visual programming.pdf

8/14/2019 Visual Programming.pdf

1/96

Advanced Visual and Windows Programming(BCA-205)

NAVGUA!A" C#$$%G%

#& C#'PU"%! APP$CA"#Nu*+ec,Advance visual and windows .rogramming(BCA-205)

u*+ec, Code BCA-205&acul,/Pro1aus3ar G3anc3i

Navgu+ara, BCA Page 4 o 6


2/96


The .NET Framework

The .NET Framework is the next iteration of Microsoft's platform fordeveloping component-based software. It provides fndamental advances inrntime services for application software. It also

spports development of applications that can be free of dependencies onhardware! operating s"stem! and langage compiler.This chapter provides an overview of the architectre of the .NET Framework

and describes the base featres fond in the core of its class librar".

Common Language Infrastructure (CLI) and Common LanguageRuntime (CLR)

At the heart of the .NET Framework is a new mechanism for loading and runningprograms and managing their interactions. This mechanism is described in the Common

Language Infrastructure (CLI! a specification for a runtime en"ironment that allowssoftware components to#

$$$$$$%ass data between each other without regard to the programming language in whicheach component is on paper

$$$$$$E&ecute on different operating s'stems and on different hardware platforms withoutha"ing to recompile the highle"el source code (a lowle"el compilation still automaticall'occurs on the target platform! as will be discussed in this chapter

Although the CLI specification was created b' )icrosoft! it has since been submitted tothe ECMA standards organi*ation (http#++www.ecma.ch! which now has responsibilit'and control o"er it.The CLI is ,ust a specification-it has to be implemented in order to be useful. An

implementation of the CLI is known as a Common Language Runtime (CL. )icrosoft/sCL implementation on the 0indows platform is not under EC)A/s control! but it is)icrosoft/s intention that the CL be a full' compliant implementation of the CLI. As ofthis writing! the CLI has not been implemented on non 0indows platforms! but )icrosoftand others ha"e announced intentions to do so.The CLI specifies how e&ecutable code is loaded! run! and managed. The portion of theCL that performs the tasks of loading! running! and managing .NET applications iscalled the virtual execution system (1E2. Code run b' the 1E2 is called managed code.The CLI greatl' e&pands upon concepts that e&ist in )icrosoft/s Component ObjectModel (C3). As its core feature! C3) specifies how ob,ect interfaces are laid out inmemor'. An' component that can create and consume this la'out can share data with

other components that do the same. C3) was a big step forward when it wasintroduced (circa 4556! but it has its shortcomings.

Common Type System (CTS)

The CLI specification defines a rich t'pe s'stem that far surpasses C3)/s capabilities. It/s calledthe Common Type ystem (CT2. The CT2 defines at the runtime le"el how t'pes are declaredand used.



3/96


4/96


compiled! subse=uent calls b'pass the compilation mechanism and call the compiled codedirectl'. The compiled code is not sa"ed to disk! so if the application is stopped and restarted! thecompilation must occur again. This is known as just!in!time (9IT compilation and is the mostcommon scenario.In the second case! the application is compiled in its entiret' at deplo'ment time. IL is sa"edto .exe and .dll files. 0hen such a file containing IL is e&ecuted! the CL knows how to in"oke the9IT compiler and e&ecute the resulting code. Note that on the )icrosoft 0indows platforms! IL isalwa's compiled-ne"er interpreted.

Metadata2ource code consists of some constructs that are procedural in nature and others that aredeclarative in nature. An e&ample of a procedural construct is#someObject.SomeMember = 5

This is procedural because it compiles into e&ecutable code that performs an action at runtime.Namel'! it assigns the "alue 5 to the 2ome)ember member of the some3b,ect ob,ect.

In contrast! here is a declarati"e construct#Dim someObject As SomeClass

This is declarati"e because it doesn/t perform an action. It states that the s'mbol some3b,ect is a"ariable that holds a reference to an ob,ect of t'pe 2omeClass.

In the past! declarati"e information t'picall' was used onl' b' the compiler and did not compiledirectl' into the e&ecutable. In the CL! howe"er! declarati"e information is e"er'thing> The CLuses t'pe and signature information to ensure that memor' is alwa's referenced in a safe wa'.The 9IT compiler uses t'pe and signature information to resol"e method calls to the appropriatetarget code at 9IT compile time. The onl' wa' for this to work is for this declarati"e information tobe included alongside its associated procedural information. Compilers that target the CLtherefore store both procedural and declarati"e information in the resulting .exe or .dll file. Theprocedural information is stored as IL! and the declarati"e information is stored as metadata.)etadata is ,ust the CLI/s name for declarati"e information.

Modules and Assemblies

A module is an "exe or "dll file. An assembly is a set of one or more modules that together make

up an application. If the application is full' contained in an "exe file! fine-that/s a onemoduleassembl'. If the "exe is alwa's deplo'ed with two "dll files and one thinks of all three files ascomprising an inseparable unit! then the three modules together form an assembl'! but none ofthem does so b' itself. If the product is a class librar' that e&ists in a "dll file! then that single "dllfile is an assembl'. To put it in )icrosoft/s terms! the assembl' is the unit of deplo'ment in .NET.

An assembl' is more than ,ust an abstract wa' to think about sets of modules. 0hen anassembl' is deplo'ed! one (and onl' one of the modules in the assembl' must contain theassembly manifest! which contains information about the assembl' as a whole! including the listof modules contained in the assembl'! the "ersion of the assembl'! its culture! etc.

Memory Management and arbage CollectionIn an' ob,ectoriented programming en"ironment! there arises the need to instantiate and destro'ob,ects. Instantiated ob,ects occup' memor'. 0hen ob,ects are no longer in use! the memor'

the' occup' should be reclaimed for use b' other ob,ects. ecogni*ing when ob,ects are nolonger being used is called lifetime management! which is not a tri"ial problem. The solution theCL uses has implications for the design and use of the components 'ou write! so it is worthunderstanding.In the C3) world! the client of an ob,ect notified the ob,ect whene"er a new ob,ect reference waspassed to another client. Con"ersel'! when an' client of an ob,ect was finished with it! the clientnotified the ob,ect of that fact. The ob,ect kept track of how man' clients had references to it.0hen that count dropped to *ero! the ob,ect was free to delete itself (that is! gi"e its memor' backto the memor' heap. This method of lifetime management is known as reference counting.1isual 7asic programmers were not necessaril' aware of this mechanism because the 1isual



5/96


7asic compiler automaticall' generated the lowle"el code to perform this housekeeping. C::de"elopers had no such lu&ur'.eference counting has some drawbacks#

A method call is re=uired e"er' time an ob,ect reference is copied from one "ariable to anotherand e"er' time an ob,ect reference is o"erwritten.

;ifficulttotrack bugs can be introduced if the referencecounting rules are not precisel'

followed. Care must be taken to ensure that circular references are speciall' treated (because circularreferences can result in ob,ects that ne"er go awa'.The CL mechanism for lifetime management is =uite different. eference counting is not used.Instead! the memor' manager keeps a pointer to the address at which free memor' (known asthe #eap starts. To satisf' a memor' re=uest! it ,ust hands back a cop' of the pointer and thenincrements the pointer b' the si*e of the re=uest! lea"ing it in a position to satisf' the ne&tmemor' re=uest. This makes memor' allocation "er' fast. No action is taken at all when anob,ect is no longer being used. As long as the heap doesn/t run out! memor' is not reclaimed untilthe application e&its. If the heap is large enough to satisf' all memor' re=uests during programe&ecution! this method of memor' allocation is as fast as is theoreticall' possible! because theonl' o"erhead is incrementing the heap pointer on memor' allocations.If the heap runs out of memor'! there is more work to do. To satisf' a memor' re=uest when theheap is e&hausted! the memor' manager looks for an' pre"iousl' allocated memor' that can bereclaimed. It does this b' e&amining the application "ariables that hold ob,ect references. Theob,ects that these "ariables reference (and therefore the associated memor' are considered inuse because the' can be reached through the program/s "ariables. Furthermore! because theruntime has complete access to the application/s t'pe information! the memor' manager knowswhether the ob,ects contain members that reference other ob,ects! and so on. In this wa'! thememor' manager can find all of the memor' that is in use. ;uring this process! it consolidates thecontents of all this memor' into one contiguous block at the start of the heap! lea"ing theremainder of the heap free to satisf' new memor' re=uests.This process of freeing up memor' is known as garbage collection (?C! a term that also appliesto this o"erall method of lifetime management. The portion of the memor' manager that performsgarbage collection is called the garbage collector.The benefits of garbage collection are#

No o"erhead is incurred unless the heap becomes e&hausted.

It is impossible for applications to cause memor' leaks.

The application need not be careful with circular references.Although the process of garbage collection is e&pensi"e (on the order of a fraction of a secondwhen it occurs! )icrosoft claims that the total o"erhead of garbage collection is on a"erage muchless than the total o"erhead of reference counting (as shown b' their benchmarks. This! ofcourse! is highl' dependent on the e&act pattern of ob,ect allocation and deallocation that occursin an' gi"en program.

.NET Defined

Beore ge,,ing dee.l/ in,o ,3e su*+ec, we will irs, 9now 3ow Businesses are rela,ed ,o

n,erne,: w3a, 1N%" means ,o ,3em and w3a, e;ac,l/ 1N%" is *uil, u.on1 As .er ,3e.roduc, documen,a,ion rom a Business .ers.ec,ive: ,3ere are ,3ree .3ases o ,3e

n,erne,1 "3e &irs, .3ase ge,s *ac9 ,o ,3e earl/ 40


6/96


eec,ivel/ communica,e wi,3 ,3eir cus,omers and .ar,ners w3o are geogra.3icall/

isola,ed: .ar,ici.a,e in =igi,al %conom/ and deliver a wide range o services1 >ow can

,3a, *e .ossi*le? "3e answer: wi,3 1N%"1

What is .NET ?

'an/ .eo.le rec9on ,3a, i,


7/96


T!PES OF FI"ES #ND T$EI% E&TENSIONS 1uo olu,ion User #.,ion &ile

1V* An/ &ile &rom &ollowing

A Basic Window &orm

A Code &ile

A 'odule &ile &or ,oring &unc,ions

A User Con,rol

As =a,a &orm

A Cus,om Con,rol

An n3eri,ed &orm

A We* Cus,om Con,rol

An n3eri,ed User Con,rol

A Window ervices

An Assem*l/ no &ile 1@sd An @ml c3ema Provided "o Crea,e =a,ase,s

1>,m An >,ml =ocumen,

1";, A "e;, &ile

1!., Cr/s,al !e.or,

1Bm. Bi,ma. &ile

1s scri., &ile

1V*s V*scri., &ile 1Ws Windows cri.,ing &ile

1As.; A We* &orm

1As. An Ac,ive erver Page

1Asm; We* ervice Class

1Vsdisco A =/namic =iscover/ Pro+ec,

1We* A We Conigura,ion &ile

1Asa; A Glo*al A..lica,ion Class

1!e; A !esource &ile "o ,ore !esource norma,ion

1ln olu,ion &ile

1V*.ro+ V* Pro+ec, &ile

1V*.ro+1User V* Pro+ec, User #.,ion &ile

VB .NET IDE

,ar, Page 'enu Bar

"ool*ars

New Pro+ec, =ilog*o;

#*+ec, Browser

"3e "ool*o;

"3e olu,ion %;.lorer

Navgu+ara, BCA Page o 6


8/96


Class View Window

Pro.er,/ Window

=/namic >el. Window

Com.onen, "ra/

"3e erver %;.lorer

"3e #u,.u, Window

"3e "as9 $is,

"3e Command Window

Gra.3ical =esigners

&orm =esigners

We* &orm =esigners

Com.onen, =esigner

@ml =esigneres

Code =esigners

'ODES OF VB .NET

=esign "ime 'ode

!un,ime 'ode

Brea9 "ime 'ode

VB "an()a(e

Visual Basic: ,3e name ma9es me eel ,3a, i, is some,3ing s.ecial1 n ,3e >is,or/ oCom.u,ing world no o,3er .roduc, sold more co.ies ,3an Visual Basic did1 uc3 is ,3e

im.or,ance o ,3a, language w3ic3 clearl/ s,a,es 3ow widel/ i, is used or develo.ing

a..lica,ions1 Visual Basic is ver/ .o.ular or i,


9/96


/s,em1 Collec,ions ncludes classes and in,eraces ,3a, deine various collec,ion

o o*+ec,s suc3 as lis,: ueues:

