Controls I

1
Controls I
2
Hello World Program

• Make a TextBox to display Hello, world! when OK
  button is clicked.

3
Hello World Program(cont.)

• Enter the following code for command1_click()
• Text1.Text Hello, world!

4
Exercise

• Make a clear button to clean the TextBox.

5
Using File System Objects

• Browser Program
• A program that can display a picture file in the
  image object.
• A file can be selected by using
• DriverListBox,
• DirListBox, and
• FileListBox

6
The Format of Graphic Data

• bitmap .bmp
• Windows meta file .wmf
• icon .ico
• cursor .cur
• JPEG .jpg
• GIF .gif

7
Making a file selection object

• Make DriverListBox, DirListBox, and FileListBox,
  (see the next slide) and enter the following code
  for each objects
• Private Sub Drive1_Change()
• Dir1.Path Drive1.Drive set the drive of
  Dir1 to Drive1
• End Sub
• Private Sub Dir1_Change()
• File1.Path Dir1.Path set the directory of
  File1 to Dir1
• End Sub
• Private Sub File1_Click()
• SelectedFile File1.Path "\"
  File1.FileName
• Image1.Picture LoadPicture(SelectedFile)
• End Sub

8
Making a file selection object(cont.)
DriverListBox
DirListBox
FileListBox Pattern .bmp
Image Stretch True BorderStyle 1-????
9
Jargon

• Controls
• Tools in the toolbox to make objects on the forms
  of VB
• Objects
• User Interface elements on the VB forms
• Have inherent functionality like OOP
• Attributes
• Describes the property of each object
• Way to set attribute value
• object.property value

10
Jargon(cont.)

• Event procedures
• Procedures that are executed when some events
  related to the object occur
• ex) clicking of end button ? stopping the
  program
• Methods
• specific statements for a specific object
• format object.method input_value
• ex) List1.Additem Check

11
Check box

• Make a textbox with text1.text Division of
  Internet Engineering
• Make 2 checkBoxes
• And change the name of each checkBoxes
• from check1 to chk??
• And check2 to chk????
• add the code for each event procedure as in p66
  67

12
Option Buttons

• Can be used to select one among several choices
• Value attribute
• If the option button is selected, value TRUE
• You can group them using Frames
• Exercise
• Make 3 option buttons and 1 textBox like in p 69
• Use copy and paste function to make the 3 buttons
• Enter the code in p 69

13
Options buttons (cont)

• Frame can be used to group option buttons
• Exercise
• Make a form like fig 2.8 in p 69
• We should make the frame first
• Or we can use cut paste function
• Enter the code in p 70

14
Exercise

• Make a form that displays 2 questions asking
• What is your hobby?
• ? Reading ? Dancing ? Music listening
• What is your favorite car?
• ? Sonata ? Tico ? Avante
• (hint) Make two frames having 3 option boxes each

15
ListBox

• You can show a list of items by using a list box
• Important attributes
• ListIndex the index of user selected item
• List the data array for the list box
• Important method
• AddItem adds a new item in the list box

16
Exercise

• Make a form as in p 74
• Use
• Label
• Listbox
• commandButton
• Add the event procedures as in p 75
• Hint
• Use list attribute for the list values
• Use ctrlenter for continuous entering
• Use just enter to finish entering

17
addItem in the ListBox

• AddItem method can be used to enter initial
  values of the listbox
• Format list.AddItem item
• Exercise
• Make 4 labels and 1 listBox as in p 75, 76
• Use AddItem method to enter new values as in the
  middle of p 77
• For list1_click procedure, enter the code in p 76

18
Exercise

• Make 1 textbox, 1 listbox, and 3 buttons add,
  delete, end
• If add button is pressed, enlist the text in
  the textbox into the listbox
• If delete button is pressed, drop the item form
  the listbox
• Hint use the following attributes and method
• AddItem Text1.Text
• List1.RemoveItem (List1.ListIndex)

19
Combo Box

• Similar to ListBox but only one item can be seen
• Initial items can be given using the list
  attribute
• Enter the following as the list value Kim, Tom,
  Judy, Bob
• You can insert an item in the combo box
• After inserting an item, press enter key
• Exercise
• Make a form like p 81 (see the table in p 80 for
  values of attributes)
• Enter the code in p 81

20
Exercise

• Make a form that has one label, and two combo
  boxes, and one end button
• For the first combo box, enter the list as
  choices
• Tom, Bob, Jim, Tony, Brown
• For the second combo box, enter the list as
  choices
• Mary, Nancy, Kim, Betty, Lee
• If male or female is selected, display one of the
  following message in the label depending on
  gender
• Mr.XX is selected! where XX is one in the list
• Ms.XX is selected! where XX is one in the list