Windows应用程序。为了能充分利用这些特性，你必须理解C++C++，你就必须掌握基本类库(MFC)的层次结构。该层次结构包容了WindowsAPI中的用户界面部分，并使你能够很容易地以面向对象的方式建立WindowsWindows用MFC所建立的代码是完全可移植的。这篇文章将向你介绍MFC的基本概念和术语以及驱动程序设计方法。MFC程序。下