حتى الإحتراف فيجوال بيسك 2008 (الفصل 1 إلى 6)

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2008

: 2008 2008 software applications .

2008 , , ( ,) .

. 2008 2008 , C++ 2008 ,C# 2008 Web Developer 2008 .....

2008 ( ) ,standard edition ,Professional Edition Team Suite (Express Edition

) 2005

, 2008 . 2008

: 2 2003 1

(2008 ,Standard Edition Professional Edition TeamSuite(

: GHz 1.6 MB RAM 384, 7681024, , 5400RPM / .,

2.2: 1024 (10241280 : 2.4 GHz768 MB RAM) ) .

2008 professional edition standard edition

21 ,24 ,VB6

, windows applications web application classes and customcontrols console visual tools . :

-1 integrated development environment of Visual Studio-2 windows applications

Development Environmentthe IntegratedExploring ,2008 Integrated(2008

Development Environment(IDE)( , 2008 IDE) , ... ...

, Microsoft Visual Studio Integrated Development Environment IDE . ,

C++ ,#C :2008 -1 Start / Windows taskbar /All Programs 2008folder )Visual Studio

) /2008 )Microsoft Visual Studio 2008(2008 2008 ,

-2 2008 , , Visual Basic development

, , ( ) tool windows Start Page , )MSDN)Microsoft development net

.

.

)integrated development environment)IDE IDE)( . IDE

/

. The Start Page

Multiple Documents Tabbed Documents view : Tools menu Options Options

General Window Layout

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Tabbed Documents OK .

, vb2008

, ,

)1.1( Recent Projects

Recent Projects link ,Open Project

( Open Project )CTRL+O .

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)10(

: )help( )about( . 2008 2005 .

2008 2005 ...2003 : ( ) projects or solutions

, , 2008 VBPROJproject file.)( (solution file (.SLN , Windows Explorer 9 :

. cala )sln.( )cala( )vbproj.( )visual basic project( .

2008 ).VB 9( project file , ,projects , project group files (vbg.)

,6 single project ,solution project file(.vbproj) (solution file (.sln ( ) a

project solution-multi , 2008 .,

( )Always Show Solution solutions ,IDE Tools Options

General) ) /Projects and Solutions solution ,

solutions ,IDE File Solution Explorer ,

MSDN: Visual Studio )MSDN)the Microsoft Developer Network , , , .

Getting Started ( )

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al Studio HeadlinesVisu announcements

, Tools menu Import And Export Settings location ,

next , , 2008 , :

General Development Settings, Visual Basic Development Settings, and Web Development Settings Visual Basic Development Settings

Finish .

starting anew project

, , ( ) File menu New Project CreateProject/Solution )in the Start Page(

, Windows Forms Applications forms((windows, Console ,text window Windows Forms

Control Libraries , .

)1.2( Visual Basic 2008 Express Edition

Create Directory For Solution ( ) Location

( ) . Save All MenuFile , discard Visual Studio ,

Windows Forms Application template WindowsApplication1 , Create Directory For Solution ok ( 2008

) .

)1.3( 2008 , Form1 Solution Explorer IDE

Form Designer design mode ( ) ,

, View menu

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Toolbars( submenu 28 ( )toggles toolbars ( ) ,

)Layout and Standard) toolbars . Toolbars submenu Customize

, , , , .

Using the Windows Form Designer Display the Designer

( form ) (user interface ) :

Solution Explorer , )view( Solution Explorer

:MusicTrivia.vb

( , , , ) ( ) )control( your form)(

, )Common Controls tab( . ,

, ,

., Properties window ( ( )) IDE ) Solution Explorer( , , View Properties

Window ,F4 , PropertiesBrowser , their role Appearance header Behavior , AZ button

, alphabetical order .

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)1,4(

retracts to the left edge of the Designer

( )Toolbox window )is docked( )floating(

)fixed, docked, floating( . ( ) Thinking About Properties:

each user interface element ( ) , ,Properties window (

). , , :

inherent characteristics brand name ( , ) terminology ( characteristics) properties ,

, ( , , ) ., intangible ( ) , , , , ( ).

