UTPA – Fall 2011

1. CSCI 3327 Visual Basic Chapter 10: Windows Forms GUI: A Deeper Look UTPA – Fall 2011

2. Objectives • In this chapter, you will • Learn the design of graphical user interfaces (GUIs) • Get familiar with programming mouse and keyboard events • Know how to create and manipulate controls • E.g., Panel, ToolTip, Menu, MonthCalendar, LinkLabel, and CheckedListBox,

3. Controls

4. Controls and Components • ToolBox • A form is a container for controls and components • Visual Studio generates code of controls and components when you drag them onto the form

5. Common Properties of a Form • AcceptButton • Button that is clicked when Enter key is pressed • AutoScroll • CancelButton • Button that is clicked when Esc key is pressed • FormBorderStyle • Font • Text

6. Common Methods & Events of a Form • Methods • Close • Close a form and release its resources • Hide • Hide a form without releasing or destroying its resources • Show • Display a hidden form • Events • Load

7. Create Event Handlers • In the code editor window • Select a control (e.g. button) from the left combo box • Select an event from the right combo box • Code is generated automatically

8. Control Properties and Methods • Properties • TabIndex • Controls receive focus in the order of TabIndex property • TabStop • Prevent the control from receiving the focus in this manner • Enabled vs. Visible • Methods • Focus • Hide: set Visible property to False • Show: set Visible property to True

9. GroupBoxes and Panels • Properties of GroupBox • Controls • Text • Properties of Panel • AutoScroll • BorderStyle • Controls

10. Example 14.12: PanelDemo.vb • URL: • http://media.pearsoncmg.com/ph/esm/deitel/vb_htp_2010/codeexamples.html • Display the button you clicked on Panel • Hanldes Button1.Click, Button2.Click • The same method for multiple events • Ctype (sender, Button).Text

11. Tool Tips • A helpful text that appears when the mouse hovers over a GUI control • Drag ToolTip component to form • It appears below the form in the design mode • Each control will have an extra property • ToolTip on ToolTip1

12. Mouse-Event Handling • Mouse events • Clicks, presses, and moves • For most mouse events, information about the event is passed to the event-handling method by an object of class MouseEventArgs • Mouse pointer's x- and y-coordinates • The mouse button pressed (Right, Left or Middle) • The number of times the mouse was clicked

13. Mouse-Event Handling (cont'd) • Mouse events • Mouse event with event argument of type EventArgs • MouseEnter, MouseLeave • Mouse event with event argument of type MouseEventArgs • MouseDown, MouseHover, MouseMove, MouseUp • Class MouseEventArgs properties • Button, Clicks, X, Y

14. Example 14.18: Painter.vb • URL: • http://media.pearsoncmg.com/ph/esm/deitel/vb_htp_2010/codeexamples.html • Painter_MouseMove • e As MouseEventArgs • e.X, e.Y • g As Graphics = CreateGraphics() • G.FillEllipse(New SolidBrush(Color.BlueViolet), e.X, e.Y, 4, 4) 4 (e.X, e.Y) 4

15. Keyboard-Event Handling • Key Events with Event Arguments of Type KeyEventArgs • KeyDown, KeyUp • Key Events with Event Arguments of Type KeyPressEventArgs • KeyPress • Class KeyPressEventArgs properties • KeyChar (ASCII character for the key pressed) • Handled (indicating wether the KeyPress event was handled) • Class KeyEventArgs properties • Alt, Control, Shift, Handled, KeyCode

16. Example 14.20: KeyDemo • URL: • http://media.pearsoncmg.com/ph/esm/deitel/vb_htp_2010/codeexamples.html • ByVal e As KeyPressEventArgs • e.KeyChar • ByVal e As KeyEventArgs • e.Alt, e.Shift, e.Control • e.KeyCode.ToString(), e.KeyData.ToString(), e.KeyValue.ToString()

17. Menu • Menu • Shortcut Keys • Type an ampersand (&) symbol before the character to be underlined • To display &, use && • To add shortcut keys for menu items • Set the ShortcutKeys property • Other types of menu items • Separator bar • ComboBox • MenuItem • TextBox

18. Example 14.25: MenuTest.vb • URL: • http://media.pearsoncmg.com/ph/esm/deitel/vb_htp_2010/codeexamples.html • blackToolStripMenuItem.Checked = True • displayLabel.Font = New Font("Times New Roman", 14, displayLabel.Font.Style) • Application.Exit()

