A widget that expands a child of a Row, Column, or Flex.

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

See also:

  • Flexible, which does not force the child to fill the available space.


Expanded({Key key, int flex: 1, @required Widget child })

Creates a widget that expands a child of a Row, Column, or Flex expand to fill the available space in the main axis.



child Widget

The widget below this widget in the tree.

final, inherited
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.

read-only, inherited
key Key

Controls how one widget replaces another widget in the tree.

final, inherited
runtimeType Type

A representation of the runtime type of the object.

read-only, inherited


operator ==(other) bool

The equality operator.



applyParentData(RenderObject renderObject) → void

Write the data from this widget into the given render object's parent data.

createElement() ParentDataElement<Flex>

Inflates this configuration to a concrete instance.

debugDescribeInvalidAncestorChain({String description, String ownershipChain, bool foundValidAncestor, Iterable<Widget> badAncestors }) String

Subclasses should override this to describe the requirements for using the ParentDataWidget subclass. It is called when debugIsValidAncestor() returned false for an ancestor, or when there are extraneous ParentDataWidgets in the ancestor chain.

debugFillDescription(List<String> description) → void

Add additional information to the given description for use by toString.

debugIsValidAncestor(RenderObjectWidget ancestor) bool

Subclasses should override this method to return true if the given ancestor is a RenderObjectWidget that wraps a RenderObject that can handle the kind of ParentData widget that the ParentDataWidget subclass handles.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a non-existent method or property is accessed.

toString() String

Returns a string representation of this object.

toStringShort() String

A short, textual description of this widget.