More Controls and Their Properties

1
More Controls and Their Properties

• Part 4 dbg --- TextBox, CheckBox, RadioButton,
  GroupBox, ToolTips,

2
Buttons (Review)

• Buttons allow user to choose when they are ready
  to perform an action.
• Each Button should be given a meaningful name
  that begins with btn.
• Text that will appear on the Button itself is
  typed in the Text Property of the Button.
• The code that should execute when a button is
  clicked, will go in the Click event handler.

3
Special Buttons

• One button can be designated as the AcceptButton
  Property value for the form. That particular
  button will be automatically clicked when you
  press the Enter key if the button has focus.
• One button can be designated as the CancelButton
  Property for the form. That particular button
  will be automatically clicked when you press
  the Esc key if the button has focus.

4
Labels (Review)

• Labels are be used for output only.
• Keep the default names (Label1, Label2, etc.) for
  labels that act as headings or static messages.
• Rename labels whose appearance will change at
  runtime use lbl prefix for labels that you
  rename.
• Set the design time contents of a label by typing
  a Text Property value in the Property Window
  alignment of this text can be set by clicking on
  the desired TextAlign Property.

5
Control Formatting

• Set a different color for text by setting the
  ForeColor Property.
• Set a different size or style with the Font
  Property.
• Set a different background color by setting the
  BackColor Property.
• Should a label have an outline or not? Set the
  BorderStyle Property
• None (default)
• FixedSingle (use this to designate that output
  will be displayed at runtime)
• Fixed3D (will look like a TextBox)

6
Drawing a Line via a Label

• Put a label control onto the form at the desired
  location.
• Set the Text Property to blank/empty.
• Set the BackColor Property to the desired line
  color.
• Set the BorderStyle Property to None.
• Set the size of the line by setting the Width and
  Height of the Size Property.

7
How to Select and Work with Multiple Controls

• Ways to select multiple controls
• Position mouse to left of a control, depress the
  left mouse button, and drag to outside/right of
  last control this is called lassoing.
• -or-
• Click a control, press Shift or Ctrl and continue
  clicking additional controls until you have
  selected all desired controls.
• Click 1 control to make it the primary control
  it will display with white handles. You can
  align, size, or format all of the selected
  controls by sizing, aligning, and/or formatting
  the primary control.

8
Formatting Multiple Controls at one Time

• Highlight multiple controls.
• Format using tools
• -or-
• Format using menus
• Choose Format, Make Same Size to make several
  controls the same size.
• Choose Format, Align to line up controls.
• Choose Format, Horizontal Spacing or Vertical
  Spacing to change spacing.

9
Lets Work on Diner Specials Again

• Move button controls and results label down a
  little on form. Size, align, and adjust spacing
  as necessary.
• Draw a line between diner name and buttons.
• Change the color and size of the results label
  text and diner name label text.
• Display an outline around results label.
• Set a button as AcceptButton Property for form.

10
Text with TextBoxes

• TextBox controls can display text like Label
  controls.
• But more importantly, TextBox controls also allow
  the user to input/modify the text at run time.
• Name TextBoxes with the txt prefix.

11
Assign Text at Design Time

• As with the Label control, the Text Property of
  the TextBox control may be assigned using the
  Property Window at design time.

? TextBoxTextDesignTime
12
Text Modification by User at Run Time

• The TextBox Text Property is modifiable by the
  user at run time. Information typed by the user
  may then be used by the program.
• It is important to note that anything typed in a
  TextBox (even numbers) will be considered a
  string and will have to be converted to
  numeric data type before use. More later
• In the example below, TextBox input is used to
  change the Text Property of the form, when a
  Button is clicked.

? UserChangeFormText
13
Modifying Access to a Control

• We can set the ReadOnly Property of a TextBox to
  True allowing display of output only no input
  will be allowed.
• We can set the Enabled Property of any control to
  False the control is dimmed at run time, but
  still visible.
• We can set the Visible Property of any control to
  False the control will be invisible at run time.

? ChangeAccess
14
CheckBox

• A CheckBox control is appropriate for portraying
  one, or a series of independent binary (on/off)
  decisions.
• Clicking a CheckBox toggles its Checked Property
  between True and False.
• A CheckBox control is completely independent from
  any other CheckBox.
• CheckBox controls should be named with a chk
  prefix.

15
CheckBox

• The Text Property of a CheckBox is displayed
  adjacent to the actual check box of the control,
• The Checked Property is a Boolean value (True or
  False) that may be evaluated at run time.

? CheckBox1
? CheckBox2
16
CheckedChanged Event

• The CheckBox control raises the CheckedChanged
  Event when it is either checked or unchecked.
• This event can often streamline coding and design
  of interfaces using CheckBox controls.

? CheckedChanged
17
RadioButton

• Like their namesakes, RadioButton controls are
  meant to be used in groups where only one may be
  checked at a time.
• RadioButtons should be used to portray decisions
  with exclusive resultsonly one option is allowed
  among several possibilities.
• Each RadioButton control should be named with a
  rad prefix.

