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# QCheckBox Class Reference
[com.trolltech.qt.gui module]

The `QCheckBox` widget provides a checkbox with a text label. More...

Inherits `QAbstractButton`.

## Detailed Description

The `QCheckBox` widget provides a checkbox with a text label.

A `QCheckBox` is an option button that can be switched on (checked) or off (unchecked). Checkboxes are typically used to represent features in an application that can be enabled or disabled without affecting others, but different types of behavior can be implemented.

A `QButtonGroup` can be used to group check buttons visually.

Whenever a checkbox is checked or cleared it emits the signal `stateChanged`. Connect to this signal if you want to trigger an action each time the checkbox changes state. You can use `isChecked` to query whether or not a checkbox is checked.

In addition to the usual checked and unchecked states, `QCheckBox` optionally provides a third state to indicate "no change". This is useful whenever you need to give the user the option of neither checking nor unchecking a checkbox. If you need this third state, enable it with `setTristate`, and use `checkState` to query the current toggle state.

Just like `QPushButton`, a checkbox displays text, and optionally a small icon. The icon is set with `setIcon`. The text can be set in the constructor or with `setText`. A shortcut key can be specified by preceding the preferred character with an ampersand. For example:

        QCheckBox *checkbox = new QCheckBox("C&ase sensitive", this);

In this example the shortcut is Alt+A. See the QShortcut documentation for details (to display an actual ampersand, use '&&').

Important inherited functions: `text`, `setText`, `text`, `pixmap`, setPixmap(), accel(), setAccel(), isToggleButton(), `setDown`, `isDown`, isOn(), `checkState`, `autoRepeat`, isExclusiveToggle(), `group`, `setAutoRepeat`, `toggle`, `pressed`, `released`, `clicked`, `toggled`, `checkState`, and `stateChanged`.

| A checkbox shown in the Macintosh widget style.
| A checkbox shown in the Windows XP widget style.
| A checkbox shown in the Plastique widget style.

See also `QAbstractButton`, `QRadioButton`, and GUI Design Handbook: Check Box.