Chapter 1Introduction toVisual Basic.NET : Chapter 1Introduction toVisual Basic.NET Programming In
Visual Basic.NET
Writing Windows Applications with VB : 2 Writing Windows Applications with VB Windows Graphical User Interface
Window = Form
Toolbox of elements called Controls
Text Box
Label
Check Box
Button
Programming Languages : 3 Programming Languages Procedural
Program specifies exact sequence
Event Driven (VB 6.0 and previous)
Object Oriented Programming (VB.NET)
User controls sequence
Click event
Double Click event
Change event
Object Model : 4 Object Model Object ==> Noun
Form and Controls
Property ==> Adjective
Color of a Form
Method ==> Verb
Move a Form
Object Model (cont.) : 5 Object Model (cont.) Event ==> Occur when the user takes action
User clicks a button, User moves a form
Class ==> Template to create new object
Each control added is an Instance of a Class
Dot Notation : 6 Dot Notation Used to reference object's properties and methods in code
Object dot Property
Form.Text, TextBox.Text
Object dot Method
Form.Hide( ), TextBox.Focus( )
To reference an object's events use an underscore instead of a dot
Button_Click, ListBox_TextChanged
Object Model Analogy : 7 Object Model Analogy Class = automobile
Properties = make, model, color, year
Object = each individual car
Object is also an Instance of the automobile class
Methods = start, stop, speedup, slowdown
Events = car arrives, car crashes
Visual Basic.NET : 8 Visual Basic.NET Included in Visual Studio.NET
Visual Basic (can also be purchased separately)
C++
C#
.NET Framework
Complete rewrite from VB Version 6
Visual Studio.NET Editions : 9 Visual Studio.NET Editions Academic
Professional
Enterprise Developer
Enterprise Architect
Steps for Writing VB Projects : 10 Steps for Writing VB Projects Design/Define the User Interface
Plan/Set the Properties
Plan/Write the Code
Test and Debug
VB Application Files : 11 VB Application Files One Solution File .sln
Solution User Options File .suo
Project Files .vbproj
Project User Options File .vbproj.user
Form Files .vb
Resource File for the Form .resx
Visual Studio Environment : 12 Visual Studio Environment Integrated Development Environment (IDE)
Form Designer
Editor for entering code
Compiler
Debugger
Object Browser
Visual Studio IDE Start Page : 13 Visual Studio IDE Start Page
IDE New Project Dialog : 14 IDE New Project Dialog
IDE Main Window : 15 IDE Main Window Toolbars
Document Window
Form Designer
Solution Explorer
Properties Window
Toolbox
IDE Main Window : 16 IDE Main Window
VB Toolbox : 17 VB Toolbox Holds the tools you place on a form
Visual Studio Help : 18 Visual Studio Help Extensive Help feature
Includes Microsoft Developer Network library (MSDN)
Entire reference manual
Coding examples
Modes : 19 Modes Design Time
Run Time
Break Time “Look at the Title Bar”
Naming Rules (p 43-44) : 20 Naming Rules (p 43-44) Always use standard names for objects
No spaces or punctuation marks
3 letter lowercase prefix identifies control type
Button-btn
Label-lbl
Form-frm
If multiple words capitalize 1st letter of each word
Recommended Naming Conventions for VB Objects : 21 Recommended Naming Conventions for VB Objects
Hello World Project (p 13) Design the User Interface : 22 lblMessage btnPush btnExit Hello World Project (p 13) Design the User Interface
Properties Window-Label1 : 23 Properties Window-Label1 Rename Label1 to lblMessage
Set the Properties : 24 Set the Properties Label
Name lblMessage
Text leave blank
Button 1
Name btnPush
Text Push Me
Button 2
Name btnExit
Text Exit
Form
Name frmHello
Text Hello World by your name
Set the Project's Startup Object : 25 Set the Project's Startup Object The default startup object if Form1
The name of the form should always be changed to adhere to naming rules
Using Project menu, Properties change the startup object to match the new name
Project Property Page Dialog : 26 Project Property Page Dialog
Write the Code : 27 Write the Code While the project is running the user can perform actions
Each action by the user causes an Event to occur
Write code for the events you care about, the events you want to respond with code
Code is written as event procedures
VB will ignore events for which you do not write code
Editor Window : 28 Editor Window Declarations Section
Class list
Method list
Remark Statement : 29 ' Display the Hello World message Remark Statement Also known as Comment, used for documentation
Non-executable
Automatically colored Green in Editor
Begins with an apostrophe ( ' )
On a separate line from executable code
At the right end of a line of executable code
Assignment Statement : 30 lblMessage.Text=" Hello World " Assignment Statement Assigns a value to a property or variable
Operates from right to left
Enclose text strings in quotation marks (" ")
Ending a Program : 31 Ending a Program Execute the Close Method of the Form
Methods always have parentheses (this will help you distinguish them from Properties which never have parentheses)
Current Form may be referenced as Me Me.Close( )
Test and Debug : 32 Test and Debug Save Project - File Menu, Save All
Run Project
Debug Menu, Start
Start Without Full Compile (F5)
Start With Full Compile (CTRL F5)
Correct any Errors and Rerun
Compile errors
Run-Time Errors
Logic errors
Syntax errors "Help is always available from the Help Menu or by pressing F1."
Print the Code : 33 Print the Code File Menu, Print
Prints complete code listing
Uses arrow symbol to denote line continuation
Examine sample output on page 39
Finding and Fixing Errors : 34 Finding and Fixing Errors Syntax Errors
Run-Time Errors
Logic Errors