ExpandedModifier class

A widget that expands a child of a Row, Column, or Flex so that the child fills the available space.

Using an Expanded widget makes a child of a Row, Column, or Flex expand to fill the available space along the main axis (e.g., horizontally for a Row or vertically for a Column). If multiple children are expanded, the available space is divided among them according to the flex factor.

An Expanded widget must be a descendant of a Row, Column, or Flex, and the path from the Expanded widget to its enclosing Row, Column, or Flex must contain only StatelessWidgets or StatefulWidgets (not other kinds of widgets, like RenderObjectWidgets).

{@tool dartpad} This example shows how to use an Expanded widget in a Column so that its middle child, a Container here, expands to fill the space.

** See code in examples/api/lib/widgets/basic/expanded.0.dart ** {@end-tool}

{@tool dartpad} This example shows how to use an Expanded widget in a Row with multiple children expanded, utilizing the flex factor to prioritize available space.

** See code in examples/api/lib/widgets/basic/expanded.1.dart ** {@end-tool}

See also:

• Flexible, which does not force the child to fill the available space.
• Spacer, a widget that takes up space proportional to its flex value.
• The catalog of layout widgets.

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• SingleChildStatelessModifier
• FlexibleModifier
• ExpandedModifier

Available extensions

• ModifierTransformer

Constructors

ExpandedModifier({Key? key, Widget? child, int? flex})

Creates a widget that expands a child of a Row, Column, or Flex so that the child fills the available space along the flex widget's main axis.

const

Properties

fit → FlexFit

How a flexible child is inscribed into the available space.

final, inherited

flex → int

The flex factor to use for this child.

final, inherited

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

modifierKey → Key?

The actual key of the widget, which Modifier wrapped

final, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

build(BuildContext context) → Widget

Describes the part of the user interface represented by this widget.

inherited

buildWithChild(BuildContext context, Widget? child) → Widget

A build method that receives an extra child parameter.

inherited

createElement() → SingleChildStatelessElement

Create a SingleChildStatelessElement

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.

inherited

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