Developing Web Applications with Visual Basic NET and ASP NET 编程语言讲义（英文版）.pdf

Dev eloping Web Applications with Visual Basic.NET and ASP.NETJo hn Alexander Billy Ho llisWiley Co mputer Publishing Jo hn Wiley&So ns,Inc.Publish er:Ro ber t IpsenEditor:Ther esa Hudso nDev elopmental Editor:Kathr yn A.MalmManaging Editor:Angela SmithNew Media Editor:Br ian SnappText Design&Composition:Jo hn Wiley Co mpo sitio n Ser v icesDesignatio ns used by co mpanies to distinguish their pr o ducts ar e o ften claimed as tr ademar k s.In all instances wher e Jo hn Wiley&So ns,Inc.,is awar e o f a claim,the pr o duct names appear in initial capital o r ALL CAPITAL LETTERS.Reader s,ho wev er,sho uld co ntact the appr o pr iate co mpanies fo r mo r e co mplete info r matio n r egar ding tr ademar k s and r egistr atio n.This bo o k is pr inted o n acid-fr ee paper.Co pyr ight 2002 by Jo hn Alexander and Billy Ho llis.All r ights r eser v ed.Publish ed by Joh n Wiley&Sons,Inc.,New YorkPublished simultaneo usly in Canada.No par t o f this publicatio n may be r epr o duced,sto r ed in a r etr iev al system o r tr ansmitted in any fo r m o r by any means,electr o nic,mechanical,pho to co pying,r eco r ding,scanning o r o ther wise,except as per mitted under Sectio ns 107 o r 108 o f the 1976 United States Co pyr ight Act,witho ut either the pr io r wr itten per missio n o f the Publisher,o r autho r izatio n thr o ugh payment o f the appr o pr iate per-co py fee to the Co pyr ight Clear ance Center,222 Ro sewo o d Dr iv e,Danv er s,MA 01923,[phone],fax[phone].Requests to the Publisher fo r per missio n sho uld be addr essed to the Per missio ns Depar tment,Jo hn Wiley&So ns,Inc.,605 Thir d Av enue,New Yo r k,NY 10158-0012,[phone],fax[phone],E-Mail:PERMREQWILEY.COM.This publicatio n is designed to pr o v ide accur ate and autho r itativ e info r matio n in r egar d to the subject matter co v er ed.It is so ld with the under standing that the publisher is no t engaged in pr o fessio nal ser v ices.If pr o fessio nal adv ice o r o ther exper t assistance is r equir ed,the ser v ices o f a co mpetent pr o fessio nal per so n sho uld be so ught.Library of Congress Cataloging-in-Publication Data:ISBN:0-471-08517-0Pr inted in the United States o f Amer ica.10 9 8 7 6 5 4 3 2 1To all our loved ones,those whom we hold so dear,and to those departed whom we miss.This is for you.Life is a measured gift,use it wisely and make it count.About th e Auth orsJoh n Alexander is the Mar k eting Techno lo gist fo r G.A.Sulliv an.His br o ad pr o ject exper ience includes building so lutio ns in sev er al industr ies o n platfo r ms r anging fr o m the mainfr ame to the Inter net.A Micr o so ft Cer tified So lutio n Dev elo per and Tr ainer with 19 cer tificatio ns,Jo hn has also wr itten Micr o so ft Official Cur r iculum(so me o f the ear liest o n Activ e Ser v er Pages)and co nsults and teaches at sites fr o m Seattle to Mo sco w.Highly exper ienced in so ftwar e estimatio n,r equir ements gather ing and definitio n,cr eating pr o ject plans,defining deliv er ables,and wo r k ing o n all phases o f the so ftwar e dev elo pment life cycle,Jo hn pr ides himself o n achiev ing so lutio ns that exceed the clients expectatio ns.A featur ed speak er at co nfer ences such as VB Co nnectio ns,Web Tech-Ed 98,Dev elo per Days,and VBITS,Jo hn has been no minated and cho sen by Micr o so ft fo r the fo ur th str aight year as a Micr o so ft Dev elo per Netwo r k Regio nal Dir ecto r.He is cur r ently ser v ing o n the Micr o so ft v ir tual.NET Subject Matter Exper t Team fo r Dev Days 2001,has co nsulted as a technical adv iser o n.NET e-Business Architecture by G.A.Sulliv an,published by SAMS,and has r ecently finished a speak ing to ur o n.NET