3as3 ,a*les: arra/s: e,c /s,em1 =a,a ncludes classes w3ic3 le,s us 3andle da,a rom da,a sources

/s,em1=a,a1#le=* ncludes classes ,3a, su..or, ,3e #$%=B 1N%" .rovider

/s,em1 =rawing Provides access ,o drawing me,3ods

/s,em1# ncludes classes or da,a access wi,3 &iles

/s,em1 "3reading ncludes classes and in,eraces ,o su..or, mul,i,3readed

/s,em1 We* ncludes classes and in,eraces ,3a, su..or, *rowser-server

/s,em1Windows1&orms ncludes classes or crea,ing Windows *ased orms

#sse*b+ies

An assem*l/ is ,3e *uilding *loc9 o a 1N%" a..lica,ion1 , is a sel descri*ing collec,iono code: resources: and me,ada,a (da,a a*ou, da,a: e;am.le: name: siDe: version o a ile

is me,ada,a a*ou, ,3a, ile)1 An Assem*l/ is a com.lied and versioned collec,ion o codeand me,ada,a ,3a, orms an a,omic unc,ional uni,1 Assem*lies ,a9e ,3e orm o a

d/namic lin9 li*rar/ (1dll) ile or e;ecu,a*le .rogram ile (1e;e) *u, ,3e/ dier as ,3e/

con,ain ,3e inorma,ion ound in a ,/.e li*rar/ and ,3e inorma,ion a*ou, ever/,3ing elseneeded ,o use an a..lica,ion or com.onen,1 All 1N%" .rograms are cons,ruc,ed rom

,3ese Assem*lies1 Assem*lies are made o ,wo .ar,s manies,: con,ains inorma,ion

a*ou, w3a, is con,ained wi,3in ,3e assem*l/ and modules: in,ernal iles o $ code w3ic3are read/ ,o run1 W3en .rogramming: we don


10/96


Access s.eciiers le,


11/96


W3en ,/.es canno, *e im.lici,l/ conver,ed /ou s3ould conver, ,3em e;.lici,l/1 "3is

conversion is also called as cas,1 %;.lici, conversions are accom.lis3ed using C"/.e

unc,ion1C"/.e unc,ion or conversion

we are no, sure o ,3e name o a .ar,icular conversion unc,ion ,3en we can use ,3e

C"/.e unc,ion1 "3e a*ove e;am.le wi,3 a C"/.e unc,ion loo9s li9e ,3ism.or,s /s,em1Console

'odule 'odule4

u* 'ain()=im d As =ou*le

d F 472174227

=im i As n,eger

i F C"/.e(d: i)


12/96


K 'ul,i.lica,ion

L =ivision

M n,eger =ivision'od 'odulus Ari,3me,ic

I Addi,ion

- u*,rac,ion

Conca,ena,ion #.era,orsConca,ena,ion o.era,ors +oin mul,i.le s,rings in,o a single s,ring1 "3ere are ,wo

conca,ena,ion o.era,ors: I and H as summariDed *elow

#.era,or Use

I ,ring Conca,ena,ionH ,ring Conca,ena,ion

Com.arison #.era,ors

A com.arison o.era,or com.ares o.erands and re,urns a logical value *ased on w3e,3er,3e com.arison is ,rue or no,1 "3e ,a*le *elow summariDes ,3em

#.era,or UseF %uali,/

O neuali,/

$ess ,3anO Grea,er ,3an

OF Grea,er ,3an or eual ,o

F $ess ,3an or eual ,o

$ogical L Bi,wise #.era,ors

"3e logical o.era,ors com.are Boolean e;.ressions and re,urn a Boolean resul,1 n s3or,:

logical o.era,ors are e;.ressions w3ic3 re,urn a ,rue or alse resul, over a condi,ionale;.ression1 "3e ,a*le *elow summariDes ,3em

#.era,or Use

No, Nega,ion

And Con+unc,ion

AndAlso Con+unc,ion

#r =is+unc,ion

#r%lse =is+unc,ion

@or =is+unc,ion

#rraysArra/s are .rogramming cons,ruc,s ,3a, s,ore da,a and allow us ,o access ,3em */numeric inde; or su*scri.,1 Arra/s 3el.s us crea,e s3or,er and sim.ler code in man/

si,ua,ions1 Arra/s in Visual Basic 1N%" in3eri, rom ,3e Arra/ class in ,3e /s,emnames.ace1 All arra/s in VB as Dero *ased: meaning: ,3e inde; o ,3e irs, elemen, is Dero

and ,3e/ are num*ered seuen,iall/1 Eou mus, s.eci/ ,3e num*er o arra/ elemen,s */

indica,ing ,3e u..er *ound o ,3e arra/1 "3e u..er *ound is ,3e numder ,3a, s.eciies ,3e

inde; o ,3e las, elemen, o ,3e arra/1 Arra/s are declared using =im: !e=im: ,a,ic:



13/96


Priva,e: Pu*lic and Pro,ec,ed 9e/words1 An arra/ can 3ave one dimension (liinear arra/s)

or more ,3an one (mul,idimensional arra/s)1 "3e dimensionali,/ o an arra/ reers ,o ,3e

num*er o su*scri.,s used ,o iden,i/ an individual elemen,1 n Visual Basic we cans.eci/ u. ,o 72 dimensions1 Arra/s do no, 3ave i;ed siDe in Visual Basic1

"3e ollowing code demons,ra,es arra/s1

'odule 'odule4u* 'ain()

=im s.or,(5) As ,ring

oc9e/


14/96


Para*eters1

str Name o ,3e ,ring varia*le ,o modi/1

Start n,eger da,a ,/.e1 C3arac,er .osi,ion in ,arge, w3ere ,3e re.lacemen, o ,e;, *egins1,ar, uses a one *ased inde;1

Pu*lic &unc,ion Stro*p(B/Val String1As Strin(2 B/Val String2As Strin(2#.,ional B/Val CompareAs 'icrosoft.Vis)a+Basic.o*pare'ethod F 0) As Inte(er 'em*er o 'icrosoft.Vis)a+Basic 1Strin(s

S)**ary1

!e,urns -4: 0: or 4: *ased on ,3e resul, o a s,ring com.arison1 "3e s,rings are com.ared*/ al.3anumeric sor, values *egining wi,3 ,3e irs, c3arac,er1

Para*eters1

String1 An/ valid ,ring e;.ression1String2 An/ valid ,ring e;.ression1

Compare .eciies ,3e ,/.e o s,ring com.arison1 com.are is omi,,ed: ,3e #.,ionCom.are se,,ing de,ermines ,3e ,/.e o com.arison1

Pu*lic &unc,ion /ethar(B/ValstrAs Strin(2 B/ValIndexAs Inte(er) As

har

'em*er o 'icrosoft.Vis)a+Basic 1Strin(sS)**ary1

!e,urns ,3e c3arac,er a, a s.eciied .osi,ion in a s,ring

Para*eters1

str ,ring ,o use as a source

Index 4 *ased inde; o ,3e c3arac,er ,o re,urn Pu*lic &unc,ion InStr(B/Val StartAs Inte(er2 B/Val String1As Strin(2 B/Val

String2As Strin(2 #.,ional B/Val CompareAs

'icrosoft.Vis)a+Basic.o*pare'ethod F 0) As Inte(er 'em*er o 'icrosoft.Vis)a+Basic 1Strin(s

S)**ary1

!e,urns an n,eger s.eci/ing ,3e s,ar, .osi,ion o ,3e irs, occurrence o one s,ring wi,3in

ano,3er1

Para*eters1

Start Numeric e;.ression ,3a, se,s ,3e s,ar,ing .osi,ion or eac3 searc31 omi,,ed:

searc3 *egins a, ,3e irs, c3arac,er .osi,ion1 "3e s,ar, inde; is 4 *ased1String1 ,ring e;.ression *eing searc3ed1

String2 ,ring e;.ression soug3,1

Pu*lic &unc,ion InStr%ev(B/Val StringCheckAs Strin(2 B/Val StringMatchAs

Strin(2 #.,ional B/Val StartAs Inte(erF -42 #.,ional B/Val CompareAs

'icrosoft.Vis)a+Basic.o*pare'ethod F 0) As Inte(er

'em*er o 'icrosoft.Vis)a+Basic 1Strin(s



15/96


S)**ary1

!e,urns ,3e .osi,ion o ,3e irs, occurrence o one s,ring wi,3in ano,3er: s,ar,ing rom ,3e

rig3, side o ,3e s,ring1

Para*eters1

StringCheck ,ring e;.ression *eing searc3ed1

StringMatch ,ring e;.ression *eing searc3ed or1Start Numeric e;.ression ,3a, se,s ,3e one-*ased s,ar,ing .osi,ion or eac3 searc3:

s,ar,ing rom ,3e le, side o ,3e s,ring1 ,ar, is omi,,ed: 4 is used: w3ic3 means ,3a,

,3e searc3 *egins a, ,3e las, c3arac,er .osi,ion1 earc3 ,3en .roceeds rom rig3, ,o le,1 Pu*lic &unc,ion 3oin(B/Val SourceArray() As Obect2 #.,ional B/ValDelimiter

As Strin(F ) As Strin( 'em*er o 'icrosoft.Vis)a+Basic 1Strin(s

S)**ary1

!e,urns a s,ring crea,ed */ +oining a num*er o su*s,rings con,ained in an arra/1

Para*eters1

SourceArray #ne-dimensional arra/ con,aining su*s,rings ,o *e +oined1

Delimiter ,ring used ,o se.ara,e ,3e su*s,rings in ,3e re,urned s,ring1 omi,,ed: ,3es.ace c3arac,er ( ) is used1 =elimi,er is a Dero-leng,3 s,ring (): all i,ems in ,3e lis,

are conca,ena,ed wi,3 no delimi,ers1

Pu*lic &unc,ion "ase(B/Val ValueAs Strin() As Strin( 'em*er o 'icrosoft.Vis)a+Basic 1Strin(s

S)**ary1

!e,urns a ,ring or C3ar ,3a, 3as *een conver,ed ,o lowercase1

Para*eters1

Value An/ valid ,ring or C3ar e;.ression1 Pu*lic &unc,ion "eft(B/ValstrAs Strin(2 B/ValLengthAs Inte(er) As Strin( 'em*er o 'icrosoft.Vis)a+Basic 1Strin(s

S)**ary1

!e,urns a ,ring con,aining a s.eciied num*er o c3arac,ers rom ,3e le, side o a s,ring1

Para*eters1

Str ,ring e;.ression rom w3ic3 ,3e le,mos, c3arac,ers are re,urned1Length n,eger e;.ression1 Numeric e;.ression indica,ing 3ow man/ c3arac,ers ,o

re,urn1 0: a Dero-leng,3 s,ring () is re,urned1 grea,er ,3an or eual ,o ,3e num*er o

c3arac,ers in ,r: ,3e en,ire s,ring is re,urned1

Pu*lic &unc,ion "en(B/ValExpressionAs Byte) As Inte(er 'em*er o 'icrosoft.Vis)a+Basic 1Strin(s S)**ary1

!e,urns an n,eger con,aining ei,3er ,3e num*er o c3arac,ers in a s,ring or ,3enum*er o */,es reuired ,o s,ore a varia*le1

Para*eters1

Expression valid ,ring e;.ression or varia*le name1 %;.ression is o ,/.e#*+ec,: ,3e $en unc,ion re,urns ,3e siDe as i, will *e wri,,en ,o ,3e ile1

Pu*lic &unc,ion 'id(B/ValstrAs Strin(2 B/Val StartAs Inte(er) As Strin( 'em*er o 'icrosoft.Vis)a+Basic 1Strin(s

