Mastering Windows Forms for Event-Driven GUIs

1. CSCI 3328 Object Oriented Programming in C# Chapter 10: Graphical User Interfaces with Windows Forms Xiang Lian The University of Texas – Pan American Edinburg, TX 78539 lianx@utpa.edu

2. Objectives • In this chapter, you will • Learn how to process events that are generated by user interface controls and event handling • Know how to create and use Button, Label, RadioButton, CheckBox, TextBox, Panel and NumbericUpDown controls • Know how to add ToolTips to GUI controls • Discover how to process mouse and keyboard events • Become familiar with more controls, such as Menus, tabbed windows, and multiple document interface (MDI), ListView, TreeView, LinkLabel, ListBox, ComboBox, DateTimePicker

3. Windows Forms • Dialog • MDI (window multiple document Interface) Window • Controls and components are placed on the form • Toolbox allows you to choose controls and components • A form is a container that holds the controls and components

4. Controls

5. Event Handling • Events drive the program to perform a task • Click • Change • Time • Event handler is what you write

6. Example of Event-Driven GUI • Click event of Button private void clickButton_Click(object sender, EventArgs e) { MessageBox.Show("Button was clicked"); }

7. Visual Studio Generated Code • Can give great insight into what is going on • See what is in the Designer.cs • It will have all controls and components you placed there

8. Integrated Development Environment • Events events Properties window

9. Creating Event Handlers • Double click on a control and write code • Known as default event • You can use the properties window to create event handlers • Click on the events (looks like the lightning) in the properties window

10. Control Properties and Layout • Controls derive from class Control • Common control properties • BackColor • BackgroundImage • Enabled • Focused • Font • ForeColor • TabIndex • Text • Visible • Common methods • Hide • Select • Show

11. Anchor Property • Anchoring causes controls to remain at a fixed distance from the sides of the container, even when the container is resized • Darkened bar indicate the container’s sides to which the control is anchored

12. Dock Property and Other Properties • Dock • Other properties • Location • Size • MaximumSize • MinimumSize

13. Labels, TextBoxes and Buttons • A Label displays text that the user cannot directly modify • A TextBox is an area in which either text can be displayed by a program or user can type text via keyboard • A password TextBox • Set UseSystemPasswordChar to true • A Button is a control that the user clicks to trigger a specific action or to select an option in a program

14. Common Properties/Events of Labels, TextBoxes and Buttons • Label • Font, Text, TextAlign • TextBox • AcceptReturn • If true in a multiline TextBox, pressing Enter in the TextBox creates a new line • Multiline, ReadOnly, ScrollBars, Text, UseSystemPasswordChar • Event: TextChanged • Button • Text, FlatStyle • Event: Click

15. GroupBoxes and Panels • GroupBoxes and Panels arrange controls on a GUI • All controls in a GroupBox or Panel move together when the GroupBox or Panel is moved • Properties of GroupBoxes • Controls • Text • Properties of Panels • AutoScroll (when resizing panels) • BorderStyle • Controls

16. CheckBoxes and RadioButtons • CheckBoxes • Appearance, Checked, CheckState, Text • ThreeState • Checked, unchecked, and indeterminate (grey color; can be set programmatically) • Event: CheckedChanged, CheckStateChanged • RadioButtons • Checked, Text • Event: CheckedChanged

17. Example of CheckBoxes and RadioButtons private void boldCheckBox_CheckedChanged(object sender, EventArgs e) { outputLabel.Font = new Font(outputLabel.Font, outputLabel.Font.Style ^FontStyle.Bold); } ------------------------------------------------------------------------------------- private MessageBoxButtons buttonType; private void buttonType_CheckedChanged(object sender, EventArgs e) { if (sender == okRadioButton) buttonType = MessageBoxButtons.OK; } name of a radio button

18. PictureBox • Properties • Image • SizeMode • Events • Click • Example of setting image resources • imagePictureBox.Image=(Image) (Properties.Resources.ResourceManager.GetObject("image1");

19. ToolTips • Drag ToolTip to the form • Then each control has a new property "ToolTip on toolTip1" • Properties • AutoPopDelay • The amount of time that the tool tip appears while the mouse is over a control • InitialDelay • The amount of time that a mouse must hover over a control before a tool tip appears • ReshowDelay: • The amount of time between which two different tool tips appear • Load Method of the form • tooltip1.SetToolTip(this.button1, "tips here"); • Event • Draw

20. NumericUpDown Control • Properties • DecimalPlaces • Increment • Maximum • Minmum • UpDownAlign • Value • Event • ValueChanged