techno lo gies.He is cur r ently adv ising a majo r client o n their fir st.NET pr o ject.G.A.Sulliv an is a glo bal e-Business so lutio n co mpany.Since 1982,G.A.Sulliv an pr o fessio nals hav e co nsistently deliv er ed co mplex enter pr ise so lutio ns and pr o v ided str ategic co nsulting to specific v er tical industr ies.The co mpanys fo cus is to dr iv e maximum business r esults fr o m techno lo gy inv estments.G.A.Sulliv an is a leader in implementing techno lo gy and pr o v iding business v alue using Micr o so fts.NET platfo r m.As o ne o f Micr o so fts leading dev elo pment par tner s wo r ldwide,G.A.Sulliv an has pr o v en exper ience as do cumented in numer o us case studies.G.A.Sulliv ans exper tise is v alidated in their mo st r ecent technical bo o k titled.NETe-Business Architecture,which do cuments best pr actices lear ned building an enter pr ise-class applicatio n utilizing the Micr o so ft.NET platfo r m.Details ar e av ailable at www.gasTIX.net.G.A.Sulliv an was amo ng the fir st co mpanies in the wo r ld to beco me a Micr o so ft Go ld Cer tified Par tner fo r E-Co mmer ce So lutio ns.With 300 pr o fessio nals acr o ss six U.S.and two Eur o pean lo catio ns,G.A.Sulliv an co nsistently r ank s as o ne o f the fastest gr o wing techno lo gy co mpanies in the United States.Lear n mo r e abo ut G.A.Sulliv an by v isiting www.gasulliv an.co m.Billy Hollis has been dev elo ping so ftwar e fo r o v er twenty year s.He has wr itten fo r many technical publicatio ns,and is a fr equent speak er at co nfer ences,including Co mdex,Micr o so fts Pr o fessio nal Dev elo per s Co nfer ence(PDC),and the Visual Basic Insider s Technical Summit(VBITS).Billy is co-autho r o f the fir st bo o k ev er published o n Visual Basic.NET,VB.NET Programming on the Public Beta,and so le autho r o f the bo o k Visual Basic 6:Design,Specification,and Objects.Billy is MSDN Regio nal Dir ecto r o f Dev elo per Relatio ns in Nashv ille,Tennessee fo r Micr o so ft,and was named Regio nal Dir ecto r o f the year fbr 2001.He is cur r ently heav ily inv o lv ed in tr aining,co nsultatio n,and so ftwar e dev elo pment o n the Micr o so ft.NET platfo r mCole Francis is a Senio r Co nsultant fbr G.A.Sulliv an in Kansas City,MO.He plays many r o les as a co nsultant,including Business Analyst,So ftwar e Dev elo per,and Quality Assur ance.Co le is a Micr o so ft MCP,deliv er s o ccasio nal pr esentatio ns fo r G.A.Sulliv an,and has r ecently tak en par t in a Micr o so ft Case Study.Co le wo uld lik e to thank his wife,Tami,and his daughter,Kyr stin,fbr their o ngo ing dedicatio n and suppo r t.Co le wo uld also lik e to thank Jo hn Alexander fbr the o ppo r tunity to be a par t o f this bo o k.Brian Wendt is a co nsultant in Nashv ille,Tennessee.He has been wo r k ing in the IT industr y since 1983,pr ev io usly in UNIX env ir o nments,and has spent the last ten year s wo r k ing with Micr o so ft techno lo gies.He ho lds sev er al Micr o so ft cer tificatio ns including MCSD,MCDBA,and MCSE+Inter net.In additio n to.NET,his sk ills include C,C+,Micr o so ft SQL Ser v er,ASP,Visual Basic,and Jav aScr ipt.AcknowledgmentsFr o m Jo hn:Jo hn wo uld lik e to thank Valer ie,Nathaniel,and Ian fo r stick ing by him thr o ugh the mak ing o f this bo o k.Daddy pr o mises no t to lo ck himself in the basement any mo r e.Thank s to the co ntr ibuto r s o n the bo o k:Co le Fr ancis and Br ian Wendt fbr the abso lutely r o ck ing jo b yo u guys did o n this.Thank s to Do nis Mar shall fo r the adv ice,guidance,assistance,and per sistence thr o ugho ut this pr o cess.Thank s to the fo llo wing fo lk s at G.A.Sulliv an:Gr eg Sulliv an,Dav e Smith,Do n Benage,Dav id Bur gett,Matthew Baute,and Er ic Br o wn.Dedicatio n to quality