Text (Textbox control )Located My Textbox(Control( , Text ( )the controls caption

Text property )( BackColor , ,

three tabs ( Custom Web )System ( ) , yellow .

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)15(

font ( )+ , ellipsis button ,

ok , Textbox )Verdana, 14 points, bold

controls Text property , handles perimeter

. (Label ) button CheckBox

, TextBox AutoSize accommodate , , TextBox

MultiLine ( )True vertically : )forms(

bold style ,excess inherits

, , consistent look

)bold or italics( verdana segoe ui

segoe handwritten graphical application color creative

, new discipline Microsofts Expression Studio interface ,

Expression m/expressionwww.microsoft.co , function Multiline

False (,True ) toggles ( / ) TextBox . Multiline TextBox

( )FalseMultiline =( (if Multiline = True) True Text , Enter . WORDWRAP true False .

Scroll Bar , Scrollbars arrow None, Vertical, Horizontal, and(

Both( ( , , ) . ,Vertical , ( ,) ,

)multiline TextBox( Dock Properties window Fill

. F5 ,

)16(

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Creating Your First VB Application ,

, VB good ,VB new project Windows Application1 TextBox Button )form(

)17( Font (Segoe UI, 9 pt 9, )

Text ) your favorite programming languageEnter( AUTOSIZE

,)True( aligned snap lines , , event handlers ,click of a button ,the selection of a menu command ,the click of a check box . , .

, , , underscore , ,

Word Wrap (on ) .edit>advance>word wrap

)18( editor :

Private Sub Button1 Click(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles Button1.Click

End Sub [Form1.vb [Design the Form1.vb

( ) ( ) , (

) . ( ) ( ) Button1 Objects list Events list

button Click Button control _Button1

Click subroutine . click Button1 Button1_ Click , ,

, 24 Button control , .events , signature ( arguments )

VB 2008 two arguments : sender argument , e argument

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, ( )EvaluateLanguage , Handles . Handles

Button1.Click, ,Button1 , Button2 Button2.Click, , ( ,)

. , TextBox keystrokes , (CheckBox

( )) ( ) , ScrollBar , ( ,)

, , Button1 bttnEvaluate :

Private Sub Button1_ Click(ByVal sender As System.Object, _

ByVal e As System.EventArgs) Handles bttnEvaluate.ClickEnd Sub , , ,

, , ( )txt, lbl, bttn , bttnEvaluatetxtLanguage

, Button1, Button2, Button3 promote , .

Click Button1 , Visual Basic (End SubPrivate Sub

)Private Sub EvaluateLanguage(ByVal sender As System.Object, _

ByVal e As System.EventArgs) Handles Button1.ClickDim language As Stringlanguage = TextBox1.Text

If language = Visual Basic ThenMsgBox(We have a winner!)ElseMsgBox(language & is not a bad language.)End If End Sub

TextBox language variable )named location( . ( ) , dim ,

language Dim language = TextBox1.Text: ( ,) language variable

Visual Basic OK ( )8 OK ,

2008 , , . .very robust

VISUAL BASIC ToUpper method String class language

variable uppercase language .ToUpper VB ,VB 2008 , ( ) . ComboBox

revise .Making the Application More User-Friendly

)WindowsApplication2( , Create Directory For Solution IDE , File menu Save All Browse

, ComboBox Button )1,9( Evaluate My Choice . text

)1,9( ComboBox , ComboBox Items

Collection Items ( )

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)110( items ComboBox

text box ComboBox , :

C++C#Visual BasicJavaCobol

ok , , , , text )select your favorite programming language(: . , F5 ,

, tab ( spacebar ) , , ( toolbar ) debug>stop debugging .

, , end subPrivate SubPrivate Sub Button1 Click(ByVal sender As System. Object, _

ByVal e As System.EventArgs) Handles Button1.ClickDim language As Stringlanguage = ComboBox1.TextIf language = Visual Basic ThenMsgBox(We have a winner!)

