1. VB .NET Revisit
VB .NET Revisit

2. Software Development Life Cycle
Problem Definition
Requirement Analysis
Systems Design
Implementation
Testing & Debugging
Deployment
Maintenance
VB .NET Revisit

3. VB .NET .NET CLR-compliant language Event-driven Object Oriented
Visual Studio .NET
A Rapid Application Development (RAD) environment
An Integrated Development Environment (IDE)
Editor, Command Line Compiler
VB .NET Revisit

4. Building HelloWorld with Visual Studio .NET
VB .NET Revisit

5. Hello World - Console A Console application
Imports System ‘ import System namespace
Public Module Hello ‘ a Standard Module
Public Sub Main()
Console.WriteLine("Hello World!")
End Sub
End Module
A Console application
To compile (by command line compiler):
vbc HelloWorld.vb
To execute:
HelloWorld.exe
VB .NET Revisit

6. Hello World - GUI VB .NET Revisit
Imports System ' import System namespace
Imports System.Drawing
Imports System.Windows.Forms
Public Class HelloWindows
Inherits Form ' inherits System.Windows.Forms.Form
Private lblHelloWindows As Label
Public Shared Sub Main()
Application.Run(New HelloWindows())
End Sub
Public Sub New() ' constructor
lblHelloWindows = New Label()
With lblHelloWindows
.Location = New Point(37,31)
.Size= New Size(392,64)
.Font = New Font("Arial",36)
.Text = "Hello, Windows!"
.TabIndex = 0
.TextAlign = ContentAlignment.TopCenter
End With
Me.Text = "Visual Basic .NET"
AutoScaleBaseSize = New Size(5, 13)
FormBorderStyle = FormBorderStyle.FixedSingle
ClientSize = New Size(466,127)
Controls.Add(lblHelloWindows)
End Class
VB .NET Revisit

7. Hello World - GUI A Windows Application To compile: To execute:
vbc HelloWorld2.vb /reference:System.dll,System.Drawing.dll,System.Windows.Forms.dll /target:winexe
To execute:
HelloWorld2.exe
VB .NET Revisit

8. Class Public Class Student ‘ a base class … End Class
Public Class FtStudent
Inherits Student
Dim s1 As New Student()
Dim s2 As New FtStudent()
s1 = s2
VB .NET Revisit

9. Access Modifiers
Control the accessibility of types and types members (including fields, methods, etc.)
Public Class SomeClass
Public Sub DoSomething()
End Sub
Private Sub InternalHelperSub()
End Class
Control the accessibility of types and types members (including fields, methods, etc.)
Private: accessible only from within the context in which it is declared
Protected: from within the program in which it is defined and the derived classes
Public: publicly accessible
VB .NET Revisit

10. Fundamental Types Boolean Byte Short Integer Long Decimal Single
Double
Char
String
Date
Object
VB .NET Revisit

11. Variables, Literals Dim bFlag As Boolean = False
Dim datToday As Date = #01/01/2005#
Dim iValue As Integer
Dim lValue As Long
Dim shValue As Short = 128
Dim sngValue As Single
Dim dblValue As Double
Dim MyString As String
VB .NET Revisit

12. Type Conversion Implicit Type Conversion: Char -> String
Byte -> Short -> Integer -> Long -> Decimal -> Single -> Double
Explicit Type Conversion (Casting):
CByte()
CShort()
CInt()
CLng()
CDec()
CSng()
CDbl()
CBool()
CChar()
CStr()
CDate()
VB .NET Revisit

13. Assignment Statements
Dim a, b As SomeClass
a = New SomeClass()
a.MyPublicMember = “value in a”
b = a
b = New SomeClass()
VB .NET Revisit

14. Operators +, -, *, / \ (integer division) Mod (modulo), 9 Mod 2
^ (exponentiation), X^2
=, <>, <, <=, >, >=, AND, OR, NOT, XOR
TypeOf …Is, TypeOf(x) Is String
Is, s1 Is s2
Like, s1 Like "a*“
VB .NET Revisit

15. Basic I/O Module Module1 Sub Main() Dim n As Integer Dim s As String
Console.Out.WriteLine("HelloWorld! What's your name?")
s = Console.In.ReadLine() ‘ read in a string
Console.Out.WriteLine("How old are you?")
n = Console.In.ReadLine() ‘ read in a number
Console.Out.WriteLine("Hi " + s + ", you're " + CStr(n) + " already.")
‘ or Console.Out.WriteLine("Hi {0}, you're {1} already.", s, n)
Console.In.ReadLine() ‘ wait to press Enter
End Sub
End Module
VB .NET Revisit

16. Branching Statements (1)
Call SomeMethod() or
SomeMethod()
Exit Do, Exit For, Exit Function, Exit Sub, Exit Try
If A = B Then
statements
End If
Else
ElseIf expression Then
VB .NET Revisit

17. Branching Statements (2)
Select Case strColor
Case “red” …
Case “green”, “blue”
Case Else
End Select
VB .NET Revisit

18. Loop Do While I < 10 … Loop Do Loop Until I >= 10
For i = 0 to 4 Step 2
Console.WriteLine(i)
Next
For Each i in iArrary ‘ iArrary is an array
For Each obj In col ‘ col is a collection
Console.WriteLine(obj.ToString())
VB .NET Revisit

19. Array Dim a(4) As Integer For i = 0 to 4 Console.WriteLine(a(i)) Next
a = New Integer(2) {}
a(0) = 1
a(1) = 2
Dim a() As String = {“First”, “Second”, “Third”}
Dim a(5,10) As Integer
VB .NET Revisit

20. Enumeration Module Module1 Enum CardSuit clubs = 0 diamonds = 1
hearts = 2
spades = 3
End Enum
Sub Main()
Dim cs As CardSuit = CardSuit.hearts
System.Console.Out.WriteLine("The value cs is {0}", cs)
End Sub
End Module
VB .NET Revisit

21. Structure Module Module1 Structure PixelCoord Public x As Single
Public y As Single
End Structure
Sub Main()
Dim p As PixelCoord
p.x = 200
p.y = 100
System.Console.Out.WriteLine("The value p.x is {0}", p.x)
System.Console.Out.WriteLine("The value p.y is {0}", p.y)
End Sub
End Module
VB .NET Revisit

22. Collection Dim col As New Collection() col.Add(“First item”)
col.Add(“Second item”)
col.Add(“Third item”)
Dim obj As Object
For Each obj In col
Console.WriteLine(CType(obj, String))
Next
Dim i As Integer
For i = 1 to col.Count
Console.WriteLine(CType(col(i), String))
VB .NET Revisit

23. Sub & Function Sub CheckInput() … End Sub
Function Square(ByVal i as Integer) As Integer
Return x
End Function
VB .NET Revisit