is o ften giv en lip ser v ice,in the co nsulting industr y but r ar ely fo llo wed thr o ugh.Im pr o ud to be a par t o f this o r ganizatio n!Jo hn also thank s the fo llo wing fo lk s at Micr o so ft that gav e assistance,bo th dir ectly and indir ectly:Jennifer Ritzinger,Dav id Lazar,Ar i Bixho r n,Susan War r en,Dav e Mendlen,Mik e lem,Sco tt Guthr ie,Ilya Buk shteyn,Keith Ballinger,Chr is Feather sto ne,and last but no t least Stev e Lo ethen.And o f co ur se Jo hn wo uld lik e to thank the Wiley Publishing cr ew that made this into what is no w:Kathr yn Malm,dev elo pmental edito r extr ao r dinair e,Ter r i Hudso n,Ben Ryan,Jen Ber gman,and his publisher,Ro ber t Ipsen.And finally thank s to Mo m and Dad fo r the Co mmo do r e Vic-20 that star ted it all.Fr o m Billy:Thank s,as usual,to my family fo r being fo r giv ing eno ugh to allo w me the time to wr ite ano ther bo o k.Cindy,Ansel,and Dyso n hav e all been wo nder ful thr o ugho ut my wr iting car eer.Id also lik e to o ffer appr eciatio n to the fo lk s at Micr o so ft that hav e giv en me inv aluable assistance in the past few mo nths,including,but no t limited to,Mik e lem,Ar i Bixho m,and Jennifer Ritzinger.They exemplify the spir it o f their co mpany.IntroductionDeveloping Web Applications with Visual Basic.NET and ASP.NET was bo m o ut o f a desir e to enable exper ienced Visual Basic dev elo per s to extend their k no wledge and exper ience inv estment to the Web easily and seamlessly.The tho ught behind this title is that the dev elo per wo uldnt need to master sev er al techno lo gies fo r ASP.NET dev elo pment but co uld use the integr ated to o ls and pr actical techniques to be pr o ductiv e quick ly.Its also designed to be a co de-based,hands-o n intr o ductio n that will pr epar e,yo u,the r eader fo r mo r e fo cused titles.Wh o Sh ould Read Th is BookIf yo u ar e a Visual Basic pr o gr ammer who has significant exper ience with:Ev ent-dr iv en pr o gr amming(including wo r k ing with fo r ms and co ntr o ls)COM co mpo nent dev elo pment Data access using ADO Basic familiar ity with HTML,but little expo sur e to Web-r elated dev elo pment co nceptsthen yo u sho uld r ead this bo o k.This bo o k will help yo u to extend yo ur existing k no wledge inv estment to building Micr o so ft techno lo gy-centr ic Web Applicatio ns in.NET.Fo r the VB Dev elo per,lear ning ASP Web dev elo pment meant dealing with a v ar iant o f VB,a blur r ed line between co de and co ntent,co mpo nent deplo yment issues,and bulk y,inter pr eted so lutio ns that ar e so metimes less-than-elegant.In additio n,the par adigm shift r equir ed fo r Web dev elo pment meant r ethink ing tr aditio nal applicatio n design and ar chitectur e metho ds as well.ASP.NET is an exciting new platfo r m fo r dev elo ping,deplo ying,and r unning Web applicatio ns.It is a majo r enhancement o f ASP;so lv ing per fo r mance,scalability,and deplo yment challenges while str engthening the platfo r m thr o ugh its extensiv e co mpiled pr o gr amming language suppo r t and a simplified,mo r e po wer ful page mo del.The integr atio n o f Web dev elo pment featur es in Visual Basic.NET thr o ugh its suppo r t o f ASP.NET allo ws VB dev elo per s to mak e the tr ansitio n mo r e easily than ev er befo r e,witho ut the use o f separ ate to o ls o r techno lo gies.A majo r ASP.NET design go al was to cr eate a similar pr o gr amming mo del so that VB dev elo per s wo uld hav e a sho r ter lear ning cur v e in building Web applicatio ns,thus so lv ing many o f the afo r ementio ned pr o blems using ear lier techno lo gies.This fr ees the dev elo per to fo cus o n the new co ncepts intr o duced by Web dev elo pment witho ut the need to lear n multiple env ir o nments and