ElseMsgBox(language & is not a bad language.)End If End Sub

ComboBox , .

Private Sub Form1 Load(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles MyBase.Load

End Sub Visual Basic .

Private Sub Form1 Load(ByVal sender As System. Object, _ ByVal e As System.EventArgs) Handles MyBase.Load

ComboBox1.SelectedIndex = 2End Sub

SelectedIndex ComboBox , , SelectedIndex Visual Basic :

If ComboBox1.SelectedIndex = 2 ThenMsgBox(We have a winner!)

ElseMsgBox(ComboBox1.Text & is not a bad language.)

End If text ComboBox , , ,ComboBox interpreted ,

ComboBox , , DisplayStyle DROPDOWN DROPDOWNLIST ,

bulletproof robust .Understanding the IDE Components

IDE Visual Studio 2008 , ,

The IDE Menu , toolbars

( )disabled edit menu

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, data menu altogether , XML xml

File Menu

save all ) .

Edit Menu

advanced IntelliSense

> ( Advanced Submenu>Edit) Advanced

View White Space ( )Space characters ) periods Word Wrap .

/ Comment Selection/Uncomment Selection , , .

( ,) ( ). ( )

> ( IntelliSense Submenu>Edit) Edit > IntelliSense , ( ) ( ) , ( )

, , , ( its arguments( : List Members

)on( ( , , , ) . , TextBox1

.TextBox1) ( )1,11( ToolTip text (=)

"TextBox1.Text = "Your User Name: , ( )1,12

TextBox1.TextAlign =

. ( ) ( esc end( enter

)1,11(

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)1,12(

Parameter Info

Go To Definition InfoQuick

IntelliSense ( ( ) (ToolTip box ) bold

, . Complete Word

Ctrl+ spacebar TEXTB Ctrl+ spacebar )TextBox, TextBox1(

Insert Snippet Insert Snippet , 2008

. > ( Outlining Submenu>Edit)

( ) outlining , Click , reduce

(+) , (+) . -( ) collapse . outlining outlining

, ) off( outlining . substantial amount :

Outlining ExpansionToggle ( ) procedures definition ( ) .

Toggle All Outlining ,

. Stop Outlining

( / ) Start Automatic Outlining .

Collapse To Definitions .

View Menu IDE Toolbars menu " "

, WindowsOutput and Command console ,Output window , VB

Project Menu

( form ,file component )another project Project Properties , Add Reference and Add WebReference NET web )NET components and web components.( Build Menu

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( ) , Build ,Rebuild All ( executable ( , The Rebuild All ( )the solution . Debug Menu

Data Menu

, 2322 . Format Menu

( ) . .

Tools Menu (Macros ) macros

, IDE options , Choose Toolbox Items

Toolbox Window Menu

Hide devoted , retracted .

.corresponding tab MenuHelp

MSDN Toolbox Window

applications interface retracted

( , )& Toolbars tabsCommon Controls and Menus)(

Solution Explorer Window solution , hierarchical list ,

, , , ( ) Set As Startup Project Add Item

Exclude From Project , , delete .

Properties Window ( Properties Browser)

, , . relatively few , Color

properties Color dialog box , , Collection Editor Dialog box

ComboBox , , >View ,Properties Window properties F4 ,

overlap ComboBox , , . Output Window

, , , >View > Output

. ( and Immediate WindowsCommand)

, .breakpoint ,suspended Immediate Immediate ,

result interrupted ? Math.Log (35)

? The answer is & result.ToString Debug. Write .Debug.WriteLine

. ,

Immediate (a time-honored practice ) VB WriteLine immediate DateDiff() function :Debug.WriteLine(DateDiff(DateInterval.Day, #3/9/2007#, #5/15/2008#))

433 Immediate ( )DateDiff() function . Immediate , ( )

functionality Immediate window Stop End If handler Click event , , , ,

Immediate IDE Debug menu Windows

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Margin , Debug. Start AddProj . hardly in designing or debugging applications

Error List Window . IDE

, MsgBox() function ()MssgBox . wiggly red line

Name MssgBox is not declared Setting Environment Options

Setting Environment Options . , Tools menu (Options

) Options )113( , , , , , )114( , Created

check box . Temp folder run the Disk Cleanup utility(to claim more space( . VS F5

(Before Building ) (Build And Run page ) Project And Solutions branch >File )Save All(

.

