Visual Basic Controls

1. Visual Basic Controls

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. 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

6. 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”

7. Check box • Make a textbox with text1.text = “Division of Internet Engineering” • Make 2 checkBoxes, check1, check2 • Add the following code for each event procedure. Private Sub check1() If check1.value = vbChecked Then Text1.font.bold = True else Text1.font.bold = False End If End sub Private Sub check2() If check2.value = vbChecked Then Text1.font.Italic = True else Text1.font.Italic = False End If End sub

8. Option Buttons • Can be used to select one among several choices • Index attribute • If an option button is selected, index has appropriate value • You can group them using Frames • Exercise • Make 3 option buttons and 1 textBox. • Use copy and paste function to make the 3 buttons • Enter the following code. • Private Sub Option1_Click(Index As Integer) • If Index = 0 Then • Text1.Text = “Sonata Chosen” • elseif Index = 1 Then • Text1.Text = “Matiz Chosen” • else • Text1.Text = “Tico Chosen” • End If • End Sub

9. 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

10. 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

11. Exercise • Make a form as in p 74 • Use • Label (BorderStyle:1, Caption:List Index) • Listbox • commandButton • Hint: • Use ‘list’ attribute for the list values • Use ‘ctrl+enter’ for continuous entering • Use just ‘enter’ to finish entering • Add the following event procedures Private Sub List1_Click() Dim n, Name n = List1.ListIndex name = List1.List(n) Label1.Caption = “List Index:” & n & “ major ” & name End Sub Private Sub Command1_Click() Unload me End Sub

12. addItem in the ListBox • AddItem method can be used to enter initial values of the listbox • Format: list.AddItem “item” • Exercise • Make the same form as in the previous slide. • Use AddItem method to enter new values. Private Sub Form_load() List1.Additem “Computer & Internet Eng.” List1.Additem “Multimedia Eng.” List1.Additem “Information Network Eng.” List1.Additem “Electrical Eng.” List1.Additem “Industrial Eng.” End Sub

13. 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 methods for ‘add’ and ‘delete’ respectively. • AddItem Text1.Text • List1.RemoveItem (List1.ListIndex)

14. Combo Box • Similar to ListBox but only one item can be seen • Initial items can be given using the list attribute • Enter ‘Kim, Tom, Judy, Bob’ as value of attribute ‘List’ • Enter ‘Choose One’ as value of attribute ‘Text’ • You can insert an item in the combo box • After inserting an item, press ‘enter’ key • Exercise • Make a form like the above • Enter the following code. Private Sub Combo1_Click() Label1.Caption = Combo1.Text & " has been chosen." End Sub • Private Sub Command1_Click() • End • End Sub

15. 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