to o ls in the pr o cess.How Th is Book Is OrganizedChapter 1 pr o v ides a basis fo r intr o ducing the v isio n o f the Next Gener atio n Web:Micr o so ft.NET!The dev elo per is intr o duced to the.NET co mmo n language r untime and extensiv e language suppo r t.Next,Micr o so ft.NET Enter pr ise Ser v er s(such as Co mmer ce Ser v er and BizTalk Ser v er)ar e br iefly discussed befo r e descending to highlight the nativ e under lying Inter net r elated ser v ices expo sed by Windo ws 2000.This discussio n culminates in Chapter 1 with an o v er v iew o f the pr o gr amming enhancements and fundamental changes to Web dev elo pment that ASP.NET pr o v ides.The po int o f this chapter is to star t a fo undatio n that will set the o v er all to ne fo r the r emainder o f the bo o k.Chapter 2 begins with issues and co ncepts sur r o unding the impr essiv e changes that especially impact ASP.NET dev elo pment.Expanding the back gr o und in the pr ev io us chapter,no w we star t to explo r e the new featur es o f the next v er sio n o f Visual Basic.As the new env ir o nment featur es ar e highlighted,the r eader will under stand that the Visual Basics RAD v ir tues hav e been extended fo r Web dev elo pment.Building o n the changes intr o duced in Chapter 2,Chapter 3 co ntinues with tho se changes in Visual Basic that per tain to Object-o r iented dev elo pment.The fo cus o f Chapter 4 is to acquaint the Visual Basic dev elo per with DHTML fo r use in building ASP.NET Applicatio ns.Attentio n is giv en to illustr ate the impr o v ements br o ught abo ut by the new ser v er-side co ntr o ls and the expanded flexibility that dev elo per s gain.Impo r tant fo r all lev els o f br o wser suppo r t,the ability o f the ser v er-side co ntr o ls to auto matically gener ate uplev el and do wnlev el HTML intelligently is sho wn as well.Chapter 5 giv es an o v er v iew o f ASP.NET Pages,building o n the k no wledge o f the pr ev io us pr epar ato r y chapter s.As ASP.NET suppo r t is co mpletely integr ated into Visual Basic.NET,VB dev elo per s ar e able to effectiv ely use their exper ience in mak ing the tr ansitio n to web dev elo pment.Dev elo per s will also disco v er the ease o f UI dev elo pment thr o ugh the use o f WebFo r ms,the use o f the Co de-behind metho d o f wr iting ASP.NET Page co de,and the simplified page o bject mo del.VB dev elo per s who hav e exper ience with WebClasses will appr eciate the expanded capability and functio nality o f WebFo r ms illustr ated thr o ugh sev er al examples.One o f the exciting new featur es o f ASP.NET is the ability to utilize and custo mize ser v erside co ntr o ls.As co ntr o l usage is natur al to ev er y VB dev elo per,this k no wledge will be extended to ASP.NET.Building o n the discussio n in Chapter 4 with HTMLCo ntr o ls,the fo cus in Chapter 6 no w shifts to the WebCo ntr o ls,illustr ating usage and functio n thr o ugh pr actical examples.Since many o f the WebCo ntr o ls will be familiar to the VB Dev elo per fr o m the star t,the emphasis is o n essential usage scenar io s such as page nav igatio n,v alidatio n,data access,and client-ev ent handling to pics.In additio n,wev e added a br ief sectio n o n cr eating custo m co ntr o ls.Chapter 7 deals with the seco nd member o f the ASP.NET platfo r m:Web Ser v ices.Web Ser v ices can be used to enable r emo te access to inter nal systems fr o m the Inter net,ther eby suppo r ting integr atio n and business-to-business applicatio ns.Dev elo per s will lear n that Web Ser v ices ar e ser v er o bjects that use the Simple Object Access Pr o to co l(SOAP)(o r HTTP-Get/Po st)to accept r equests and r etur n r esults.They also disco v er that clients using the Ser v ice Descr iptio n Language(SDL)dis