)113(

)114(

console

Using Code Snippets

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2008 , , , ( )

edit IntelliSense

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, , My , , : Play method WAV file :

)CountDown.wav\Sounds\C:.Computer.Audio.Play(My :

.Computer.Audio.PlaySystemSound(System.Media.SystemSounds.Exclamation)My plays back Play method WriteAllText method

My object , , My object My :

.ApplicationMy CommandLineArgs property My. Application

command-line arguments

( ) . Info property (DirectoryPath ,) Product Name, Version .Computer My , , Computer.AudioMy.

My.Computer.Clipboard , ,ContainsTextContainsImage,ContainsData, and ContainsAudio, GetText, GetImage, GetData, and GetAudioStream

. PictureBox :

If My.Computer.Clipboard.ContainsImage ThenPictureBox1.Image = My.Computer.Clipboard.GetImage

End If If My.Computer.Clipboard.ContainsText Then

TextBox2.Text = My.Computer.Clipboard.GetTextIf End

My . With :

With My.Computer.ClipboardIf .ContainsImage Then

PictureBox1.Image = .GetImageEnd If If .ContainsText Then

TextBox2.Text = .GetTextEnd If

End With With With

, With , End With Computer My. FileSystem . :

My.Computer.FileSystem FileSystem DeleteDirectory ,DeleteFileRenameFileRenameDirectoryWriteAllText, ReadAllText, ToolTip

CopyFile :My.Computer.FileSystem.CopyFile(sourceFileName As String , destinationFileName As _ String ,overwrite As Boolean )

overwrite argument , usual copy animation ,as the file is being copied /

, ( )overloaded forms , , .

Forms )forms( , , .

Settings , ( an XML configuration file) xml

Settings .User

, )User component( CurrentPrincipal property

( credentials) Web Services . .

, .Framework My , My substitute Framework , Framework ,

, . (, )15 :My

Dim files As ReadOnlyCollection( Of String )files = My.Computer.FileSystem.GetFiles( "D:\Data" , True , "*.txt")

etFilesG files collection pathnames :Data\D , , GetFiles ( )oussynchron

)block( , 15 . my , , (

productivity( My , . My ( ) , penalty My ( )

Framework

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)2(

Variables and Data Types ( )

, , ( ) )scope( )lifetime( ,

( )

: ( )

native

arrays :

immediate window Debug.WriteLine MsgBox

Variables Username ( ) Discount 0.35 DiscountUsername

(( )0.35) ( ) ( ( )alphanumeric) 0.35 , (" ") , , ,

, , 2008 , CommonLanguage Runtime (CLR) , .

, , Dim As .Dim Amount As Decimal

Decimal integer noninteger $24,500 button

:Private Sub Button1_Click( ByVal sender As System.Object, ByVal e As System.EventArgs)_ Handles Button1.Click

Dim Amount As DecimalDim Discount As DecimalDim DiscountedAmount As DecimalAmount = 24500Discount = 0.35DiscountedAmount = Amount * (1 - Discount)MsgBox( "Your price is $" & DiscountedAmount.ToString)

End Sub 0.35 Discount

, )option strict is on( ,) off( treats )Double value( ( ) Double .Decimal

Decimal type nt = 0.35DDiscou

D , )type characters( )financial calculations(

Discount Discount . 0.35 :

0.35)-DiscountedAmount = 24500 * (1 Discount )program is up-to-date.Entirethe(

( ) Declaring Variables ,

. , Discount

, Discount . BASIC )intensely criticized( , , , in advance ,

, Date . VB 2008 ,

VB 2008 . , VB ( )

. Dim As , :