S)**ary1



16/96


!e.laces a s.eciied num*er o c3arac,ers in a ,ring varia*le wi,3 c3arac,ers rom

ano,3er s,ring1

Para*eters1

str Name o ,3e ,ring varia*le ,o modi/1

Start n,eger da,a ,/.e1 C3arac,er .osi,ion in ,arge, w3ere ,3e re.lacemen, o ,e;, *egins1

,ar, uses a one *ased inde;1

Pu*lic &unc,ion %ep+ace(B/ValExpressionAs Strin(2 B/ValindAs Strin(2B/Val!eplacementAs Strin(2 #.,ional B/Val StartAs Inte(erF 42 #.,ional B/ValCountAs Inte(erF -42 #.,ional B/Val CompareAs

'icrosoft.Vis)a+Basic.o*pare'ethod F 0) As Strin( 'em*er o 'icrosoft.Vis)a+Basic 1Strin(s

S)**ary1

!e,urns a s,ring in w3ic3 a s.eciied su*s,ring 3as *een re.laced wi,3 ano,3er su*s,ring a

s.eciied num*er o ,imes1

Para*eters1

Expression ,ring e;.ression con,aining su*s,ring ,o re.lace1ind u*s,ring *eing searc3ed or1

!eplacement !e.lacemen, su*s,ring1Start Posi,ion wi,3in %;.ression w3ere su*s,ring searc3 is ,o *egin1 omi,,ed: 4 is

assumed1

Count Num*er o su*s,ring su*s,i,u,ions ,o .erorm1 omi,,ed: ,3e deaul, value is 4:w3ic3 means ma9e all .ossi*le su*s,i,u,ions1

Compare Numeric value indica,ing ,3e 9ind o com.arison ,o use w3en evalua,ing

su*s,rings1 ee e,,ings or values1

Pu*lic &unc,ion Sp+it(B/ValExpressionAs Strin(2 #.,ional B/ValDelimiterAs

Strin(F 2 #.,ional B/ValLimitAs Inte(erF -42 #.,ional B/Val CompareAs

'icrosoft.Vis)a+Basic.o*pare'ethod F 0) As Strin(() 'em*er o 'icrosoft.Vis)a+Basic 1Strin(s

S)**ary1

!e,urns a Dero-*ased: one-dimensional arra/ con,aining a s.eciied num*er o su*s,rings1

Para*eters1

Expression ,ring e;.ression con,aining su*s,rings and delimi,ers1 %;.ression is a

Dero-leng,3 s,ring (): ,3e .li, unc,ion re,urns an arra/ wi,3 no elemen,s and no da,a1

Delimiter ingle c3arac,er used ,o iden,i/ su*s,ring limi,s1 =elimi,er is omi,,ed: ,3es.ace c3arac,er ( ) is assumed ,o *e ,3e delimi,er1 =elimi,er is a Dero-leng,3 s,ring: a

single-elemen, arra/ con,aining ,3e en,ire %;.ression s,ring is re,urned1

Limit Num*er o su*s,rings ,o *e re,urnedQ ,3e deaul,: 4: indica,es ,3a, all su*s,ringsare re,urned1

Compare Numeric value indica,ing ,3e com.arison ,o use w3en evalua,ing su*s,rings1

ee e,,ings or values1

C#N"!#$ "A"%'%N" & condi,ion ">%N

%$%& condi,ion ">%N



17/96


%$%

%N= &

%$%C" CA% e;.r

CA% e;.rls,4

CA% e;.rls,2R1

R1

CA% e;.rls,N

%N= %$%C"

W"C>(e;.r-4:value-4:e;.r-2: value-2:11e;.r-N: value-N)

C>##%(inde;:c3ice-4: c3ice-2: c3ice-7R1 c3ice-N)$##PNG C#N"UC"

=# w3ileLun,il condi,ion

,m,

%;i, do $##P or inde;Fs,ar, ,o end s,e.

,a,emen,s

%;i, or

N%@"

W>$% condi,ion

,a,emen,sW%N=

W"> o*+ec,,a,emen,s

%N= W">

'essa(ebo- F)nction

'essa(eBo-.Sho45#r()*ents6

everal c3oices or argumen, lis, n,roduces conce., o #verloaded unc,ions

'ul,i.le signa,ures ,o c3oose rom

'essa(eBo-.Sho45TextMessage6

'essa(eBo-.Sho45TextMessage2 TitlebarText6

'essa(eBo-.Sho45TextMessage2 TitlebarText2 7

MessageBoxButtons6



18/96


'essa(eBo-.Sho45TextMessage2 TitlebarText2 7

MessageBoxButtons, MessageBoxIcon6

'essageBo; cons and *u,,ons

%numera,ion o cons,an,s

'en)s2S)b Proced)res2S)b F)nctions

Crea,ing 'enus and 'enu ,ems

Crea,ing Con,e;,'enus

=is.la/ing Common =ialog Bo;es

Wri,ing General Procedures

'enus

Crea,e a menu */ adding a 'ain'enu con,rol ,o ,3e com.onen, ,ra/

Grea, new 'enu =esigner re.laces ,3e 'enu %di,or

'enus

&or Con,e;, menus: add a Con,e;,'enu con,rol

A Con,e;,'enu uses ,3e same 'enu =esigner as a 'ain'enu

A,,ac3 a con,e;, menu */ se,,ing ,3e Con,e;,'enu .ro.er,/ o a con,rol or ,3e

orm

u* &unc,ion

Argumen,s are .assed B/Val (*/ deaul,) "3e %di,or adds B/Val i /ou leave i, ou,

New !e,urn s,a,emen, Can s,ill se, unc,ion name ,o value Be,,er ,o use ,3e !e,urn s,a,emen,

Private F)nction a+c)+ateS)*5 7

ByVa+ intN)*8 #s Inte(er2 7

ByVa+ intN)*9 #s Inte(er6 #s Inte(er

:a+c)+ate the s)* of the n)*bers

%et)rn intN)*8 ; intN)*9End F)nction

ONT%O"S

B)tton ontro+



19/96


#ne o ,3e mos, .o.ular con,rol in Visual Basic is ,3e Bu,,on Con,rol (.reviousl/Command Con,rol)1 "3e/ are ,3e con,rols w3ic3 we clic9 and release ,o .erorm some

ac,ion1 Bu,,ons are used mos,l/ or 3andling even,s in code: sa/: or sending da,a en,ered

in ,3e orm ,o ,3e da,a*ase and so on1 "3e deaul, even, o ,3e Bu,,on is ,3e Clic9 even,and ,3e Bu,,on class is *ased on ,3e Bu,,onBase class w3ic3 is *ased on ,3e Con,rol class1

B)tton Event "3e deaul, even, o ,3e Bu,,on is ,3e Clic9 even,1 W3en a Bu,,on is clic9ed i,

res.onds wi,3 ,3e Clic9 %ven,1 "3e Clic9 even, o Bu,,on loo9s li9e ,3is in code

Priva,e u* Bu,,on4SClic9(B/Val sender As /s,em1#*+ec,: B/Val e AsS

/s,em1%ven,Args) >andles Bu,,on41Clic9


20/96


Bu,,on41$oca,ionFNew Poin,(400:50)


21/96


"e;,Align Allows ,o align ,3e ,e;, rom ,3ree .ossi*le o.,ions1 "3e deaul, valueis le, and /ou can se, ,3e alignmen, o ,e;, ,o rig3, or cen,er1

croll*ars Allows ,o add a scroll*ar ,o a "e;,*o;1 Ver/ useul w3en ,3e "e;,Bo;is mul,iline1 Eou 3ave our o.,ions wi,3 ,3is .ro.er,/1 #.,ions are are None: >oriDon,al:

Ver,ical and Bo,31 =e.ending on ,3e siDe o ,3e "e;,Bo; an/one o ,3ose can *e used1

Code ,o Valida,e User n.u,We can ma9e sure ,3a, a "e;,Bo; can acce., onl/ c3arac,ers or num*ers w3ic3 can

res,ric, acciden,al o.era,ions1 &or e;am.le: adding ,wo num*ers o ,3e orm 2I2

canno, re,urn an/,3ing1 "o avoid suc3 9ind o o.era,ions we use ,3e e/Press even, o

,3e "e;,Bo;1

Code ,3a, allows /ou ,o en,er onl/ dou*le digi,s in a "e;,Bo; loo9s li9e ,3is Priva,e u* "e;,Bo;4Se/Press(B/Val sender As #*+ec,:B/Val e AsS/s,em1Windows1&orms1e/Press%ven,Args) >andles "e;,Bo;41e/Press

(e1e/C3ar 40 #r e1e/C3ar O 400) "3en

'essageBo;13ow(%n,er =ou*le =igi,s)

%nd %nd u*

reatin( a Te-tBo- in ode

Pu*lic Class &orm4 n3eri,s /s,em1Windows1&orms1&orm

Priva,e u* &orm4S$oad(B/Val sender As /s,em1#*+ec,: B/Val e AsS/s,em1%ven,Args) >andles '/Base1$oad

=im "e;,Bo;4 as New "e;,Bo;()

"e;,Bo;41"e;,F>ello 'a,e"e;,Bo;41$oca,ionFNew Poin,(400:50)

"e;,Bo;41iDeFNew iDe(5:27)

'e1Con,rols1Add("e;,Bo;4)

%nd u*%nd Class

hec


22/96


as c3ec9ed1

C3ec9,a,e =eaul, value is Unc3ec9ed1 e, i, ,o "rue i /ou wan, a c3ec9 ,o a..ear1

W3en se, ,o nde,ermina,e i, dis.la/s a c3ec9 in gra/ *ac9ground1&la,,/le =eaul, value is ,andard1 elec, ,3e value rom a .redeined lis, ,o se, ,3e s,/le

o ,3e c3ec9*o;1

m.or,an, .ro.er,/ in ,3e Be3avior sec,ion o ,3e .ro.er,ies window is ,3e

"3ree,a,e .ro.er,/ w3ic3 is se, ,o &alse */ deaul,1 e, i, ,o "rue ,o s.eci/ i ,3eC3ec9*o; can allow ,3ree c3ec9 s,a,es ,3an ,wo1

Code ,o c3ec9 a C3ec9Bo;andles Bu,,on41Clic9

C3ec9Bo;41C3ec9ed F "rue "3en

"e;,Bo;41"e;, F C3ec9ed%lse

"e;,Bo;41"e;, F UnC3ec9ed%nd %nd u*

Crea,ing a C3ec9Bo; in Code

Priva,e u* &orm4S$oad(B/Val sender As /s,em1#*+ec,: B/Val e AsS

/s,em1%ven,Args) >andlesS '/Base1$oad

=im C3ec9Bo;4 As New C3ec9Bo;()

C3ec9Bo;41"e;, F C3ec9*o;4C3ec9Bo;41$oca,ion F New Poin,(400: 50)

C3ec9Bo;41iDe F New iDe(5: 85)

'e1Con,rols1Add(C3ec9Bo;4)%nd u*

o*boBo-

Com*oBo; is a com*ina,ion o a "e;,Bo; and a $is,Bo;1 "3e Com*oBo;

dis.la/s an edi,ing ield ("e;,Bo;) com*ined wi,3 a $is,Bo; allowing us ,o selec, rom,3e lis, or ,o en,er new ,e;,1 Com*oBo; dis.la/s da,a in a dro.-down s,/le orma,1 "3e

Com*oBo; class is derived rom ,3e $is,Bo; class1 Below is ,3e mage o a Com*oBo;1

Notab+e properties of the o*boBo-

"3e =ro.=own,/le .ro.er,/ in ,3e A..earance sec,ion o ,3e .ro.er,ies window

allows us ,o se, ,3e loo9 o ,3e Com*oBo;1 "3e deaul, value is se, ,o =ro.=own w3ic3means ,3a, ,3e Com*oBo; dis.la/s ,3e "e;, se, */ i,


