Qt 5.6 | Qt Widgets | C++ Classes | QRadioButton

Qt 5.6.2 Reference Documentation

# QRadioButton Class

The QRadioButton widget provides a radio button with a text label. More...

Header: | #include <QRadioButton>
qmake: | QT += widgets
Inherits: | QAbstractButton

- List of all members, including inherited members

## Public Functions

| QRadioButton(QWidget *parent = Q_NULLPTR)
| QRadioButton(const QString &text, QWidget *parent = Q_NULLPTR)
| ~QRadioButton()

## Reimplemented Public Functions

virtual QSize | minimumSizeHint() const
virtual QSize | sizeHint() const

- 21 public functions inherited from QAbstractButton
- 211 public functions inherited from QWidget

## Protected Functions

bool | event(QEvent *e)
void | initStyleOption(QStyleOptionButton *option) const

## Reimplemented Protected Functions

virtual bool | hitButton(const QPoint &pos) const
virtual void | mouseMoveEvent(QMouseEvent *e)
virtual void | paintEvent(QPaintEvent *)

- 14 protected functions inherited from QAbstractButton
- 35 protected functions inherited from QWidget

### Additional Inherited Members

- 11 properties inherited from QAbstractButton
- 58 properties inherited from QWidget
- 5 public slots inherited from QAbstractButton
- 19 public slots inherited from QWidget
- 4 signals inherited from QAbstractButton
- 3 signals inherited from QWidget
- 5 static public members inherited from QWidget
- 1 protected slot inherited from QWidget

## Detailed Description

The QRadioButton widget provides a radio button with a text label.

A QRadioButton is an option button that can be switched on (checked) or off (unchecked). Radio buttons typically present the user with a "one of many" choice. In a group of radio buttons, only one radio button at a time can be checked; if the user selects another button, the previously selected button is switched off.

Radio buttons are autoExclusive by default. If auto-exclusive is enabled, radio buttons that belong to the same parent widget behave as if they were part of the same exclusive button group. If you need multiple exclusive button groups for radio buttons that belong to the same parent widget, put them into a QButtonGroup.

Whenever a button is switched on or off, it emits the toggled() signal. Connect to this signal if you want to trigger an action each time the button changes state. Use isChecked() to see if a particular button is selected.

Just like QPushButton, a radio button 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 in the text. For example:

      QRadioButton *button = new QRadioButton("Search from the &cursor", this);

In this example the shortcut is Alt+c. See the QShortcut documentation for details. To display an actual ampersand, use '&&'.

Important inherited members: text(), setText(), text(), setDown(), isDown(), autoRepeat(), group(), setAutoRepeat(), toggle(), pressed(), released(), clicked(), and toggled().

| A radio button shown in the Fusion widget style.
| A radio button shown in the Windows Vista widget style.
| A radio button shown in the Macintosh widget style.

See also QPushButton, QToolButton, QCheckBox, GUI Design Handbook: Radio Button, and Group Box Example.

## Member Function Documentation

### QRadioButton::QRadioButton(QWidget *parent = Q_NULLPTR)

Constructs a radio button with the given parent, but with no text or pixmap.

The parent argument is passed on to the QAbstractButton constructor.

### QRadioButton::QRadioButton(const QString &text, QWidget *parent = Q_NULLPTR)

Constructs a radio button with the given parent and text string.

The parent argument is passed on to the QAbstractButton constructor.

### QRadioButton::~QRadioButton()

Destructor.

### `[protected]` bool QRadioButton::event(QEvent *e)

### `[virtual protected]` bool QRadioButton::hitButton(const QPoint &pos) const

Reimplemented from QAbstractButton::hitButton().

### `[protected]` void QRadioButton::initStyleOption(QStyleOptionButton *option) const

Initialize option with the values from this QRadioButton. This method is useful for subclasses when they need a QStyleOptionButton, but don't want to fill in all the information themselves.

See also QStyleOption::initFrom().

### `[virtual]` QSize QRadioButton::minimumSizeHint() const

Reimplemented from QWidget::minimumSizeHint().

### `[virtual protected]` void QRadioButton::mouseMoveEvent(QMouseEvent *e)

Reimplemented from QWidget::mouseMoveEvent().

### `[virtual protected]` void QRadioButton::paintEvent(QPaintEvent *)

Reimplemented from QWidget::paintEvent().

### `[virtual]` QSize QRadioButton::sizeHint() const

Reimplemented from QWidget::sizeHint().