Dim meters As Integer StringAsgreetingsDim

meters 3 1002 greetings , , :

StringAs, CardNumDecimalAs, AmountInteger AsQtyDim commas

DoubleAs, Volume, AreaInteger AsLength, Width, HeightDim Integer .Double fractional

)floating-point values( greater accuracy . , Private, Public, and Static access modifiers

,

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Dim )module( Count (subroutine , ) , Count

. Naming Conventions-Variable

( ) : letter digits punctuation symbols underscore character 255 characters scope

. VB 2008 case-insensitive myAge, myage, and MYAGE

. Variable Initialization

2008 . Integer ( ) 3,045= 3045Integer AsdistanceDim

:

Dim distance As Integer distance = 3045

, Dim quantity As Integer = 1, discount As Single = 0.25

( Type Inference) )trademark features of BASIC(

, , , . 2008 ,

, Integer : Dim count = 2999 , GetType method . TOSTRING

property System.Int32 :Immediate windowDebug.WriteLine(count.GetType.ToString)

count Integer type Value of type Date cannot be converted to Integer .

subsequent inference )module(Option Infer Off

) off( ,)option strict( ) off( Object variable , . )option strict on( , :

As clause Option Strict On requires all variable declarations to have an .

Types of Variables :

Numeric String

Boolean Date ( Object)

( ) , disadvantages

Integer variables integers . .necessary conversions

. , . ,

( ) . Numeric Variables

:o (Integers )o Decimalso ( ) Single, or floating-point numbers with limited precisiono Double ( ) floating-point numbers with extreme precision

( ) accurately exclusively .scientific calculations

.whole numbers . ( ) ) trade-off( precision execution(

). less-precise data types are manipulated faster

Variablesinteger , .

, )anticipate( ,

Long Short . MINVALUE MAXVALUE minimum maximum

respectively represented corresponding (Short (Int16 (Integer (Int32 (Long (Int64 )reverse( . Integer

offending wiggly .

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Dim shortInt As Int16Dim Int As Int32Dim longInt As Int64

Debug.WriteLine(Int16.MinValue)Debug.WriteLine(Int16.MaxValue)Debug.WriteLine(Int32.MinValue)Debug.WriteLine(Int32.MaxValue)Debug.WriteLine(Int64.MinValue)Debug.WriteLine(Int64.MaxValue)shortInt = Int16.MaxValue + 1

' ERROR, exceeds the maximum value of the Short data type( , (Int = Int16.MaxValue + 1' OK, is within the range of the Integer data type( 32 ( ( Int = Int32.MaxValue + 1

' ERROR, exceeds the maximum value of the Integer data type( integer , (Int = Int32.MinValue - 1

' ERROR, exceeds the minimum value of the Integer data type( integer , ( longInt = Int32.MaxValue + 1' OK, is within the range of the Long data type( 64) (longInt = Int64.MaxValue + 1

' ERROR, exceeds the range of all Integer data types ( , ( WriteLine ,

, :in type Short Constant expression not representable) ,))short( .

data type ( ) Byte (Byte)) byte 1 ) 0 255Signed Byte (sbyte))

byte 1 ) 128- 127

Short (Int16)) 16 byte 2 ) 32768- 32767Integer (Int32)) 32 byte 4 ) 2,147,483,648 2,147,483,647

Long (Int64)) 64 byte 8 ) 9,223,372,036,854,755,808 9,223,372,036,854,755,807 )Unsigned Short (UShort)

16 byte 2 ) 0 65,535

Unsigned Integer (UInteger)) 32 bytes 4 ) 0 4,294,967,295

Unsigned Long (ULong)) 64 bytes 8 ) 0 18,446,744,073,709,551,615

Single Precision (Single)( ( bytes 4 ))

3.402823E38 1.401298E-45 1.401298E-45 3.402823E38

0 ( )

Double Precision (Double) ( ( bytes 8 )

( ) 1.79769313486232E308 4.94065645841247E-324 4.94065645841247E-324 1.79769313486232E308

Decimal (Decimal) ( ( bytes 16) ( 0 )28

1: byte= (8( )bit( 8 ( )

: -1 1 31 -2 32 127 -3 127 .

