VB .NET Revisit VB .NET Revisit

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

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

Building HelloWorld with Visual Studio .NET VB .NET Revisit

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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