1. CS 106 Computing Fundamentals II Chapter 35 “Controls For Choices”
Herbert G. Mayer, PSU CS
Status 7/17/2013
Initial content copied verbatim from
CS 106 material developed by
CS professors: Cynthia Brown & Robert Martin

2. Syllabus Controls For Choices Option Button Creating Option Buttons
About the Demo
Events

3. Controls for Choices
Let’s look at new controls: option buttons and check boxes
These controls are designed to be used when you want the user of the program to have choices
We’ll use conditionals to determine which values have been set and have the program act accordingly

4. Option Buttons
Option buttons come in groups, but only one button in the group can be selected
We use the prefix opt for this control. Let’s say there are three buttons in a group for choosing a size, Small, Medium, or Large
We can name our buttons optSmall, optMedium, and optLarge

5. Creating Option Buttons
Generally start with a frame!! Then place Option Buttons into the frame; such as:
Choose the Option Button tool in the Toolbox and create as many as you want in a group
Name the buttons and change their text
Notice that the buttons are round
You are now ready to use them in a program

6. Check Boxes
Check boxes are similar to option buttons but more than one in a group can be checked
While option buttons make sense for choosing something like model or color, check boxes can be used for choosing something like features, where more than one can be chosen (AC, disk brakes, super sound package, leather seats, fancy wheels, etc.)

7. Creating Check Boxes
It’s the same procedure as for option buttons, but the frame is optional
Yet if you pick a frame, create it first
The logic of the associated conditional will be different since more than one can be checked
We’ll use the prefix chk for these named control

8. OptionDemo: If statements, check boxes, option buttons, demonstrated by showing HW3

9. About the Demo
Check if an option -or check box- Value is True to see if it is selected: If chkTaller.Value Then btnPush.Height = btnPush.Height * 2 End If ‘ sometimes programmers code: If chkTaller.Value = True Then

10. Events
Checking a box or selecting a button is an event. But if there is no code for an event, nothing happens
There is no code for the event of selecting the red, blue, and green buttons. In HW3, their values are checked during the btnPush click event