)charactersUnicode( 2 Precision Numbers-and Double-Single

Single Double single-precision double-precision . . .

3 / 1 (. . .0.333333 )3 256 256MB RAM 3 ( truncated( ( ) :truncation :

Dim a As Single , b As Double :

a = 1 / 3Debug.WriteLine(a)

:immediat.3333333

,decimal point Ctrl+ Break :a = a * 100000Debug.WriteLine(a)

:immediat33333.34

rounded a 100,000 0.3333334:

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.(0.3333333) multiplied it by 100,000 Singlevariable , (error propagation ) . errors propagate

)tolerate( Single )cumulative errors( ( ) .significant )double-precision numbers( .b

:b = 1 / 3Debug.WriteLine(b)b = b * 100000Debug.WriteLine(b)

immediat:0.333333333333333,33333.3333333333

.

: 0 .1 ( )convenient , ,)(on and off ,As a matter of fact (bits )zeros and ones .

)binary numbering system( decimal system , , , whole or fractional )( ( ,

) decimal numbering system , ..binary system

.illuminating example a single-precision variable b double-precisionvariable :

Dim a As Single , b As Doublea = 0.03007b = 0.03007

(Debug.WriteLine(a - b : 6.03199004634014E-10-

0.000000000603199004634014 , .

Eventually mathematical notation , . 1/3 3 ) .1(

1/3 ,3 1/3 , 3 (1/3) ., ba Single Double , (: )

a = 3b = 1 / aDebug.WriteLine(a * b)

as Decimal ( )0.999999999999999999999999999 28 .

The Decimal Data Type (integers ) 16 )bytes 16( ( ( ) ,) of 10 is scaled by a power(10

( scaling power) , 0 28 0 )1( (0^10 ( ) ) . ( ( )10 28 28^10

28 ( ) 28 . (integer 79,228,162,514,264,337,593,543,950,335)

, ( ) )0( ,)0^10( 28 (7.9228162514264337593543950335 ). (

)8 .extreme accuracy ((factor ) ,28) )(01. . .0.00( 27

)1 . ,)you have at your disposal( .

, ( ) integers 235.85 23585 )scale down( (100 )2^10 . ( )100 )102( ( ,) )100(

100 , 12.4051 * 328.558: integers , . , 124051 * 328558: , ( Scientific

view( 40,757,948,458 4,075.7948458 .,Decimal data type :

Dim a As Decimal = 328.558DDim b As Decimal = 12.4051DDim c As Decimalc = a * bDebug.WriteLine(c.ToString)

D converted , )fractional part( Double. ( )Strict option is on

Decimal type D ( .).type character (truncated ) 4,075.795

. , , ideal .financial applications .Doubles ( )

)Type Characters(

C char "A"c=StringAschDim

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D or @ Decimal type = 12.99DDecimalAspriceDimR or # Double type = 3.14 RDoubleAspiDimI or % Integer type Dim count As Integer = 99IL or & Long type Dim distance As Long = 1999L

S Short type Dim age As Short = 1SF or ! Single type = 74.99FSingleAsvelocityDim

Infinity and Other Oddities Framework (NAN: ) )Infinity(, NAN , ( )confirm , . ,

NAN , (Not a Number (NAN.((NAN). , (NAN). ,

.. . Log() function ,

, . , annoying , ,(throwing an exception ) ,

. , : ,

, 2008 ( ) (: .) TOSTRING method .Infinity: , Double variable :

Dim dblVar As Double = 999Dim infVar As DoubleinfVar = dblVar / 0MsgBox(infVar)

Infinity , ( ) , . make sense .

yield non-number , :

Dim largeVar As Double = 1.0E+299Dim smallVar As Double = 1.0E-299Dim result As Doubleresult = largeVar / smallVar MsgBox(result)

1E299 10 299 1E-299 10 -299 10 1E299.

