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How to: Define Control Access and Values (C++)

  • Artikkeli

Tab Order

The tab order is the order in which the Tab key moves the input focus from one control to the next within a dialog box. Usually the tab order proceeds from left to right and from top to bottom in a dialog box. Each control has a Tabstop property that determines whether a control receives input focus.

  • To set input focus for a control, in the Properties Window, select True or False in the Tabstop property.

Even controls that don't have the Tabstop property set to True need to be part of the tab order, especially for controls that don't have captions. Static text that contains an access key for a related control must immediately precede the related control in the tab order.

Note

If your dialog box contains overlapping controls, changing the tab order may change the way the controls are displayed. Controls that come later in the tab order are always displayed on top of any overlapping controls that precede them in the tab order.

  • To view the current tab order for all controls, go to menu Format > Tab Order, or press Ctrl + D.

    A number in the upper-left corner of each control shows its place in the current tab order.

  • To change the tab order for all controls, go to menu Format > Tab Order and set the tab order by selecting each control in the order you want the Tab key to follow.

  • To change the tab order for two or more controls, go to menu Format > Tab Order. Hold down the Ctrl key and select the control where the change in order will begin, then release the Ctrl key and select the controls in the order you want the Tab key to follow from that point.

    For example, if you want to change the order of controls 7 through 9, hold down Ctrl, then select control 6 first.

  • To set a specific control to number 1, or first in the tab order, double-click the control.

Tip

Once you enter Tab Order mode, press Esc or Enter to exit Tab Order mode and disable the ability to change the tab order.

Mnemonics (Access Keys)

Normally, keyboard users move the input focus from one control to another in a dialog box with the Tab and Arrow keys. However, you can define an access key (a mnemonic or easy-to-remember name) that allows users to choose a control by pressing a single key.

To define an access key for a control with a visible caption (push buttons, check boxes, and radio buttons)

  1. Select the control on the dialog box.

  2. In the Properties Window, in the Caption property, type a new name for the control, typing an ampersand (&) in front of the letter you want as the access key for that control. For example, &Radio1.

  3. Press Enter.

    An underline appears in the displayed caption to indicate the access key, for example, Radio1.

To define an access key for a control without a visible caption

  1. Make a caption for the control by using a Static Text control in the Toolbox.

  2. In the static text caption, type an ampersand (&) in front of the letter you want as the access key.

  3. Make sure the static text control immediately precedes the control it labels in the tab order.

Note

All access keys within a dialog box should be unique. To check for duplicate access keys, go to menu Format > Check Mnemonics.

Combo Box Values

You can add values to a combo box control as long as you have the Dialog Editor open.

Tip

It's a good idea to add all values to the combo box before you size the box in the Dialog Editor, or you may truncate text that should appear in the combo control.

To enter values into a combo box control

  1. Choose the combo box control by selecting it.

  2. In the Properties Window, scroll down to the Data property.

    Note

    If you're displaying properties grouped by type, Data appears in the Misc properties.

  3. Select the value area for the Data property and type in your data values, separated by semicolons.

    Note

    Don't put spaces between values because spaces interfere with alphabetizing in the drop-down list.

  4. Press Enter when you are finished adding values.

For information on enlarging the drop-down portion of a combo box, see Setting the Size of the Combo Box and Its Drop-Down List.

Note

You can't add values to Win32 projects using this procedure (the Data property is grayed out for Win32 projects). Because Win32 projects do not have libraries that add this capability, you must add values to a combo box with a Win32 project programmatically.

To test the appearance of values in a combo box

  1. After entering values in the Data property, select the Test button on the Dialog Editor Toolbar.

  2. Try scrolling down the entire value list. Values appear exactly as they are typed in the Data property in the Properties window. There is no spelling or capitalization checking.

  3. Press Esc to return to the Dialog box editor.

Radio Button Values

When you add radio buttons to a dialog box, treat them as a group by setting a Group property in the Properties window for the first button in the group. A control ID for that radio button then appears in the Add Member Variable Wizard, allowing you to add a member variable for the group of radio buttons.

You can have more than one group of radio buttons on a dialog box. Add each group using the following procedure.

To add a group of radio buttons to a dialog box

  1. Select the radio button control in the Toolbox Window and choose the location in the dialog box where to place the control.

  2. Repeat the above step to add as many radio buttons as you need. Make sure the radio buttons in the group are consecutive in the tab order.

  3. In the Properties Window, set the Group property of the first radio button in the tab order to True.

    Changing the Group property to True adds the WS_GROUP style to the button's entry in the dialog object of the resource script and prevents the user can from selecting more than one radio button at a time in the button group (if the user selects one radio button, the others in the group are cleared).

    Note

    Only the first radio button in the group should have the Group property set to True. If you have additional controls that aren't part of the button group, set the Group property of the first control that is outside the group to True as well. You can quickly identify the first control outside of the group by using Ctrl+D to view the tab order.

To add a member variable for the radio button group

  1. Right-click the first radio button control in the tab order (the dominant control and the one with the Group property set to True) and choose Add Variable.

  2. In the Add Member Variable wizard, select the Control variable check box, then select the Value radio button.

    • In the Variable name box, type a name for the new member variable.

    • In the Variable type list box, select int or type int.

    You can now modify your code to specify which radio button should appear selected. For example, m_radioBox1 = 0; selects the first radio button in the group.

Requirements

Win32

See also

Manage Dialog Box Controls
How To: Add, Edit, or Delete Controls
How To: Layout Controls