Checkbox class

A check box is used to select or deselect action items.

It can be used for a single item or for a list of multiple items that a user can choose from. The control has three selection states: unselected (false), selected (true), and indeterminate (null). Use the indeterminate state when a collection of sub-choices have both unselected and selected states.

{@tool snippet} This example shows a basic checkbox:

bool isChecked = false;

Checkbox(
  checked: isChecked,
  onChanged: (value) => setState(() => isChecked = value ?? false),
)

{@end-tool}

{@tool snippet} This example shows a checkbox with a label:

Checkbox(
  checked: isAccepted,
  content: Text('I accept the terms and conditions'),
  onChanged: (value) => setState(() => isAccepted = value ?? false),
)

{@end-tool}

{@tool snippet} This example shows a three-state checkbox used to represent a group:

// null = indeterminate (some children checked)
// true = all children checked
// false = no children checked
bool? parentChecked;

Checkbox(
  checked: parentChecked,
  content: Text('Select all'),
  onChanged: (value) {
    setState(() {
      // When clicked, toggle between checked and unchecked
      parentChecked = value == true ? true : false;
    });
  },
)

{@end-tool}

Checkbox vs other controls

Use a checkbox when:

• Users can select zero, one, or multiple items from a list
• Items in the list are independent (selecting one doesn't affect others)
• You want to show the current selection state at a glance

Consider using:

• RadioButton when users must select exactly one option
• ToggleSwitch for binary on/off settings that take effect immediately
• ToggleButton for a button that maintains a toggled state

See also:

• ToggleSwitch, which represents a physical switch that allows users to turn things on or off immediately
• RadioButton, lets users select one option from a collection of two or more mutually exclusive, visible options
• ToggleButton, a button that can be toggled on or off
• learn.microsoft.com/en-us/windows/apps/design/controls/checkbox

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• Checkbox

Constructors

Checkbox({required bool? checked, required ValueChanged<bool?>? onChanged, Key? key, CheckboxThemeData? style, Widget? content, String? semanticLabel, FocusNode? focusNode, bool autofocus = false})

Creates a checkbox.

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 checkbox is checked or not.

final

content → Widget?

The content of the radio button.

final

focusNode → FocusNode?

An optional focus node to use as the focus node for this widget.

final

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

onChanged → ValueChanged<bool?>?

Called when the value of the Checkbox should change.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

semanticLabel → String?

Semantic label for the input.

final

style → CheckboxThemeData?

The style applied to the checkbox. If non-null, it's mescled with FluentThemeData.checkboxThemeData

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, int wrapWidth = 65}) → 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