23/96


We can add i,ems ,o ,3e Com*oBo; wi,3 i,


24/96


dis.la/s a $is,Bo;1

Notab+e Properties of the "istBo-

n ,3e Be3avior ec,ion

>oriDon,alcroll*ar =is.la/s a 3oriDon,al scroll*ar ,o ,3e $is,Bo;1 Wor9s w3en,3e $is,Bo; 3as 'ul,i.leColumns1

'ul,iColumn "3e deaul, value is se, ,o &alse1 e, i, ,o "rue i /ou wan, ,3e lis, *o; ,o

dis.la/ mul,i.le columns1crollAlwa/sVisi*le =eaul, value is se, ,o &alse1 e,,ing i, ,o "rue will dis.la/ *o,3

Ver,ical and >oriDon,al scroll*ar alwa/s1

elec,ion'ode =eaul, value is se, ,o one1 elec, o.,ion None i /ou do no, an/ i,em ,o

*e selec,ed1 elec, i, ,o 'ul,iim.le i /ou wan, mul,i.le i,ems ,o *e selec,ed1 e,,ing i,,o 'ul,i%;,ended allows /ou ,o selec, mul,i.le i,ems wi,3 ,3e 3el. o 3i,: Con,rol and

arrow 9e/s on ,3e 9e/*oard1

or,ed =eaul, value is se, ,o &alse1 e, i, ,o "rue i /ou wan, ,3e i,ems dis.la/ed in ,3e

$is,Bo; ,o *e sor,ed */ al.3a*e,ical order1

Coun,ing ,3e num*er o ,ems in a $is,Bo;

Add a Bu,,on ,o ,3e orm and .lace ,3e ollowing code in i,andles Bu,,on41Clic9

"e;,Bo;41"e;, F $is,Bo;41,ems1Coun,


25/96


%;am.le

Code ,o add and remove da,a

Code ,o 3i, single selec,ed i,em rom one lis,*o; ,o ano,3er lis,*o;Code ,o s3i, mul,i.le i,ems

%;am.le-c3ec9*o; and o.,ion *u,,on

%;am.le-Calcula,or

Code or num*er *u,,ons

Code or #.era,ors *u,,onsCode or euals *u,,ons

o**on Dia+o(s

Visual Basic 1N%" comes wi,3 *uil,-in dialog *o;es w3ic3 allow us ,o crea,e our own

&ile #.en: &ile ave: &on,: Color dialogs muc3 li9e w3a, we see in all o,3er windows

a..lica,ions1 "o ma9e a dialog *o; visi*le a, run ,ime we use ,3e dialog *o;


26/96


SaveFi+eDia+o(

ave &ile =ialog


27/96


"3e Windows &orms TreeVie4con,rol dis.la/s a 3ierarc3/ o nodes: li9e ,3e wa/ iles

and olders are dis.la/ed in ,3e le, .ane o Windows %;.lorer1

"3e Windows &orms TreeVie4con,rol dis.la/s a 3ierarc3/ o nodes: li9e ,3e wa/ ilesand olders are dis.la/ed in ,3e le, .ane o Windows %;.lorer1 %ac3 node mig3, con,ain

o,3er nodes: called c3ild nodes1 Paren, nodes: or nodes ,3a, con,ain c3ild nodes: can *edis.la/ed as e;.anded or colla.sed1 A ,ree view can also *e dis.la/ed wi,3 c3ec9 *o;es

ne;, ,o ,3e nodes: i ,3e ,ree view


28/96


Use ,3e %ven,Args o*+ec, ,o re,urn a reerence ,o ,3e clic9ed node o*+ec,1

=e,ermine w3ic3 node was clic9ed */ c3ec9ing ,3e "reeView%ven,Args class: w3ic3

con,ains da,a rela,ed ,o ,3e even,1

Priva,e u* "reeView4SA,erelec,(B/Val sender As /s,em1#*+ec,: S

B/Val e As /s,em1Windows1&orms1"reeView%ven,Args) >andles"reeView41A,erelec,

1

'essageBo;13ow(e1Node1"e;,)%nd u*

"ISTVIEW ONT%O"

"3e Windows &orms "istVie4con,rol dis.la/s a lis, o i,ems wi,3 icons1 Eou can use a

lis, view ,o crea,e a user in,erace li9e ,3e rig3, .ane o Windows %;.lorer1

"3e Windows &orms "istVie4con,rol dis.la/s a lis, o i,ems wi,3 icons1 Eou can use a

lis, view ,o crea,e a user in,erace li9e ,3e rig3, .ane o Windows %;.lorer1 "3e con,rol

3as our view modes $argecon: mallcon: $is,: and =e,ails1 "3e $argecon modedis.la/s large icons ne;, ,o ,3e i,em ,e;,Q ,3e i,ems a..ear in mul,i.le columns i ,3e

con,rol is large enoug31 "3e mallcon mode is ,3e same e;ce., ,3a, i, dis.la/s small

icons1 "3e $is, mode dis.la/s small icons *u, is alwa/s in a single column1 "3e =e,ails

mode dis.la/s i,ems in mul,i.le columns1

"3e 9e/ .ro.er,/ o ,3e "istVie4con,rol is Ite*s: w3ic3 con,ains ,3e i,ems dis.la/ed */

,3e con,rol1 "3e Se+ectedIte*s.ro.er,/ con,ains a collec,ion o ,3e i,ems curren,l/

selec,ed in ,3e con,rol1 "3e user can selec, mul,i.le i,ems: or e;am.le ,o drag and dro.several i,ems a, a ,ime ,o ano,3er con,rol: i ,3e ')+tiSe+ect.ro.er,/ is se, ,o tr)e1 "3e

"istVie4con,rol can dis.la/ c3ec9 *o;es ne;, ,o ,3e i,ems: i ,3e hec


29/96


41 n ,3e Pro.er,ies window: clic9 ,3e elli.sis *u,,on ( ) ne;, ,o ,3e Ite*s.ro.er,/1

"3e "istVie4Ite* o++ection Editora..ears1

21 "o add an i,em: clic9 ,3e #dd*u,,on1 Eou can ,3en se, .ro.er,ies o ,3e new

i,em: suc3 as ,3e Te-tand I*a(eInde-.ro.er,ies1 "o remove an i,em: selec, i,and clic9 ,3e %e*ove*u,,on1

To add ite*s pro(ra**atica++y

%istView1.&tems.A#'%ist item te(t') $

To add co+)*ns in the desi(ner

41 e, ,3e con,rol


30/96


21 e, ,3e I*a(eInde-or StateI*a(eInde-.ro.er,/ or eac3 lis, i,em ,3a, 3as an

associa,ed icon1

"3ese .ro.er,ies can *e se, in code: or wi,3in ,3e "istVie4Ite* o++ection

Editor1 "o o.en ,3e "istVie4Ite* o++ection Editor: clic9 ,3e elli.sis *u,,on (

) ne;, ,o ,3e Ite*s.ro.er,/ on ,3e Pro.er,ies window1

6 Visal 7asic6 Sets t8e irst list item to isla t8e 9t8 ima4e%istView1.&tems#$.&ma4e&,e( =

OOP=oncept

Obects

Visual *asic allows /ou ,o crea,e o*+ec, */ deining class1Class ma/ 3ave .ro.er,iesand me,3ods1 #*+ec, is a ,3ing w3ic3 is .ro.er,ies and me,3ods1

User deined class can *e crea,ed in v*1and ,3a, classes can *e incor.ora,ed ,o

.ro+ec,s as a reerences1Pro.er,ies are ,3e c3arac,eris,ic and me,3ods are ,3e o.era,ion ,3a, can *e .erormed

on an o*+ec,1

OOP=Ter*ino+o(y

%nca.sula,ion

n3eri,ancePol/mor.3ism

"#SSES

ns,an,ia,ing an o*+ec,

New class name

i1e=im c F new on,(Tarial:42)

$*ln,1on,Fc

reatin( yo)r o4n c+asses

Crea,e a new a..lica,ion o ,/.e class li*rar/Crea,e .ro.er,ies o ,3e class1

Pro.er,/ .rocedure

,3e wa/ ,3a, /our class allows i,s .ro.er,ies is ,o *e accessed is ,3roug3 a .ro.er,/.rocedure1 i, ma/ con,ain a ge, ,o re,rieve a .ro.er,/ value and a se, ,o assign a value

,o ,3e .ro.er,/1



31/96


&ollowing is ,3e e;am.le

Pro.er,/ o.4() As n,eger

Ge,o.4 F no4

%nd Ge,

e,(B/Val Value As n,eger)no4 F Value

%nd e,

%nd Pro.er,/

reatin( yo)r o4n c+asses

Crea,e a new a..lica,ion o ,/.e class li*rar/

Crea,e .ro.er,ies o ,3e class1Pro.er,/ .rocedure

,3e wa/ ,3a, /our class allows i,s .ro.er,ies is ,o *e accessed is ,3roug3 a .ro.er,/.rocedure1 i, ma/ con,ain a ge, ,o re,rieve a .ro.er,/ value and a se, ,o assign a value

,o ,3e .ro.er,/1

&ollowing is ,3e e;am.lePro.er,/ o.4() As n,eger

Ge,

o.4 F no4

%nd Ge,e,(B/Val Value As n,eger)

no4 F Value

%nd e,%nd Pro.er,/

reatin( ne4 obect )sin( c+asses

Crea,e new o*+ec, using ollowing s,a,emen, in windows a..lica,ion

=im c as new class name

"3is class name mus, *e add as a reerence in a .ro+ec,1

!ata Access Tec"nologies'os, a..lica,ions reuire some orm o da,a access1 /ou are crea,ing a new a..lica,ion:

/ou 3ave ,3ree e;cellen, da,a access c3oices A=#1N%": A=#: and #$% =B1 /ouneed ,o modi/ ,3e da,a access or an e;is,ing a..lica,ion: /ou mig3, con,inue using ,3e

a..lica,ionowever: i

/ou e;.ec, ,3e a..lica,ion ,o 3ave a long liec/cle: /ou s3ould consider reengineering ,ouse ei,3er A=#1N%" or managed a..lica,ions or A=# or na,ive a..lica,ions1 n ,3e



32/96


long run: ,3e newer da,a access ,ec3nologies ,/.icall/ reduce develo.men, ,ime: sim.li/

code: and .rovide e;cellen, .erormance1

A!#$%&T

A=#1N%" is ,3e s,ra,egic a..lica,ion-level in,erace or .roviding da,a access services in,3e 'icroso, 1N%" Pla,orm1 Eou can use A=#1N%" ,o access da,a sources using ,3e

new 1N%" &ramewor9 da,a .roviders1 "3ese da,a .roviders include

1N%" &ramewor9 =a,a Provider or $ erver1

1N%" &ramewor9 =a,a Provider or #$% =B1

1N%" &ramewor9 =a,a Provider or #=BC1

1N%" &ramewor9 =a,a Provider or #racle1

"3ese da,a .roviders su..or, a varie,/ o develo.men, needs: including middle-,ier*usiness o*+ec,s using live connec,ions ,o da,a in rela,ional da,a*ases and o,3er s,ores1

