Chapter 12: Using Controls

Transcription

1 Chapter 12: Using Controls

2 Using a LinkLabel LinkLabel Similar to a Label Provides the additional capability to link the user to other sources Such as Web pages or files Default event The method whose shell is automatically created when you double-click the Control The method you are most likely to alter with Control The event that users most likely expect to generate 2

3 Using a LinkLabel (cont d.) 3

4 Using a LinkLabel (cont d.) LinkLabel appears as underlined text The text is blue by default When you pass the mouse pointer over a LinkLabel, the pointer changes to a hand When a user clicks a LinkLabel, it generates a click event Executing a LinkClicked() method The LinkVisited property can be set to true when you determine that a user has clicked a link 4

5 Using a LinkLabel (cont d.) 5

6 Using a LinkLabel (cont d.) 6

7 Using a LinkLabel (cont d.) 7

8 Using CheckBox and RadioButton CheckBox objects Objects GUI widgets the user can click to select or deselect an option RadioButtons Similar to CheckBoxes Only one RadioButton in a group can be selected at a time 8

9 Using CheckBox and RadioButton Objects (cont d.) 9

10 Using CheckBox and RadioButton Objects (cont d.) 10

11 Using CheckBox and RadioButton Objects (cont d.) 11

12 Using CheckBox and RadioButton Objects (cont d.) 12

13 Using CheckBox and RadioButton Objects (cont d.) 13

14 Understanding GroupBoxes and Panels GroupBox or Panel Groups related Controls on a Form Can be anchored or docked inside a Form GroupBoxes Can display a caption Do not have scroll bars Panels Cannot display a caption Have scroll bars 14

15 GroupBoxes and Panels (Cont.) To create a GroupBox or Panel, drag its icon from the Toolbox onto a Form. Then, drag new controls from the Toolbox directly into the GroupBox or Panel. To enable the scrollbars, set the Panel s AutoScroll property to true. If the Panel cannot display all of its controls, scrollbars appear (Fig ) by Pearson Education, Inc. All Rights Reserved.

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17 NumericUpDown Control NumericUpDown Restrict a user s input choices to a specific range of numeric values. Appears as a TextBox, with two small Buttons on the right side NumericUpDown s ReadOnly property indicates if user can type a number into the control 17

18 NumericUpDown properties and event Description Common Properties Increment Maximum Minimum Specifies by how much the current number in the control changes when the user clicks the control s up and down arrows. Largest value in the control s range. Smallest value in the control s range. Value The numeric value currently displayed in the control. Common Event ValueChanged This event is raised when the value in the control is changed. This is the default event for the NumericUpDown control. NumericUpDown properties and event. 18

19 19 NumericUpDown Control

20 ToolTips A ToolTip component appears in the component tray the region below the Form in Design mode. A ToolTip on property for each ToolTip component appears in the Properties window for the Form s other controls. Figure demonstrates the ToolTip component by Pearson Education, Inc. All Rights Reserved.

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22 ToolTips (Cont.) Set the tool-tip text for the Labels to First Label and Second Label Figure shows the ToolTip in the component tray. We set the tool tip text for the first Label to "First Label" and the tool tip text for the second Label to "Second Label" by Pearson Education, Inc. All Rights Reserved.

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25 Adding a PictureBox to a Form PictureBox A Control in which you can display graphics from a bitmap, icon, JPEG, GIF, or other image file type 25

26 26

27 Adding a PictureBox to a Form (cont d.) 27

28 Adding a PictureBox to a Form (cont d.) 28

29 Adding ListBox, CheckedListBox, and ComboBox Controls to a Form ListBox, ComboBox, and CheckedListBox objects List-type widgets that descend from ListControl ListBox Control Displays a list of items the user can select by clicking Allows the user to make a single selection or multiple selections by setting the SelectionMode property SelectedItem property Contains the value of the item a user has selected 29

30 Adding ListBox, CheckedListBox, and ComboBox Controls to a Form (cont d.) 30

31 Adding ListBox, CheckedListBox, and ComboBox Controls to a Form (cont d.) 31

32 Adding ListBox, CheckedListBox, and ComboBox Controls to a Form (cont d.) 32

33 Adding ListBox, CheckedListBox, and ComboBox Controls to a Form (cont d.) 33

34 Adding ListBox, CheckedListBox, and ComboBox Controls to a Form (cont d.) 34

35 Adding ListBox, CheckedListBox, and ComboBox Controls to a Form (cont d.) ComboBox Control Similar to a ListBox Displays an additional editing field Allows the user to select from the list or to enter new text CheckedListBox Control Similar to a ListBox Check boxes appear to the left of each desired item 35