21. Mouse Handling private void PainterForm_MouseDown(object sender, MouseEventArgs e) { shouldPaint = true; } private void PainterForm_MouseUp(object sender, MouseEventArgs e) { shouldPaint = false; } private void PainterForm_MouseMove(object sender, MouseEventArgs e) { if (shouldPaint) { Graphics graphics = CreateGraphics(); graphics.FillEllipse(new SolidBrush(Color.BlueViolet), e.X, e.Y, 4, 4); graphics.Dispose(); //dispose of resources } } Location of the mouse

22. Mouse Handling (cont'd) • Event EventArgs • MouseEnter • MouseLeave • Event MouseEventArgs • MouseDown • MouseHover • MouseMove • MouseUp • Properties of class MouseEventArgs • Button (Left, Right, Middle or none button of the mouse) • Clicks (number of clicking times) • X • Y

23. Keyboard Events • Event KeyEventArgs • KeyDown • KeyUp • Event KeyPressEventArgs • KeyPress • Properties of class KeyPressEventArgs • KeyChar • Handled (whether the event was handled) • Properties of class KeyEventArgs • Alt (whether Alt key was pressed) • Control (whether Ctrl key was pressed) • Shift (whether Shift key was pressed) • Handled (whether the event was handled)

24. Menus • Main menu bar • Type menu name • Place & character before a letter to underline it • E.g., &File • Effect: File (you can press Alt+F keys to select file menu) • Select shortcut keys for menu items • You can remove a menu item by selecting it with mouse and pressing Delete key

25. Menus (cont'd) • Options of menu items • Right click a menu item • ToolStripMenuItem • ComboBox • Separator • TextBox

26. Menus (cont'd) • MenuStrip Properties • HasChildren • RightToLeft • ToolStripMenuItem Properties • Checked • CheckOnClick • Index • MenuItems • ToolStripMenuItem Event • Click

27. Example of Menus • Checked Property • blackToolStripMenuItem.Checked = true; • Event private void blackToolStripMenuItem_Click(object sender, EventArgs e) { displayLabel.ForeColor = Color.Black; blackToolStripMenuItem.Checked = true; }

28. MonthCalendar Control • Properties • FirstDayOfWeek • MaxDate • MaxSelectionCount • Maxixmum number of dates that can be selected at once • MinDate • MonthlyBoldedDates • An array of dates that will be displayed in bold in the calendar • SelectionEnd • SelectionRange • SelectionStart • Event • DateChanged

29. DateTimePicker Control • Properties • CalendarForeColor • CalendarMonthBackground • CustomFormat • Date • Format • MaxDate • MinDate • ShowCheckBox • ShowUpDown • TimeOfDay • Value • Event • ValueChanged

30. Example of DateTimePicker private void dateTimePickerDropOff_ValueChanged(object sender, EventArgs e) { DateTime dropOffDate = dateTimePickerDropOff.Value; if (dropOffDate.DayOfWeek == DayOfWeek.Friday || dropOffDate.DayOfWeek == DayOfWeek.Saturday || dropOffDate.DayOfWeek == DayOfWeek.Sunday) outputLabel.Text = dropOffDate.Add(3).ToLongDateString(); else outputLabel.Text = dropOffDate.Add(2).ToLongDateString(); }

31. LinkLabel Control • Properties • LinkVisited • If true, the link appears as though it has been visited • LinkColor • Text • VisitedLinkColor • Event • LinkClicked • System.Diagnostics.Process.Start(@"C:\"); • System.Diagnostics.Process.Start("http://faculty.utpa.edu/lianx"); • System.Diagnostics.Process.Start("notepad");

32. ListBox Control • Properties of ListBox • SelectionMode • MultiColumn • SelectedIndex • If no items are selected, SelectedIndex = 1 • SelectedIndices • For multiple selected items • SelectedItem • SelectedItems • Sorted • Indicate whether items are sorted alphabetically • Methods of ListBox • ClearSelected • GetSelected(index) • Return true, if the corresponding item is selected • Event of List Box • SelectedIndexChanged

33. Example of ListBox Control • myListBox.Items.Add(myListItem); • CheckedListBox Control • Inherit from ListBox

34. ComboBox Control • Properties • DropDownStyle • Items • MaxDropDownItems • SelectedIndex • SelectedItem • Sorted • Event • SelectedIndexChanged

35. Other Controls • TreeView Control • "Nodes" property • Add root, or add child • AfterSelect event • When selected node changes

36. Other Controls (cont'd) • TabControl Control • Contains TabPage objects which are similar to Panels and GroupBoxes • myTabPage.Controls.Add(myControl); • myTabPage.Controls.Add(myTabPage); • Properties • ImageList • ItemSize • Tab size • Multiline • SelectedIndex • SelectedTab • TabCount • TabPages • Add more tabs • Event • SelectedIndexChanged