A=#1N%" is designed s.eciicall/ or message-*ased We* a..lica,ions w3ile s,ill

.roviding .reera*le unc,ionali,/ or o,3er a..lica,ion arc3i,ec,ures1 B/ su..or,ing

loosel/ cou.led access ,o da,a: A=#1N%" ma;imiDes da,a s3aring */ reducing ,3enum*er o ac,ive connec,ions ,o ,3e da,a*ase reducing ,3e .ossi*ili,/ o mul,i.le users

con,ending or limi,ed resources on ,3e da,a*ase server1

A=#1N%" .rovides several wa/s ,o access da,a1 /our We* a..lica,ion or @'$ We*

service reuires da,a access rom mul,i.le sources: needs ,o in,ero.era,e wi,3 o,3era..lica,ions (*o,3 local and remo,e): or can *enei, rom .ersis,ing and ,ransmi,,ing

cac3ed resul,s: ,3e da,ase, is an e;cellen, c3oice1 As an al,erna,ive: A=#1N%" .rovides

da,a commands and da,a readers ,o communica,e direc,l/ wi,3 ,3e da,a source1 =irec,da,a*ase o.era,ions using da,a commands and da,a readers include running ueries and

s,ored .rocedures: crea,ing

#dvanta(es of #DO.NET over #DO

Interoperabi+ity

A=#1N%" a..lica,ions can ,a9e advan,age o ,3e le;i*ili,/ and *road acce.,ance o

@'$1 Because @'$ is ,3e orma, or ,ransmi,,ing da,ase,s across ,3e ne,wor9: an/

com.onen, ,3a, can read ,3e @'$ orma, can .rocess da,a1 n ac,: ,3e receiving

com.onen, need no, *e an A=#1N%" com.onen, a, all "3e ,ransmi,,ing com.onen, cansim.l/ ,ransmi, ,3e da,ase, ,o i,s des,ina,ion wi,3ou, regard ,o 3ow ,3e receiving

com.onen, is im.lemen,ed1 "3e des,ina,ion com.onen, mig3, *e a Visual ,udio

a..lica,ion or an/ o,3er a..lica,ion im.lemen,ed wi,3 an/ ,ool w3a,soever1 "3e onl/reuiremen, is ,3a, ,3e receiving com.onen, *e a*le ,o read @'$1 As an indus,r/

s,andard: @'$ was designed wi,3 e;ac,l/ ,3is 9ind o in,ero.era*ili,/ in mind1



33/96


'aintainabi+ity

n ,3e lie o a de.lo/ed s/s,em: modes, c3anges are .ossi*le: *u, su*s,an,ial:

arc3i,ec,ural c3anges are rarel/ a,,em.,ed *ecause ,3e/ are so diicul,1 "3a, isunor,una,e: *ecause in a na,ural course o even,s: suc3 su*s,an,ial c3anges can *ecome

necessar/1 &or e;am.le: as a de.lo/ed a..lica,ion *ecomes .o.ular wi,3 users: ,3eincreased .erormance load mig3, reuire arc3i,ec,ural c3anges1 As ,3e .erormance loadon a de.lo/ed a..lica,ion server grows: s/s,em resources can *ecome scarce and

res.onse ,ime or ,3roug3.u, can suer1 &aced wi,3 ,3is .ro*lem: so,ware arc3i,ec,s can

c3oose ,o divide ,3e server


34/96


a..lica,ion mig3, serve a doDen users well: i, mig3, no, serve 3undreds or 3undreds o

,3ousands euall/ well1 An a..lica,ion ,3a, consumes resources suc3 as da,a*ase

loc9s and da,a*ase connec,ions will no, serve 3ig3 num*ers o users well: *ecause ,3euser demand or ,3ose limi,ed resources will even,uall/ e;ceed ,3eir su..l/1

In=*e*ory %epresentations of Data

n A=#: ,3e in-memor/ re.resen,a,ion o da,a is ,3e recordse,1 n A=#1N%": i, is ,3e

da,ase,1 "3ere are im.or,an, dierences *e,ween ,3em1

!ata %a'igation and Cursors

n A=# /ou scan seuen,iall/ ,3roug3 ,3e rows o ,3e recordse, using ,3e A=#

'oveNe-tme,3od1 n A=#1N%": rows are re.resen,ed as collec,ions: so /ou can loo.

,3roug3 a ,a*le as /ou would ,3roug3 an/ collec,ion: or access .ar,icular rows via ordinalor .rimar/ 9e/ inde;1 Data%e+ationo*+ec,s main,ain inorma,ion a*ou, mas,er and de,ail

records and .rovide a me,3od ,3a, allows /ou ,o ge, records rela,ed ,o ,3e one /ou arewor9ing wi,31 &or e;am.le: s,ar,ing rom ,3e row o ,3e &,"estor,a*le or Na,e un:

/ou can naviga,e ,o ,3e se, o rows o ,3e :rc8ase,a*le descri*ing 3is .urc3ases1

A cursoris a da,a*ase elemen, ,3a, con,rols record naviga,ion: ,3e a*ili,/ ,o u.da,e da,a:

and ,3e visi*ili,/ o c3anges made ,o ,3e da,a*ase */ o,3er users1 A=#1N%" does no,3ave an in3eren, cursor o*+ec,: *u, ins,ead includes da,a classes ,3a, .rovide ,3e

unc,ionali,/ o a ,radi,ional cursor1 &or e;am.le: ,3e unc,ionali,/ o a orward-onl/:

read-onl/ cursor is availa*le in ,3e A=#1N%" Data%eadero*+ec,1 &or more inorma,ion

a*ou, cursor unc,ionali,/: see =a,a Access "ec3nologies1

C"oosing A!#$%&T or A!#

Bo,3 A=#1N%" and A=# are eas/ ,o .rogram: language-inde.enden,: im.lemen,ed wi,3

a small oo,.rin,: use minimal ne,wor9 ,raic: and reuire ew la/ers *e,ween ,3e

a..lica,ion


35/96


"3e A=# recordse, is a single ,a*le: accessi*le onl/ as a recordse,: and does no,

con,ain rela,ions3i.s1 An A=# recordse, can *e ,3e resul, o a mul,i.le ,a*le

#N uer/: *u, i, is s,ill onl/ a single resul, ,a*le1 /ou wan, mul,i.le ,a*leswi,3 A=#: /ou mus, 3ave mul,i.le !ecordse, o*+ec,s1 "3e A=#1N%" da,ase,

.rovides *e,,er unc,ionali,/ due ,o i,s in,egra,ed rela,ional s,ruc,ure1

Data sharin( A=#1N%" .rovides ,3e *asis or da,a in,erc3ange *e,ween

com.onen,s and across ,iers da,ase,s can *e .assed over ,3e n,erne, and ,3roug3irewalls as @'$1 Eou can view ,3e same se, o da,a as rela,ional ,a*les wi,3in

/our a..lica,ion and as an @'$ da,a s,ruc,ure in some o,3er a..lica,ion1 "3e

da,ase, .rovides convenien, ,wo-wa/ ,ransorma,ion rom da,ase, ,a*les ,o an@'$ documen,: and rom an @'$ documen, in,o da,ase, ,a*les1

/ou use C#' mars3aling ,o ,ransmi, an A=# recordse,: ,3e ,arge, a..lica,ion

mus, *e .rogrammed ,o use ,3e recordse, da,a s,ruc,ure1 "3is reuires more

diicul, .rogramming ,3an sim.l/ reading @'$ da,a1 Al,erna,ivel/: /ou can

.ersis, ,3e A=# recordse, as @'$ and more easil/ s3are ,3e da,a wi,3 o,3era..lica,ions and services1

Sca+abi+ity A=#1N%" is ,3e mos, scala*le solu,ion1 A=#1N%" is designed rom

,3e ground u. ,o *e ,3e *es, da,a access arc3i,ec,ure or *uilding scala*le We*a..lica,ions wi,3 a low ,o,al cos, o owners3i.1 /ou do no, need ,3e scala*ili,/:

and are no, wri,ing in managed code: /ou can con,inue ,o use A=#1

)rsor +ocation An a..lica,ion can es,a*lis3 resul, se,s in ei,3er o ,wo .laceswi,3in ,3e a..lica,ion .rocess (clien,-side cursor) or wi,3in ,3e da,a s,ore .rocess

(server-side cursor)1 Clien,-side cursors are generall/ a good c3oice or an/ ,/.e

o im.rom.,u user in,erac,ion wi,3 ,3e da,a1 Clien,-side cursors are su..or,ed in

A=#1N%" */ ,3e =a,ae, o*+ec, and in A=# */ ,3e Clien,Cursor !ecordse,o*+ec,1

Introduction to !ata Access it" A!#$%&T

As /ou develo. a..lica,ions using A=#1N%": /ou will 3ave dieren, reuiremen,s or

wor9ing wi,3 da,a1 n some cases: /ou mig3, sim.l/ wan, ,o dis.la/ da,a on a orm1 n

o,3er cases: /ou mig3, need ,o devise a wa/ ,o s3are inorma,ion wi,3 ano,3er com.an/1

No ma,,er w3a, /ou do wi,3 da,a: ,3ere are cer,ain undamen,al conce.,s ,3a, /ou s3ouldunders,and a*ou, ,3e da,a a..roac3 in A=#1N%"1 Eou mig3, never need ,o 9now some

o ,3e de,ails o da,a 3andling or e;am.le: /ou mig3, never need ,o direc,l/ edi, an@'$ ile con,aining da,a *u, i, is ver/ useul ,o unders,and ,3e da,a arc3i,ec,ure in

A=#1N%": w3a, ,3e ma+or da,a com.onen,s are: and 3ow ,3e .ieces i, ,oge,3er1

"3is in,roduc,ion .resen,s a 3ig3-level overview o ,3ese mos, im.or,an, conce.,s1 "3e

,o.ic deli*era,el/ s9i.s over man/ de,ails or e;am.le: ,3ere is muc3 more ,o da,ase,s

,3an w3a, is men,ioned 3ere in avor o sim.l/ in,roducing /ou ,o ideas *e3ind da,ain,egra,ion in A=#1N%"1



36/96


A!#$%&T !oes %ot !epend #n Continuously Li'e Connections

n ,radi,ional clien,Lserver a..lica,ions: com.onen,s es,a*lis3 a connec,ion ,o a da,a*ase

and 9ee. i, o.en w3ile ,3e a..lica,ion is running1 &or a varie,/ o reasons: ,3is a..roac3is im.rac,ical in man/ a..lica,ions

#.en da,a*ase connec,ions ,a9e u. valua*le s/s,em resources1 n mos, cases:

da,a*ases can main,ain onl/ a small num*er o concurren, connec,ions1 "3e

over3ead o main,aining ,3ese connec,ions de,rac,s rom overall a..lica,ion.erormance1

imilarl/: a..lica,ions ,3a, reuire an o.en da,a*ase connec,ion are e;,remel/

diicul, ,o scale u.1 An a..lica,ion ,3a, does no, scale u. well mig3, .erormacce.,a*l/ wi,3 our users *u, will li9el/ no, do so wi,3 3undreds1 AP1N%" We*

a..lica,ions in .ar,icular need ,o *e easil/ scala*le: *ecause ,raic ,o a We* si,e

can go u. */ orders o magni,ude in a ver/ s3or, .eriod1

n AP1N%" We* a..lica,ions: ,3e com.onen,s are in3eren,l/ disconnec,ed rom

eac3 o,3er1 "3e *rowser reues,s a .age rom ,3e serverQ w3en ,3e server 3asinis3ed .rocessing and sending ,3e .age: i, 3as no ur,3er connec,ion wi,3 ,3e

*rowser un,il ,3e ne;, reues,1 Under ,3ese circums,ances: main,aining o.enconnec,ions ,o a da,a*ase is no, via*le: *ecause ,3ere is no wa/ ,o 9now w3e,3er

,3e da,a consumer (,3e clien,) reuires ur,3er da,a access1

A model *ased on alwa/s-connec,ed da,a can ma9e i, diicul, and im.rac,ical ,oe;c3ange da,a across a..lica,ion and organiDa,ional *oundaries using a connec,ed

arc3i,ec,ure1 ,wo com.onen,s need ,o s3are ,3e same da,a: *o,3 3ave ,o *e

connec,ed: or a wa/ mus, *e devised or ,3e com.onen,s ,o .ass da,a *ac9 andor,31

!atabase Interactions Are erformed *sing !ata Commands

"o .erorm o.era,ions in a da,a*ase: /ou e;ecu,e $ s,a,emen,s or s,ored .rocedures

(w3ic3 include $ s,a,emen,s)1 Eou use $ s,a,emen,s or s,ored .rocedures ,o readand wri,e rows and .erorm aggrega,e unc,ions: suc3 as adding or averaging1 Eou also

use $ s,a,emen,s or s,ored .rocedures ,o crea,e or modi/ ,a*les or columns: ,o

.erorm ,ransac,ions: and so on1

n A=#1N%" /ou use da,a commands ,o .ac9age a $ s,a,emen, or s,ored .rocedure1&or e;am.le: i /ou wan, ,o read a se, o rows rom ,3e da,a*ase: /ou crea,e a da,a

command and conigure i, wi,3 ,3e ,e;, o a $ elec, s,a,emen, or ,3e name o a s,ored