19. MonthCalendar Control • Properties • FirstDayOfWeek • MaxDate, MinDate • MaxSelectionCount • SelectionRange • Event • DateChanged

20. Example 14.29: DateTimePicker • URL: • http://media.pearsoncmg.com/ph/esm/deitel/vb_htp_2010/codeexamples.html • dropOffDateTimePicker.MinDate=DateTime.Today • dropOffDateTimePicker.MaxDate=DateTime.Today.AddYears(1) • Dim dropOffDate As DateTime = dropOffDateTimePicker.Value • dropOffDate.DayOfWeek=DayOfWeek.Friday • dropOffDate.AddDays(3).ToLongDateString()

21. LinkLabel Control • Display links to other resources • Example 14.31: • URL:http://media.pearsoncmg.com/ph/esm/deitel/vb_htp_2010/codeexamples.html • cDriveLinkLabel.LinkClicked • cDriveLinkLabel.LinkVisited = True • Process.Start(“C:\”) • Process.Start(“http://www.deitel.com”) • Process.Start(“notepad”)

22. Process.Start(" ") • Effect of Process.Start(" ") • Start  Run • cmd • calc • notepad

23. ListBox and CheckedListBox Controls • ListBox properties • MultiColumn • SelectedIndex • -1 – no items are selected • If multiple items are selected, one of selected indices is returned • SelectedIndices • For multiple selected items • SelectedItem, SelectedItems • SelectionMode: None, One, MultiSimple, MultiExtended • Sorted: alphabetically, False by default

24. ListBox and CheckedListBox Controls (cont'd) • ListBox methods • ClearSelected • GetSelected • Take an index as an argument, and return True if the corresponding item is selected • myListBox.Items.Add(myListItem) • ListBox Events • SelectedIndexChanged

25. ListBox and CheckedListBox Controls (cont'd) • CheckedListBox properties • CheckedItems • A collection of items that are checked • CheckedIndices • A collection of indices for all checked items • CheckOnClick • False by Default • SelectionMode • Determine how many items can be checked: One or None

26. ListBox and CheckedListBox Controls (cont'd) • CheckedListBox Method • GetItemChecked • Take an index and returns True if the corresponding items is checked • CheckedListBox Event • ItemCheck • ItemCheckEventArgs • CurrentValue • Index • NewValue

27. Example 14.35: CheckedListBoxTest.vb • URL: • http://media.pearsoncmg.com/ph/esm/deitel/vb_htp_2010/codeexamples.html • itemCheckedListBox.SelectedItem.ToString() • If e.NewValue = CheckState.Checked

28. Multiple Document Interface (MDI) Windows • Single document interface (SDI) vs. multiple document interface (MDI) • MDI: Parent and child windows MDI child MDI child MDI parent

29. Multiple Document Interface (MDI) Windows (cont'd) • Specify a form is an MDI container • Set IsMdiContainer property to True • Create a class for child forms • Solution Explorer  Add  Windows Form… • Create a new child form • Set MdiParent property to the parent form • Call the child form’s Show method

30. Multiple Document Interface (MDI) Windows (cont'd) • MDI container features • MdiChildren property • Return an array of child Form references • ActiveMdiChild property • Return a reference to the active child window • Tracking child windows in menus • MenuStrip class provides property MdiWindowListItem • To check which child windows are open in an MDI container

31. Multiple Document Interface (MDI) Windows (cont'd) • Arrange child windows • Parent form has method LayoutMdi • Tiled windows (value TileHorizontal or TileVertical) • Cascaded windows (value Cascade)

32. Example 14.42: UsingMDI.vb • URL: • http://media.pearsoncmg.com/ph/esm/deitel/vb_htp_2010/codeexamples.html • Dim child = new ChildForm(“XXX”, “vb2008htp") • child.MdiParent = Me • child.Show() • Me.LayoutMdi(MdiLayout.Cascade) • Me.LayoutMdi(MdiLayout.TileHorizontal) • Me.LayoutMdi(MdiLayout.TileVertical)

33. Animation with the Timer Component • Timer component generates Tick events at fixed time interval • Timer component has Interval property • The number of milliseconds between events • By default, timers are disabled • Set Enabled property to True

34. Example 14.47: AnimationDemo.vb • URL: • http://media.pearsoncmg.com/ph/esm/deitel/vb_htp_2010/codeexamples.html • Display a new image every 50 milliseconds • Handles animationTimer.Tick