36 Adding ListBox, CheckedListBox, and ComboBox Controls to a Form (cont d.) 36

37 Adding MonthCalendar and DateTimePicker Controls to a Form MonthCalendar and DateTimePicker Controls Allow you to retrieve date and time information 37

38 Adding MonthCalendar and DateTimePicker Controls to a Form (cont d.) 38

39 Adding MonthCalendar and DateTimePicker Controls to a Form (cont d.) 39

40 Adding MonthCalendar and DateTimePicker Controls to a Form (cont d.) 40

41 Adding MonthCalendar and DateTimePicker Controls to a Form (cont d.) 41

42 Adding MonthCalendar and DateTimePicker Controls to a Form (cont d.) DateTimePicker Control Displays a month calendar when the down arrow is selected 42

43 Adding MonthCalendar and DateTimePicker Controls to a Form (cont d.) 43

44 Adding MonthCalendar and DateTimePicker Controls to a Form (cont d.) 44

45 Adding a MenuStrip to a Form Menu strip A horizontal list of general options that appears under the title bar of a Form or Window You can add a MenuStrip Control object to any Form you create When you double-click an entry in the MenuStrip, a Click() method is generated 45

46 Adding a MenuStrip to a Form (cont d.) 46

47 Adding a MenuStrip to a Form (cont d.) 47

48 Adding a MenuStrip to a Form (cont d.) 48

49 TreeView Control The TreeView control displays nodes hierarchically in a tree. A parent node contains child nodes, and the child nodes can be parents to other nodes. Two child nodes that have the same parent node are considered sibling nodes. The first parent node of a tree is the root node (a TreeView can have multiple roots) by Pearson Education, Inc. All Rights Reserved.

50 TreeView Control (Cont.) The nodes in a TreeView (Fig ) are instances of class TreeNode. Each TreeNode has a Nodes collection (type TreeNodeCollection), which contains a list of its children by Pearson Education, Inc. All Rights Reserved.

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52 TreeView Control (Cont.) To add nodes to the TreeView visually, click the ellipsis next to the Nodes property in the Properties window. This opens the TreeNode Editor (Fig ) by Pearson Education, Inc. All Rights Reserved.

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54 TreeView Control (Cont.) To add nodes programmatically, first create a root node. treeview1.nodes.add( ); To add children to a root node first select the appropriate root node: treeview1.selectednode To remove nodes programmatically, first select a node, then remove. treeview1.nodes.remove( ); by Pearson Education, Inc. All Rights Reserved.

55 TreeView Control (Example)

56 TabControl Control TabControls contain TabPage objects, which are similar to Panels. Add TabControls visually by dragging and dropping them onto a Form in Design mode. To add TabPages in Design mode, click the top of the TabControl, open its smart tasks menu and select Add Tab (Fig ). To select a TabPage, click the control area underneath the tabs by Pearson Education, Inc. All Rights Reserved.

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60 TabControl Example by Pearson Education, Inc. All Rights Reserved.

61 Multiple Document Interface (MDI) Many complex apps are multiple document interface (MDI) programs, which allow users to edit multiple documents at once. An MDI program s main window is called the parent window, and each window inside the app is referred to as a child window. Figure depicts a sample MDI app with two child windows. To create an MDI Form, create a new Form and set its IsMdiContainer property to true (Fig ) by Pearson Education, Inc. All Rights Reserved. Windows

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64 Multiple Document Interface (MDI) Windows (Cont.) Right click the project in the Solution Explorer, select Project > Add Windows Form and name the file. Set the Form s MdiParent property to the parent Form and call the child Form s Show method. Form2 childform = New Form2(); childform.mdiparent = this; childform.show(); by Pearson Education, Inc. All Rights Reserved.

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66 Multiple Document Interface (MDI) Windows (Cont.) Figure shows two images: one containing two minimized child windows and a second containing a maximized child window by Pearson Education, Inc. All Rights Reserved.

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