.rocedure ,3a, e,c3es records1

W3en /ou wan, ,o ge, ,3e rows: /ou do ,3e ollowing

41 #.en a connec,ion1

21 Call an e;ecu,e me,3od o ,3e command: w3ic3 in ,urn

a1 %;ecu,es ,3e $ s,a,emen, or s,ored .rocedure reerenced */ ,3e

command1



37/96


*1 "3en closes ,3e connec,ion1

"3e connec,ion s,a/s o.en onl/ long enoug3 ,o e;ecu,e ,3e s,a,emen, or

s,ored .rocedure1

W3en /ou call a command


38/96


lConnec,ion - an o*+ec, ,3a, manages a connec,ion ,o a $ erver version 10

or la,er1 , is o.,imiDed or use wi,3 $ erver 10 or la,er */ (among o,3er

,3ings) */.assing ,3e #$% =B la/er1

#le=*Connec,ion - an o*+ec, ,3a, manages a connec,ion ,o an/ da,a s,ore

accessi*le via #$% =B1

#d*cConnec,ion - an o*+ec, ,3a, manages a connec,ion ,o a da,a source crea,ed */using a connec,ion s,ring or #=BC da,a source name (=N)1

#racleConnec,ion - an o*+ec, ,3a, manages a connec,ion ,o #racle da,a*ases1

onnection Strin(s

All connec,ion o*+ec,s e;.ose roug3l/ ,3e same mem*ers1 >owever: ,3e s.eciicmem*ers availa*le wi,3 a given O+eDbonnectiono*+ec, de.end on w3a, da,a source i,

is connec,ed ,oQ no, all da,a sources su..or, all mem*ers o ,3e O+eDbonnectionclass1

"3e .rimar/ .ro.er,/ associa,ed wi,3 a connec,ion o*+ec, is ,3e onnectionStrin(

.ro.er,/: w3ic3 consis,s o a s,ring wi,3 a,,ri*u,eLvalue .airs or inorma,ion reuired ,olog on ,o a da,a*ase and .oin, ,o a s.eciic da,a*ase1 A ,/.ical onnectionStrin(.ro.er,/ mig3, loo9 li9e ,3e ollowing

:ro"ier=S;%O%


39/96


Desi(n=Ti*e onnections in Server E-p+orer

erver %;.lorer .rovides a wa/ or /ou ,o crea,e design-,ime connec,ions ,o da,a sources1

"3is .ermi,s /ou ,o *rowse availa*le da,a sourcesQ dis.la/ inorma,ion a*ou, ,3e ,a*les:columns: and o,3er elemen,s ,3e/ con,ainQ and edi, and crea,e da,a*ase elemen,s1

Eour a..lica,ion does no, direc,l/ use ,3e connec,ions /ou crea,e ,3is wa/1 Generall/: ,3e

inorma,ion .rovided */ a design-,ime connec,ion is used ,o se, .ro.er,ies or a new

connec,ion o*+ec, ,3a, /ou add ,o /our a..lica,ion1

onnection Desi(n Too+s in Vis)a+ St)dio

Eou usuall/ do no, need ,o direc,l/ crea,e and manage connec,ion o*+ec,s in Visual

,udio1 W3en /ou use ,ools suc3 as ,3e =a,a Ada.,er WiDard: ,3e ,ools ,/.icall/ .rom.,

/ou or connec,ion inorma,ion (,3a, is: connec,ion-s,ring inorma,ion) and au,oma,icall/

crea,e connec,ion o*+ec,s or /ou on ,3e orm or com.onen, /ou are wor9ing wi,31

>owever: i /ou wan,: /ou can add connec,ion o*+ec,s /oursel ,o a orm or com.onen,

and se, ,3eir .ro.er,ies1 "3is is useul i /ou are no, wor9ing wi,3 da,ase,s (and ,3ereoreno, wi,3 da,a ada.,ers): *u, ins,ead sim.l/ reading da,a1 Eou mig3, crea,e connec,ion

o*+ec,s /oursel i /ou will *e using ,ransac,ions1

Introduction to !ata Adapters

=a,a ada.,ers are an in,egral .ar, o A=#1N%" managed .roviders: w3ic3 are ,3e se, oo*+ec,s used ,o communica,e *e,ween a da,a source and a da,ase,1 (n addi,ion ,o

ada.,ers: managed .roviders include connec,ion o*+ec,s: da,a reader o*+ec,s: andcommand o*+ec,s1) Ada.,ers are used ,o e;c3ange da,a *e,ween a da,a source and ada,ase,1 n man/ a..lica,ions: ,3is means reading da,a rom a da,a*ase in,o a da,ase,: and

,3en wri,ing c3anged da,a rom ,3e da,ase, *ac9 ,o ,3e da,a*ase1 >owever: a da,a ada.,er

can move da,a *e,ween an/ source and a da,ase,1 &or e;am.le: ,3ere could *e an ada.,er,3a, moves da,a *e,ween a 'icroso, %;c3ange server and a da,ase,1

Generall/: ada.,ers are conigura*le ,o allow /ou ,o s.eci/ w3a, da,a ,o move in,o and

ou, o ,3e da,ase,1 #,en ,3is ,a9es ,3e orm o reerences ,o $ s,a,emen,s or s,ored

.rocedures ,3a, are invo9ed ,o read or wri,e ,o a da,a*ase1

Visual ,udio ma9es ,3ese da,a ada.,ers availa*le or use wi,3 da,a*ases

"3e #le=*=a,aAda.,er o*+ec, is sui,a*le or use wi,3 an/ da,a source e;.osed */

an #$% =B .rovider1

"3e l=a,aAda.,er o*+ec, is s.eciic ,o $ erver1 Because i, does no, 3ave ,ogo ,3roug3 an #$% =B la/er: i, is as,er ,3an ,3e O+eDbData#dapter1 >owever:

i, can onl/ *e used wi,3 $ erver 10 or la,er1

"3e #d*c=a,aAda.,er o*+ec, is o.,imiDed or accessing #=BC da,a sources1



40/96


"3e #racle=a,aAda.,er o*+ec, is o.,imiDed or accessing #racle da,a*ases1

Data #dapters and %e+ated Tab+es

An im.lica,ion o 3aving se.ara,e ,a*les in ,3e da,ase, is ,3a, a da,a ada.,er ,/.icall/

does no, reerence $ commands or s,ored .rocedures ,3a, +oin ,a*les1 ns,ead:

inorma,ion rom ,3e rela,ed ,a*les is read se.ara,el/ in,o ,3e da,ase, */ dieren,ada.,ers1 "3en a Data%e+ationo*+ec, is used ,o manage cons,rain,s *e,ween ,3e da,ase,

,a*les (suc3 as cascading u.da,es) and ,o allow /ou ,o naviga,e *e,ween rela,ed mas,er

and c3ild records1

&or e;am.le: imagine ,3a, /ou are wor9ing wi,3 ,wo rela,ed ,a*les in ,3e Nor,3windda,a*ase: Cus,omers and #rders1 !a,3er ,3an s.eci/ing a +oin ,o com*ine *o,3 ,a*les

in,o a single resul, se,: /ou would mos, commonl/ deine ,wo ada.,ers: one ,o .o.ula,e a

Cus,omers ,a*le in ,3e da,ase, and a second ada.,er ,o read #rder records in,o a dieren,da,ase, ,a*le1 "3e individual ada.,ers would .ro*a*l/ include selec,ion cri,eria ,o limi,

,3e num*er o records in ,3e da,a ,a*les1

n ,3e da,ase, /ou would also deine a Data%e+ationo*+ec, s.eci/ing ,3a, order records

are rela,ed ,o cus,omer records */ ,3e Cus,omer= ield1 Eou can s,ill manage ,3e ,a*lesindividuall/: w3ic3 would no, *e .ossi*le i /ou 3ad +oined ,a*les *eore e,c3ing records

rom ,3e da,a source1 &or si,ua,ions w3ere /ou wan,ed ,o wor9 wi,3 rela,ed records: /ou

can invo9e .ro.er,ies and me,3ods o ,3e Data%e+ationo*+ec,1

#DO.NET o**and Obects

Using an ada.,er: /ou can read: add: u.da,e: and dele,e records in a da,a source1 "o allow

/ou ,o s.eci/ 3ow eac3 o ,3ese o.era,ions s3ould occur: an ada.,er su..or,s ,3e

ollowing our .ro.er,ies

Se+ecto**and reerence ,o a command ($ s,a,emen, or s,ored .rocedurename) ,3a, re,rieves rows rom ,3e da,a s,ore1

Inserto**and reerence ,o a command or inser,ing rows in,o ,3e da,a s,ore1 0pdateo**and reerence ,o a command or modi/ing rows in ,3e da,a

s,ore1

De+eteo**and reerence ,o a command or dele,ing rows rom ,3e da,a s,ore1

"3e .ro.er,ies are ,3emselves o*+ec,s ,3e/ are ins,ances o ,3e lCommand:

#le=*Command: #d*cCommand: or #racleCommand class1 "3e o*+ec,s su..or, a

o**andTe-t.ro.er,/ con,aining a reerence ,o an $ s,a,emen, or s,ored .rocedure1



41/96


Note "3e command class mus, ma,c3 ,3e connec,ion class1 &or e;am.le: i /ou are

using a S>+onnectiono*+ec, ,o communica,e wi,3 a $ erver: /ou mus, also use

commands ,3a, derive rom ,3e S>+o**andclass1

Al,3oug3 /ou can e;.lici,l/ se, ,3e ,e;, o a command o*+ec,: /ou do no, alwa/s need ,oQ

in man/ si,ua,ions: Visual ,udio will genera,e ,3e $ s,a,emen,s needed1 n addi,ion:,3e ada.,er can au,oma,icall/ genera,e a..ro.ria,e $ s,a,emen,s a, run ,ime i ,3e

0pdateo**and: Inserto**and: or De+eteo**ando*+ec,s are no, s.eciied1 &orde,ails: see Au,oma,icall/ Genera,ed Commands1

>owever: /ou can mani.ula,e command o*+ec,s a, design ,ime and run ,ime in order ,o

3ave more direc, con,rol over 3ow ,3e commands are e;ecu,ed1 &or e;am.le: /ou cancrea,e or modi/ ,3e command associa,ed wi,3 a Se+ecto**ando*+ec, +us, *eore i, is

e;ecu,ed1

Eou can also e;ecu,e commands /oursel: inde.enden,l/ o ,3e da,a ada.,er1 "3is allows

/ou ,o .ass ar*i,rar/ $ commands ,3roug3 ,3e da,a ada.,er: suc3 as ,3ose used ,odeine or modi/ da,a*ase deini,ions1 Eou can also call s,ored .rocedures direc,l/ ,3a, do

no, re,urn record se,s or e;am.le: a s,ored .rocedure ,3a, valida,es a user en,r/

o**and Para*eters

"3e commands in a da,a ada.,er are usuall/ .arame,er-driven1 "3e command or ,3e

Se+ecto**and.ro.er,/: or e;am.le: o,en 3as a .arame,er in i,s W>%!% clause so

/ou can s.eci/ a, run ,ime w3a, records ,o ge, rom ,3e da,a*ase1 "3e o,3er commands

use .arame,ers ,3a, allow /ou ,o .ass a, run ,ime ,3e da,a ,o wri,e in,o a record and w3a,record in ,3e da,a*ase ,o u.da,e1 &or more inorma,ion a*ou, 3ow .arame,ers are used in

da,a ada.,ers: see Parame,ers in =a,a-Ada.,er Commands1

%eadin( and 0pdatin( 4ith Data #dapters

"3e .rimar/ .ur.ose o ,3e da,a ada.,er is ,o communica,e da,a *e,ween a da,a s,ore anda da,ase,1 "3e ada.,er su..or,s s.eciic me,3ods ,o move ,3e da,a *ac9 and or,3 *e,ween