18
RadioButton

• Setting the Checked Property of one RadioButton
  to True automatically sets the Checked Properties
  of all other RadioButtons in the set to False.
• Only one set of RadioButtons may be created
  directly on a form.

? RadioButton2
? RadioButton1
19
Containers for RadioButtons

• If we want to use more than one set of
  RadioButtons on a form, we have to isolate each
  set in a container control on the form.
• The GroupBox and Panel controls can isolate sets
  of RadioButtons on a form.
• Name a GroupBox control with a grp prefix.
• Name a Panel control with a pnl prefix.
• Add a GroupBox or Panel control to your form
  first and then add the grouped controls to the
  GroupBox or Panel container.

20
GroupBox

• The GroupBox control is especially designed to
  function as a container.
• The border appearance is not adjustable.
• Type a caption/title for a GroupBox in the Text
  Property.
• GroupBoxes are a bit like miniature forms
  however, they are unable to raise any mouse
  events except the MouseHover.

21
GroupBox

• It is possible to set a background image and draw
  on a GroupBox, but normally its use is limited to
  containing controls in logical or functional
  groups.
• Setting the Visible Property of a GroupBox
  affects the contained controls.

? RadioButtonGroup
22
Picture Box

• A PictureBox control can hold an image (graphic
  file with .jpg, .gif, .bmp, or .ico extension).
• For now, we will make our PictureBox controls
  square in size. Name PictureBox controls using a
  pic prefix.
• I have posted icons.zip on my website which
  contains icons provided with VS 2003.
• You should copy any image files that you use
  into the Bin folder of your project before using.
• Then set the Image Property of the PictureBox to
  the filename of the graphic image.

23
PictureBox Properties

• Icon (.ico) files are generally square in size,
  which will match the shape of our PictureBox.
• Other image files will most likely have different
  Height and Width Properties and resizing can
  result in distortion. Well learn how to deal
  with that later.
• For our purposes now, we will set the SizeMode
  Property of a PictureBox to StretchImage, which
  will automatically resize the graphic to fit the
  size of our PictureBox control.

24
Empty Text Property of Labels and Textboxes

• At design time, the Text Property can be
  cleared/deleted using Delete key.
• At run time, the Text Property of labels and
  textboxes can be set to an empty string.
• lblCost.Text
• For textboxes only, you can use the Clear()
  method to empty a textbox.

25
Lengthy Text in Labels or TextBoxes

• A lengthy Text Property value may not fit on one
  line of code in an event handler function.
• lblMessage.Text I live at\n12345 Grand
• Boulevard\nSchenectady, NY
• 12306-3456
• Match up double quotes on each line.
• \n (within a string literal) can be used to
  force a carriage return.
• is used to concatenate strings.

26
Adding Access (Hot) Keys

• Access keys (hot keys) allow users to select
  controls using the keyboard rather than the
  mouse.
• Access keys (hot keys) are created by inserting
  an character ahead of the character (that will
  act as a hot key) in the Text Property of a
  control.
• The user presses Alt and the appropriate hot key
  to select a particular control without using the
  mouse.

Note You may need to customize your computer to
display hot keys. Right-click an open area of
Desktop. Choose Properties in context menu. Click
Appearance Tab. Click Effects button. If
necessary, uncheck box that says Hide underlined
letters for keyboard navigation until I press the
Alt key.
27
More Access Keys (Hot Keys)

• When you set access keys (hot keys), make sure to
  use a unique letter for each control.
• Since the access keys aren't case sensitive, N
  and n set the same access key.
• You cant set an access key for a textbox.
  However, if you set an access key for the label
  immediately precedes the textbox in the tab
  order, the access key will take the user to the
  textbox.

28
Tab Order

• Tab order refers to the sequence in which the
  controls receive the focus when the user presses
  the Tab key.
• Most controls have a TabStop Property and a
  TabIndex Property.
• If the TabStop Property is set to True, focus can
  be directed to the control via the Tab key.
  (Labels dont have a Tabstop Property so they
  cant receive the focus.)
• The TabIndex Property indicates the controls
  position in tab order.

29
Viewing Tab Order

• The TabIndex Property can be set for each control
  via the Properties Window.
• Alternatively, you can set the tab order for the
  entire form by choosing View, Tab Order in the
  menu. Click the controls in the order you wish
  them to receive focus.

? ViewTabOrder
30
ToolTips

• ToolTips are message strings that pop into view
  when the mouse pointer hovers over an object with
  which they are associated.
• First add the ToolTip provider to a form. It will
  be named toolTip1 and will be in the component
  tray below the form. A ToolTip on toolTip1
  Property is automatically added to the form and
  all controls.
• Next type helpful text in the ToolTip on toolTip1
  Property for the form and controls.

? Diner Specials with ToolTips
31
Lets Do a Problem Together

• Create a project to display the flag of one of 4
  different countries, depending on the setting of
  the radio buttons. In addition, display the name
  of the country in a large label under the flag
  image. The user can also choose to display or
  hide the forms title bar text, the country name,
  and the name of the programmer. Use check boxes
  for the display/hide choices. Include keyboard
  access keys for all radio buttons, check boxes,
  and buttons. Make the Exit button the Cancel
  button. Include Tooltips.