, . ( ) . 0 / 0 . :

Dim var1, var2 As DoubleDim result As Doublevar1 = 0var2 = 0result = var1 / var2MsgBox(result)

( ).NAN :

Dim result As Doubleresult = result + resultresult = 10 / resultresult = result + 1.0E+299MsgBox(result)

Testing for Infinity and NAN . NaN IsNaN IsInfinity . Integer

.. TrueIsInfinity IsNegativeInfinity and IsPositiveInfinity. , ,

.Dim var1, var2 As Double

Dim result As Doublevar1 = 0var2 = 0

result = var1 / var2If Double .IsInfinity(result) ThenIf Double .IsPositiveInfinity(result) Then

MsgBox( "Encountered a very large number. Cant continue" )Else

MsgBox( "Encountered a very small number. Cant continue" )

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End If Else

If Double .IsNaN(result) ThenMsgBox( "Unexpected error in calculations" )

ElseMsgBox( "The result is : " & result.ToString)

End If End If

Byte Variables . ( ,)

0 .255 image .,sound files , )charactersUnicode( 2 . :

Dim n As Byte n , .,

:Dim A As Byte , B As ByteA = 233B = 50

overflow exceptionDebug.WriteLine(A + B)

immediat windowA first chance exception of type 'System.OverflowException' occurred in WindowsApplication1.exe

B = A + B: 283 .

with BytesBoolean Operations overflows ,AND, OR, NOT, and XOR .

)True or False( ( ,AND, OR, NOTand XOR( . 200199 AND 192 1100100011000111

( sebitwi )0=01,1=10,1=00 AND 11000000 .192 Byte data type VB 2008 (Signed Byte data type SByte)

128 .127 bit 1 0 ( )0

sBoolean Variable

( / )True/False in essence (integers ) (1 )True 0( )False , Dim failure As:

Boolean False , Dim failure As Boolean = False :

ments ... other state

If failure Then MsgBox(Couldnt complete the operation) And, Or, Not, and Xor Not (toggles / ) .

toggle(running = Not running( running True False . :Dim running As BooleanIf running = True Thenrunning = FalseElserunning = True

If End , ( ) ReadOnly and

Hidden ) (True( ( presumably) )If ReadOnly Or Hidden Then

MsgBox( "Couldnt open the file" )Else{ statements to open and process file}

If End if OR ( )parenthesized( negated Not operator If clause negation ,True

ReadOnly )True( (Hidden )is False ( ( eFalsOr True(NotIf() ( )= :

TrueNotIf ( )= )False(

String Variables , StringAssomeTextDim: someText

2 ( 2 ) :Dim aString As String

aString = "Now is the time for all good men to come " & " to the aid of their country"aString = ""aString = "There are approximately 25,000 words in this chapter"aString = "25,000"

, .,

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Dim aNumber As Integer = 25000Dim aString As String = "25,000"

aString ,2,5 00,0, aNumber ( ,) aString aNumber , necessary conversions Strict option ) off(

.

Character Variables 2 ,)2bytes( ,)(Unsigned Short integers (UInt16(

CChar() function CInt() function , Char .Char Aschar1, char2Dim , Aa

Dim : char1 As Char = "a", char2 As Char = "ABC"Debug.WriteLine(char1)Debug.WriteLine(char2)

Strict option , char1 and char2 Dim Ac=Char As, char2ac=Char Aschar1Dim:

, ANSI) ))Americam Ntional Standard Institute( , :65

Debug.WriteLine(Convert.ToInt32( "A"c)) 945 Unicode value ,960

. , , . Char data type ., password

, Dim password As String , ch As Char

Dim i As Integer Dim valid As Boolean = FalseWhile Not valid

password = InputBox( "Please enter your password" )For i = 0 To password.Length - 1

ch = password.Chars(i)If Not Char .IsLetterOrDigit(ch) Then

valid = TrueExit For

End If NextIf valid Then

MsgBox( "You new password will be activated immediately!" )Else

MsgBox( "Your password must contain at least one special symbol!" )End If

End While