,3e ,wo1

Note /ou +us, wan, ,o read da,a (no, u.da,e i,): /ou do no, 3ave ,o s,ore i, in a da,ase,1

ns,ead: /ou can read direc,l/ ou, o ,3e da,a*ase and in,o an a..lica,ion1 &or de,ails: see

!ead-#nl/ =a,a *elow1

Eou can use a da,a ada.,er ,o .erorm ,3e ollowing o.era,ions

!e,rieve rows rom a da,a s,ore in,o corres.onding da,a ,a*les wi,3in ,3e da,ase,1

"o re,rieve rows in,o a da,ase,: use ,3e Fi++me,3od on a da,a ada.,er o*+ec,

(l=a,aAda.,er: #le=*=a,aAda.,er: #d*c=a,aAda.,er: or #racle=a,aAda.,er)1

http://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/vbcon/html/vbconparametersindataadaptercommands.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/vbcon/html/vbconparametersindataadaptercommands.htm


42/96


W3en /ou invo9e ,3e Fi++me,3od: i, ,ransmi,s an $ %$%C" s,a,emen, ,o ,3e

da,a s,ore1

"ransmi, c3anges made ,o a da,ase, ,a*le ,o ,3e corres.onding da,a s,ore1

A!#$%&T !atasets

=a,ase,s are con,ainers cac3es in w3ic3 /ou can s,ore da,a ,o use in /our

a..lica,ion1 =a,ase,s are a undamen,al .ar, o ,3e A=#1N%" arc3i,ec,ure: .roviding*o,3 3ig3-.erormance da,a access as well as scala*ili,/1

=a,ase,s s,ore da,a in a disconnec,ed cac3e1 "3e s,ruc,ure o a da,ase, is similar ,o ,3a, o

a rela,ional da,a*aseQ i, e;.oses a 3ierarc3ical o*+ec, model o ,a*les: rows: and columns1

n addi,ion: i, con,ains cons,rain,s and rela,ions3i.s deined or ,3e da,ase,1

"3e undamen,al .ar,s o a da,ase, are e;.osed ,o /ou ,3roug3 s,andard .rogramming

cons,ruc,s suc3 as .ro.er,ies and collec,ions1 &or e;am.le

"3e =a,ae, class includes ,3e "a*les collec,ion o da,a ,a*les and ,3e !ela,ions

collec,ion o =a,a!ela,ion o*+ec,s1

"3e =a,a"a*le class includes ,3e !ows collec,ion o ,a*le rows: ,3e Columns

collec,ion o da,a columns: and ,3e C3ild!ela,ions and Paren,!ela,ions

collec,ions o da,a rela,ions1

"3e =a,a!ow class includes ,3e !ow,a,e .ro.er,/: w3ose values indica,ew3e,3er and 3ow ,3e row 3as *een c3anged since ,3e da,a ,a*le was irs, loaded

rom ,3e da,a*ase1 Possi*le values or ,3e !ow,a,e .ro.er,/ include De+eted:'odified: Ne4: and 0nchan(ed1

Typed vers)s 0ntyped Datasets

=a,ase,s can *e ,/.ed or un,/.ed1 A ,/.ed da,ase, is a da,ase, ,3a, is irs, derived rom

,3e *ase DataSetclass and ,3en uses inorma,ion in an @'$ c3ema ile (an 1;sd ile) ,o

genera,e a new class1 norma,ion rom ,3e sc3ema (,a*les: columns: and so on) isgenera,ed and com.iled in,o ,3is new da,ase, class as a se, o irs,-class o*+ec,s and

.ro.er,ies1

Because a ,/.ed DataSetclass in3eri,s rom ,3e *ase DataSetclass: ,3e ,/.ed class

assumes all o ,3e unc,ionali,/ o ,3e DataSetclass and can *e used wi,3 me,3ods ,3a,,a9e an ins,ance o a DataSetclass as a .arame,er

An un,/.ed da,ase,: in con,ras,: 3as no corres.onding *uil,-in sc3ema1 As in a ,/.ed

da,ase,: an un,/.ed da,ase, con,ains ,a*les: columns: and so on *u, ,3ose are e;.osed

onl/ as collec,ions1 (>owever: a,er manuall/ crea,ing ,3e ,a*les and o,3er da,a elemen,s



43/96


in an un,/.ed da,ase,: /ou can e;.or, ,3e da,ase,


44/96


=a,a!eader1 Using ,3e =a,a!eader can increase a..lica,ion .erormance *o,3 */

re,rieving da,a as soon as i, is availa*le: ra,3er ,3an wai,ing or ,3e en,ire resul,s o ,3e

uer/ ,o *e re,urned: and (*/ deaul,) s,oring onl/ one row a, a ,ime in memor/: reducings/s,em over3ead1

A,er crea,ing an ins,ance o ,3e Command o*+ec,: /ou crea,e a =a,a!eader */ callingCommand1%;ecu,e!eader ,o re,rieve rows rom a da,a source: as s3own in ,3e ollowing

e;am.le1

XVisual BasicY

=im m/!eader As l=a,a!eader F m/Command1%;ecu,e!eader()

Eou use ,3e %eadme,3od o ,3e Data%eadero*+ec, ,o o*,ain a row rom ,3e resul,s o

,3e uer/1 Eou can access eac3 column o ,3e re,urned row */ .assing ,3e name or

ordinal reerence o ,3e column ,o ,3e Data%eader1 >owever: or *es, .erormance: ,3e

Data%eader.rovides a series o me,3ods ,3a, allow /ou ,o access column values in ,3eirna,ive da,a ,/.es (/etDateTi*e: /etDo)b+e: /et/)id: /etInt9: and so on)1 &or a lis,

o ,/.ed accessor me,3ods

+osin( the Data%eader

Eou s3ould alwa/s call ,3e +oseme,3od w3en /ou 3ave inis3ed using ,3e Data%eadero*+ec,1

/our o**andcon,ains ou,.u, .arame,ers or re,urn values: ,3e/ will no, *e availa*leun,il ,3e Data%eaderis closed1

No,e ,3a, w3ile a Data%eaderis o.en: ,3e onnectionis in use e;clusivel/ */ ,3a,

Data%eader1 Eou will no, *e a*le ,o e;ecu,e an/ commands or ,3e onnection:

including crea,ing ano,3er Data%eader: un,il ,3e original Data%eaderis closed1



45/96


E%%O% $#ND"IN/

Types of &rrors

n Visual Basic: errors (also called exceptions) all in,o one o ,3ree ca,egories s/n,a;errors: run-,ime errors: and logic errors1

Synta+ &rrors

Syntax errorsare ,3ose ,3a, a..ear w3ile /ou wri,e /our code1 Visual Basic c3ec9s /ourcode as /ou ,/.e and aler,s /ou i /ou ma9e a mis,a9e: suc3 as miss.elling a word orusing a language elemen, im.ro.erl/1 /n,a; errors are ,3e mos, common ,/.e o errors1

Eou can i; ,3em easil/ in ,3e coding environmen, as soon as ,3e/ occur1

Note "3e Option E-p+icits,a,emen, is one means o avoiding s/n,a; errors1 , orces

,3e .rogrammer ,o declare: in advance: all ,3e varia*les ,o *e used in ,3e a..lica,ion1"3ereore: w3en ,3ose varia*les are used in ,3e code: an/ ,/.ogra.3ic errors are caug3,

immedia,el/ and can *e i;ed1

Run-Time &rrors

!un"time errorsare ,3ose ,3a, a..ear onl/ a,er /ou com.ile and run /our code1 "3ese

involve code ,3a, ma/ a..ear ,o *e correc, in ,3a, i, 3as no s/n,a; errors: *u, ,3a, will no,e;ecu,e1 &or e;am.le: /ou mig3, correc,l/ wri,e a line o code ,o o.en a ile1 Bu, i ,3e

ile is corru.,ed: ,3e a..lica,ion canno, carr/ ou, ,3e Openunc,ion: and i, s,o.s running1

Eou can i; mos, run-,ime errors */ rewri,ing ,3e aul,/ code: and ,3en recom.iling andrerunning i,1

Logic &rrors

Logic errorsare ,3ose ,3a, a..ear once ,3e a..lica,ion is in use1 "3e/ mos, o,en ,a9e ,3e

orm o unwan,ed or une;.ec,ed resul,s in res.onse ,o user ac,ions1 &or e;am.le: amis,/.ed 9e/ or o,3er ou,side inluence mig3, cause /our a..lica,ion ,o s,o. wor9ing

wi,3in e;.ec,ed .arame,ers: or al,oge,3er1 $ogic errors are generall/ ,3e 3ardes, ,/.e ,o

i;: since i, is no, alwa/s clear w3ere ,3e/ origina,e1

%rror messages can occur w3ile an a..lica,ion is running: ei,3er wi,3in ,3e VisualBasic 1N%" environmen, or as a s,and-alone e;ecu,a*le1 ome o ,3ese can also occur

during design ,ime or com.ile ,ime1 Eou can ,es, and res.ond ,o ,ra..a*le errors using



46/96


,3e On Error s,a,emen, and ,3e Erro*+ec,


47/96


Str)ct)red E-ception $and+in(

n s,ruc,ured e;ce.,ion 3andling: *loc9s o code are enca.sula,ed: wi,3 eac3 *loc9 3aving

one or more associa,ed 3andlers1 %ac3 3andler s.eciies some orm o il,er condi,ion on,3e ,/.e o e;ce.,ion i, 3andles1 W3en an e;ce.,ion is raised */ code in a .ro,ec,ed

*loc9: ,3e se, o corres.onding 3andlers is searc3ed in order: and ,3e irs, one wi,3 ama,c3ing il,er condi,ion is e;ecu,ed1 A single me,3od can 3ave mul,i.le s,ruc,urede;ce.,ion 3andling *loc9s: and ,3e *loc9s can also *e nes,ed wi,3in eac3 o,3er1

"3e Try...atch...Fina++ys,a,emen, is used s.eciicall/ or s,ruc,ured e;ce.,ion

3andling1 &or more inorma,io1

0nstr)ct)red E-ception $and+in(

"3e OnErrors,a,emen, is used s.eciicall/ or uns,ruc,ured e;ce.,ion 3andling1 n

uns,ruc,ured e;ce.,ion 3andling: On Erroris .laced a, ,3e *eginning o a *loc9 o code1, ,3en 3as sco.e over ,3a, *loc9Q i, 3andles an/ errors occurring wi,3in ,3e *loc91 ,3e

.rogram encoun,ers ano,3er On Errors,a,emen,: ,3a, s,a,emen, *ecomes valid and ,3eirs, s,a,emen, *ecomes

Try$$$Catc"$$$,inally Statements

Provides a wa/ ,o 3andle some or all .ossi*le errors ,3a, ma/ occur in a given *loc9 o

code: w3ile s,ill running code1

Try

? tryStatements@? Catch? exception?Astype@ @ ?Whenexpression@

? catchStatements@ @? Exit Try@...? Finally ? finallyStatements@ @End Try

Parts

tryStatements#.,ional1 ,a,emen,(s) w3ere an error can occur1 Can *e a com.ound s,a,emen,1

atch

#.,ional1 'ul,i.le atch*loc9s .ermi,,ed1 an e;ce.,ion occurs w3ile

.rocessing ,3e Try*loc9: eac3 atchs,a,emen, is e;amined in ,e;,ual orderexception

#.,ional1 An/ varia*le name1 "3e ini,ial value o exceptionis ,3e value o ,3e

,3rown error1 Used wi,3 atch,o s.eci/ ,3e error caug3,1



48/96


When

#.,ional1 A atchs,a,emen, wi,3 a Whenclause will onl/ ca,c3 e;ce.,ions

w3en expressionevalua,es ,o Tr)e1 A When clause is onl/ a..lied a,er c3ec9ing,3e ,/.e o ,3e e;ce.,ion: and expressionma/ reer ,o ,3e iden,iier re.resen,ing

