1. Tutorial 12 – Security Panel Application Introducing the Select Case Multiple-Selection Statement
Outline
12.1 Test-Driving the Security Panel Application Introducing the Select Case Multiple-Selection Statement Constructing the Security Panel Application Wrap-Up

2. In this tutorial, you will learn to:
Objectives
In this tutorial, you will learn to:
Use the Select Case multiple-selection statement.
Use Case statements.
Use the Is keyword.
Display a date and time.
Use TextBox property PasswordChar.

3. 12.1 Test-Driving the Security Panel Application

4. 12.1 Test-Driving the Security Panel Application
Load the Wage Calculator application
Debug > Start

5. 12.1 Test-Driving the Security Panel Application
Figure 12.1　Security Panel application executing.
TextBox
Keypad
Output ListBox

6. 12.1 Test-Driving the Security Panel Application
Figure 12.2　Asterisks displayed in Security code: field.
An asterisk is displayed for each numeric key pressed

7. 12.1 Test-Driving the Security Panel Application
Entering invalid code
Enter 1212
Click # Button

8. 12.1 Test-Driving the Security Panel Application
Figure 12.3　Security Panel displaying Access Denied message.
Message indicating that an invalid security code was entered

9. 12.1 Test-Driving the Security Panel Application
Entering valid code
Enter 1006
Click # Button

10. 12.1 Test-Driving the Security Panel Application
Figure 12.4　Security Panel application confirming a valid security-code entry.
Message displayed when a valid security code is entered

11. 12.2 Introducing the Select Case Multiple-Selection Statement
Select Case statement
Begins with keywords Select Case followed by test expression
Can contain optional Case Else statement
Terminates with keywords End Select

12. 12.2 Introducing the Select Case Multiple-Selection Statement
Figure 12.5　Select Case multiple-selection statement UML activity diagram.

13. 12.3 Constructing the Security Panel Application

14. 12.3 Constructing the Security Panel Application

15. 12.3 Constructing the Security Panel Application
Figure 12.7　Variable declarations for btnEnter_Click.
Declaring event handler’s variables
Declaring variables
Clearing the TextBox

16. 12.3 Constructing the Security Panel Application
Creating Case statement
Specify a range of values using:
Keyword Is
Comparison operator (in this case, <)

17. 12.3 Constructing the Security Panel Application
Figure 12.8　Select Case statement.
Creating a Select Case statement
Create Select Case statement
Set controlling expression

18. 12.3 Constructing the Security Panel Application
Figure 12.9　First Case added to Select Case statement.
Is keyword can be used for relational and equality comparisons

19. 12.3 Constructing the Security Panel Application
Creating a Case statement
Specifying a range of values using:
Keyword To
Checking for a specific number
Specifying multiple expressions
Use a comma to separate expressions

20. 12.3 Constructing the Security Panel Application
Figure 12.10　Cases specified for remaining access codes.
To keyword can be used to specify a range of values to test.
Comma used to separate multiple expressions in a Case

21. 12.3 Constructing the Security Panel Application
Creating a Case Else statement
Use keywords Case Else
Must follow all other Case statements

22. 12.3 Constructing the Security Panel Application
Figure 12.11　Case Else of the Select Case statement.
Case Else statement executes when no other case matches

23. 12.3 Constructing the Security Panel Application
Date structure
Stores and displays date and time information
Property Now returns:
System time as a Date

24. 12.3 Constructing the Security Panel Application
Figure 12.12　Updating the Security Panel application’s ListBox.

25. 12.3 Constructing the Security Panel Application
Figure 12.13　Event handler btnZero_Click.
Appending “0” to the end of a String

26. 12.3 Constructing the Security Panel Application
Figure 12.14　Event handlers btnOne_Click and btnTwo_Click.
Appending “1” and “2” to the end of a String

27. 12.3 Constructing the Security Panel Application
Figure 12.15　Event handler btnClear_Click defined.
Clearing the TextBox

28. Using a Select Case statement to determine user access level
SecurityPanel.vb (1 of 5)
Declaring variables
Retrieving access code and clearing TextBox
Using a Select Case statement to determine user access level

29. SecurityPanel.vb (2 of 5)
Appending the numeric Button value to the text stored in the TextBox

30. SecurityPanel.vb (3 of 5)

31. SecurityPanel.vb (4 of 5)

32. SecurityPanel.vb (5 of 5)
Clearing the TextBox