RadioButton class

Radio buttons, also called option buttons, let users select one option from a collection of two or more mutually exclusive, but related, options. Radio buttons are always used in groups, and each option is represented by one radio button in the group.

In the default state, no radio button in a RadioButtons group is selected. That is, all radio buttons are cleared. However, once a user has selected a radio button, the user can't deselect the button to restore the group to its initial cleared state.

The singular behavior of a RadioButtons group distinguishes it from check boxes, which support multi-selection and deselection, or clearing.

RadioButton

See also:

Inheritance

Constructors

RadioButton({Key? key, required bool checked, required ValueChanged<bool>? onChanged, RadioButtonThemeData? style, String? semanticLabel, FocusNode? focusNode, bool autofocus = false})
const

Properties

autofocus bool
True if this widget will be selected as the initial focus when no other node in its scope is currently focused.
final
checked bool
Whether the button is checked of not
final
focusNode FocusNode?
True if this widget will be selected as the initial focus when no other node in its scope is currently focused.
final
hashCode int
The hash code for this object.
no setterinherited
key Key?
Controls how one widget replaces another widget in the tree.
finalinherited
onChanged ValueChanged<bool>?
Called when the value of the button is changed. If this is null, the button is considered disabled
final
runtimeType Type
A representation of the runtime type of the object.
no setterinherited
semanticLabel String?
Semantic label for the input.
final
style RadioButtonThemeData?
The style of the button. If non-null, this is merged with ThemeData.radioButtonThemeData
final

Methods

build(BuildContext context) Widget
Describes the part of the user interface represented by this widget.
override
createElement() StatelessElement
Creates a StatelessElement to manage this widget's location in the tree.
inherited
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
override
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) String
A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object.
inherited
toStringShort() String
A short, textual description of this widget.
inherited

Operators

operator ==(Object other) bool
The equality operator.
inherited