,3e e;ce.,ion1

expression#.,ional1 'us, *e im.lici,l/ conver,i*le ,o Boo+ean1 An/ e;.ression ,3a,

descri*es a generic il,er1 "/.icall/ used ,o il,er */ error num*er1 Used wi,3

When9e/word ,o s.eci/ circums,ances under w3ic3 ,3e error is caug3,1catchStatements

#.,ional1 ,a,emen,(s) ,o 3andle errors occurring in ,3e associa,ed Try*loc91 Can

*e a com.ound s,a,emen,1

E-it Try#.,ional1 e/word ,3a, *rea9s ou, o ,3e Try...atch...Fina++y s,ruc,ure1

%;ecu,ion resumes wi,3 ,3e Fina++y*loc9 i .resen,: o,3erwise wi,3 ,3e code

immedia,el/ ollowing ,3e End Trys,a,emen,1 No, allowed in Fina++y*loc9s1

Fina++y#.,ional1 A Fina++y*loc9 is alwa/s e;ecu,ed w3en e;ecu,ion leaves an/ .ar, o

,3e Trys,a,emen,1#inallyStatements

#.,ional1 ,a,emen,(s) ,3a, are e;ecu,ed a,er all o,3er error .rocessing 3as

occurred1

End Try

"ermina,es ,3e Try...atch...Fina++ys,ruc,ure1

"3e Try*loc9 con,ains code w3ere an error can occur: w3ile ,3e atch*loc9 con,ains

code ,o 3andle an/ error ,3a, does occur1 an error occurs in ,3e Try*loc9: .rogram

con,rol is .assed ,o ,3e a..ro.ria,e atchs,a,emen, or dis.osi,ion1 "3e exceptionargumen, is an ins,ance o ,3e E-ceptionclass or an ins,ance o a class ,3a, derives rom

,3e E-ceptionclass corres.onding ,o ,3e error ,3a, occurred in ,3e Try*loc91 "3e

E-ceptionclass ins,ance con,ains inorma,ion a*ou, ,3e error including: among o,3er,3ings: i,s num*er and message1

:ri"ate Sb 7tto,1ClicB#7Val se,er As Sstem.Object) 7Val e As Sstem.


49/96


:blic Sb Tr


50/96


An #rraycan 3ave mul,i.le dimensions: w3ile an #rray"istalwa/s 3as e;ac,l/

one dimension1

An #rrayo a s.eciic ,/.e (o,3er ,3an Obect) 3as *e,,er .erormance ,3an an

#rray"ist*ecause ,3e elemen,s o #rray"istare o ,/.e Obectand: ,3ereore:

*o;ing and un*o;ing ,/.icall/ occur i s,oring or re,rieving a value ,/.e1

'os, si,ua,ions ,3a, call or an arra/ can use #rray"istins,ead1 , is easier ,o use and: in

general: 3as .erormance similar ,o an arra/ o ,/.e Obect1

#rrayis in ,3e Syste*names.aceQ #rray"istis in ,3e Syste*.o++ectionsnames.ace1

P)b+ic Properties

Ca.aci,/ Ge,s or se,s ,3e num*er o elemen,s ,3a, ,3e #rray"istcan con,ain1

Coun,

Ge,s ,3e num*er o elemen,s ac,uall/ con,ained in ,3e #rray"ist1

s&i;ediDe Ge,s a value indica,ing w3e,3er ,3e #rray"ist3as a i;ed siDe1

s!ead#nl/

Ge,s a value indica,ing w3e,3er ,3e #rray"istis read-onl/1

s/nc3roniDedGe,s a value indica,ing w3e,3er access ,o ,3e #rray"istis s/nc3roniDed (,3read-sa

P)b+ic 'ethodsAda.,er

Crea,es an #rray"istwra..er or a s.eciic $is,1

AddAdds an o*+ec, ,o ,3e end o ,3e #rray"ist1

Add!ange

Adds ,3e elemen,s o an Collec,ion,o ,3e end o ,3e #rray"ist1

Binar/earc3#verloaded1 Uses a *inar/ searc3 algori,3m ,o loca,e a s.eciic elemen, in ,3e

sor,ed #rray"istor a .or,ion o i,1

Clear !emoves all elemen,s rom ,3e #rray"ist1

Clone

Crea,es a s3allow co./ o ,3e #rray"ist1

Con,ains=e,ermines w3e,3er an elemen, is in ,3e #rray"ist1

Co./"o

#verloaded1 Co.ies ,3e #rray"istor a .or,ion o i, ,o a one-dimensional arra/1

http://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclasscapacitytopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclasscounttopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassisfixedsizetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassisreadonlytopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassissynchronizedtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassadaptertopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsilistclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassaddtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassaddrangetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsicollectionclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassbinarysearchtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclasscleartopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassclonetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclasscontainstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclasscopytotopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclasscapacitytopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclasscounttopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassisfixedsizetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassisreadonlytopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassissynchronizedtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassadaptertopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsilistclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassaddtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassaddrangetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsicollectionclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassbinarysearchtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclasscleartopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclassclonetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclasscontainstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsarraylistclasscopytotopic.htm


51/96


%uals

#verloaded1 =e,ermines w3e,3er ,wo #*+ec,ins,ances are eual1

nser,nser,s an elemen, in,o ,3e #rray"ista, ,3e s.eciied inde;1

nser,!ange

nser,s ,3e elemen,s o a collec,ion in,o ,3e #rray"ista, ,3e s.eciied inde;1!emove

!emoves ,3e irs, occurrence o a s.eciic o*+ec, rom ,3e #rray"ist1

!e.ea,

!e,urns an #rray"istw3ose elemen,s are co.ies o ,3e s.eciied value1

!everse

#verloaded1 !everses ,3e order o ,3e elemen,s in ,3e #rray"istor a .or,ion o i,

>as3,a*le Class

A $ashtab+econsis,s o *uc9e,s ,3a, con,ain ,3e elemen,s o ,3e collec,ion1 A *uc9e, is a

vir,ual su*grou. o elemen,s wi,3in ,3e $ashtab+e: w3ic3 ma9es searc3ing and re,rievingeasier and as,er ,3an in mos, collec,ions1 %ac3 *uc9e, is associa,ed wi,3 a 3as3 code:

genera,ed using a 3as3 unc,ion and *ased on ,3e 9e/ o ,3e elemen,1

A 3as3 unc,ion is an algori,3m ,3a, re,urns a numeric 3as3 code *ased on a 9e/1 "3e 9e/is ,3e value o some .ro.er,/ o ,3e o*+ec, *eing s,ored1 A 3as3 unc,ion mus, alwa/s

re,urn ,3e same 3as3 code or ,3e same 9e/1 , is .ossi*le or a 3as3 unc,ion ,o genera,e

,3e same 3as3 code or ,wo dieren, 9e/s: *u, a 3as3 unc,ion ,3a, genera,es a uniue

3as3 code or eac3 uniue 9e/ resul,s in *e,,er .erormance w3en re,rieving elemen,srom ,3e 3as3 ,a*le1

W3en an o*+ec, is added ,o a $ashtab+e: i, is s,ored in ,3e *uc9e, ,3a, is associa,ed wi,3

,3e 3as3 code ,3a, ma,c3es ,3e o*+ec,


52/96


,em Ge,s or se,s ,3e value associa,ed wi,3 ,3e

s.eciied 9e/1

e/s Ge,s an Collec,ioncon,aining ,3e 9e/s in,3e $ashtab+e1

/nc!oo, Ge,s an o*+ec, ,3a, can *e used ,o

s/nc3roniDe access ,o ,3e $ashtab+e1

Values Ge,s an Collec,ioncon,aining ,3e values in

,3e $ashtab+e1

P)b+ic 'ethods

AddAdds an elemen, wi,3 ,3e s.eciied 9e/ and

value in,o ,3e $ashtab+e1

Clear !emoves all elemen,s rom ,3e $ashtab+e1

Clone Crea,es a s3allow co./ o ,3e $ashtab+e1

Con,ains =e,ermines w3e,3er ,3e $ashtab+econ,ains

a s.eciic 9e/1

!emove !emoves ,3e elemen, wi,3 ,3e s.eciied 9e/

rom ,3e $ashtab+e1

"o,ring !e,urns a,ring,3a, re.resen,s ,3e curren,

#*+ec,1

SortedList Class

"3e or,ed$is, class is li9e a 3/*rid *e,ween >as3,a*le and Arra/$is,1

As wi,3 $ashtab+e: Sorted"istis *ased on ,3e =ic,ionar/ in,eraceQ ,3ereore: eac3

elemen, o a Sorted"istis a 9e/-and-value .air1 Sorted"ist.rovides me,3ods ,3a, re,urn

onl/ ,3e lis, o 9e/s or onl/ ,3e lis, o values1

As wi,3 #rray"ist: a Sorted"istis a seuence o elemen,s1 , is inde;ed: and is sor,ed

according ,o a s.eciied com.arer1

Sorted"istis uniue among all Collec,ions classes in ,3a, eac3 elemen, can *e accessed,3ree wa/s using ,3e 9e/: ,3e value: or ,3e inde;1

http://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclassitemtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclasskeystopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsicollectionclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclasssyncroottopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclasssyncroottopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclassvaluestopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclassvaluestopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsicollectionclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclassaddtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclasscleartopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclassclonetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclasscontainstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclassremovetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemobjectclasstostringtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemstringclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemstringclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemobjectclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclassitemtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclasskeystopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsicollectionclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclasssyncroottopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclassvaluestopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionsicollectionclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclassaddtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclasscleartopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclassclonetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclasscontainstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionshashtableclassremovetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemobjectclasstostringtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemstringclasstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemobjectclasstopic.htm


53/96


P)b+ic Properties

Ca.aci,/Ge,s or se,s ,3e ca.aci,/ o ,3e Sorted"ist1

Coun,Ge,s ,3e num*er o elemen,s con,ained in

,3e Sorted"ist1

s&i;ediDe Ge,s a value indica,ing w3e,3er ,3e

Sorted"ist3as a i;ed siDe1

s!ead#nl/ Ge,s a value indica,ing w3e,3er ,3e

Sorted"istis read-onl/1

s/nc3roniDed Ge,s a value indica,ing w3e,3er access ,o

,3e Sorted"istis s/nc3roniDed (,3read-

sae)1

,em Ge,s and se,s ,3e value associa,ed wi,3 as.eciic 9e/ in ,3e Sorted"ist1

e/s Ge,s ,3e 9e/s in ,3e Sorted"ist1

/nc!oo, Ge,s an o*+ec, ,3a, can *e used ,o

s/nc3roniDe access ,o ,3e Sorted"ist1

ValuesGe,s ,3e values in ,3e Sorted"ist1

P)b+ic 'ethods

AddAdds an elemen, wi,3 ,3e s.eciied 9e/ and

value ,o ,3e Sorted"ist1

Clear!emoves all elemen,s rom ,3e Sorted"ist1

CloneCrea,es a s3allow co./ o ,3e Sorted"ist1

Con,ains=e,ermines w3e,3er ,3e Sorted"istcon,ains

a s.eciic 9e/1

Serialiation.inder Class

Allows users ,o con,rol class loading and manda,e w3a, class ,o load1

P)b+ic 'ethods

Bind"o"/.eW3en overridden in a derived class: con,rols

,3e *inding o a serialiDed o*+ec, ,o a ,/.e1

http://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasscapacitytopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasscounttopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassisfixedsizetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassisreadonlytopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassissynchronizedtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassitemtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasskeystopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasssyncroottopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassvaluestopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassaddtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasscleartopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassclonetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasscontainstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemruntimeserializationserializationbinderclassbindtotypetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasscapacitytopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasscounttopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassisfixedsizetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassisreadonlytopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassissynchronizedtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassitemtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasskeystopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasssyncroottopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassvaluestopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassaddtopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasscleartopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclassclonetopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemcollectionssortedlistclasscontainstopic.htmhttp://ms-help//MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/cpref/html/frlrfsystemruntimeserializationserializationbinderclassbindtotypetopic.htm


54/96


%uals(in3eri,ed rom Obect)#verloaded1 =e,ermines w3e,3er ,wo #*+ec,

ins,ances are eual1

Ge,>as3Code(in3eri,ed rom Obect)e

visual programming.pdf

Documents