1. Visual Basic.

2. Integrated Development Enviroment
Generates startup form for new project on which to place controls.
Features toolbox from which controls can be selected & placed on form.
Features intellisense which prompts for completion of statement or object reference.
Provides immediate syntax checking.
Provides online debugging, displaying intermediate values.
Provides HELP feature.

3. Toolbox and Controls
Label control
Textbox
control
Button
Toolbox

4. Basic Controls Label : Displays information through its Text property.
Textbox : Information Entry, Display, and Transfer through its Text Property. Use name of textbox to access information or respond to Gotfocus event.
Button : Information Display through its Text Property. Use name of button to respond with subroutine to its Click event.

5. Event Driven Programming
Before event driven programs, typical applications were executed by the computer under control of the application.
With event driven programs, the operating system detects user interactions (mouse click, tab key, etc.), passes them to the application, and a control responds by running a subprogram.

6. Controls and Associated Events
Form
Load event occurs when form is loaded into computer memory
Button
Click event occurs when user clicks button with mouse
Textbox
Lostfocus event occurs when user tabs out of box

7. Click event for Avg button
Private Sub cmdAvg_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdAvg.Click
'Compute average and store in text property of tbAvg control
tbAvg.Text = (CInt(tbNum1.Text) + CInt(tbNum2.Text)) / 2
tbNum1.Select()
tbNum1.SelectionStart = 0
tbNum1.SelectionLength = tbNum1.Text.Length
tbNum2.Clear()
lblStep1.Visible = True
lblStep2.Visible = False
End Sub

8. Variables and Data Types
Variables are assigned values from a data type
VB data types include String, Integer, Double, and Boolean
A Dim statement is used to declare a variable and the data type from which its values are assigned

9. Syntax of Dim and Assignment Statements
Dim <variable> as <data-type>
Dim avg as double
Dim nmbr as integer
Dim flag as boolean
Assignment
<variable> = <expression>
avg = (nmbr1 + nmbr2) / 2
flag = false

10. Variables and Assignment Statements
Dim message As String ‘declares string variable
'Assign string constant to messages 1 and 2
‘Assignment statement : <variable> = <expression>
message = "Enter numbers to be “ & _ “averaged in 1st and 2nd textboxes“
lblStep1.Text = message
message = "Click Average button"
lblStep2.Text = message

11. Creating a New Project Open Visual Studio 2005 Click Project after
Create:

12. Choosing Project Language, Template, and Project Name
Select Visual Basic
Windows
Windows Application
Enter Project Name (Lab1 in example)
Click OK

13. View Startup Form and Set Properties

14. Problem Analysis & Application Development
Analyze Problem
Example :
Find averages of pairs of numbers, number1 and number2
Input : number1, number2
Process : average = (number1 + number2) / 2
Output : average

15. Project Implementation & Software Development
Design Solution
Choose forms and controls
Select label – textbox pairs for
Input : number1 and number2 and
Output : average
Select buttons to launch processes
Average
Write code to implement process
Gets number1 and number2 values
Computes average = (number1 + number2) /2
Displays average

16. Select Label Control from Toolbox
Click on Form to position Label – drag if desired.
Click on Textbox Control from Toolbox
Click on Form to position Textbox to right of Label

17. Name textbox tbNumber1
Holding shift key down, select label and textbox together
Copy with Ctrl-C
Paste with Ctrl-V (for Number2 entry.
Select button Control and position below label – textbox pair
Paste again below button for output.
Set text properties of labels and the button
Name textbox and button controls
Write code for button click event – double click on button to generate subroutine shell
Label – textbox pair
Copy with Ctrl-C

18. Controls after selection
Now set text properties of labels and the button
Name textbox and button controls
Write code for button click event – double click on button to generate subroutine shell

19. Controls after setting text properties of labels and the button
Name textbox and button controls
Name of textbox for output
Write code for button click even by double clicking button
Button code should
Compute & display average
Clear input boxes and select first box

20. Write code for button click event by double clicking button
Button code performs following:
Computes average
Displays average
Clears input boxes and selects first box

21. Test Program in debugger by switching back to design view
Click debugger button

22. Copy Screen to Copy Buffer by doing a Print Screen
Paste onto a Word Document
Type your name & turn in.

23. Data types and Statement Types
Values
Statement
Syntax
Integer
3, 211, -42, .
Declaration
Dim <variable> as <datatype>
Double
3.17, 1.414
Assignment
<variable> = <exp>
String
“Hello”, “Bob”
Selection
If <condition> then
<statement_list>
End if
Boolean
True, False
Repetition
For <variable> = <start> to <end>
Next

24. Controls and Associated Events
Form
Load event occurs when form is loaded into computer memory
Button
Click event occurs when user clicks button with mouse
Textbox
Lostfocus event occurs when user tabs out of box
Listbox
SelectedIndexChanged occurs when user clicks a list item with mouse

25. Problem Analysis & Application Development
Analyze Problem
Example :
Find average of list of numbers incrementally by
Keeping track of number of numbers
Keeping track of sum of numbers
Computing average after each number
Displaying numbers in a listbox

26. Average of List of Grades

27. If statement for Control
If statement performs an action (<statement_list>) if a condition (<condition>) is true.
Syntax :
If <Condition> then
<statement_list>
End if

28. If statement Example with Else part
Syntax with Else
If <Condition> then
<statement_list1>
Else
<statement_list2>
End if
Example :
If hours > 40 then
overtimeHours = hours – 40
overtimeHours = 0
End If