SizedBox class
A box with a specified size.
If given a child, this widget forces its child to have a specific width and/or height (assuming values are permitted by this widget's parent). If either the width or height is null, this widget will size itself to match the child's size in that dimension.
If not given a child, this widget will size itself to the given width and height, treating nulls as zero.
The new SizedBox.expand constructor can be used to make a SizedBox that sizes itself to fit the parent. It is equivalent to setting width and height to double.infinity.
See also:
- ConstrainedBox, a more generic version of this class that takes arbitrary BoxConstraints instead of an explicit width and height.
- UnconstrainedBox, a container that tries to let its child draw without constraints.
- FractionallySizedBox, a widget that sizes its child to a fraction of the total available space.
- AspectRatio, a widget that attempts to fit within the parent's constraints while also sizing its child to match a given aspect ratio.
- FittedBox, which sizes and positions its child widget to fit the parent according to a given BoxFit discipline.
- The catalog of layout widgets.
- Inheritance
Constructors
- SizedBox({Key key, double width, double height, Widget child })
-
Creates a fixed size box. The
width
andheight
parameters can be null to indicate that the size of the box should not be constrained in the corresponding dimension.const - SizedBox.expand({Key key, Widget child })
-
Creates a box that will become as large as its parent allows.
const
- SizedBox.fromSize({Key key, Widget child, Size size })
- Creates a box with the specified size.
- SizedBox.shrink({Key key, Widget child })
-
Creates a box that will become as small as its parent allows.
const
Properties
- height → double
-
If non-null, requires the child to have exactly this height.
final
- width → double
-
If non-null, requires the child to have exactly this width.
final
- child → Widget
-
The widget below this widget in the tree. [...]
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
Methods
-
createRenderObject(
BuildContext context) → RenderConstrainedBox -
Creates an instance of the RenderObject class that this
RenderObjectWidget represents, using the configuration described by this
RenderObjectWidget. [...]
override
-
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void -
Add additional properties associated with the node. [...]
override
-
toStringShort(
) → String -
A short, textual description of this widget.
override
-
updateRenderObject(
BuildContext context, covariant RenderConstrainedBox renderObject) → void -
Copies the configuration described by this RenderObjectWidget to the
given RenderObject, which will be of the same type as returned by this
object's createRenderObject. [...]
override
-
createElement(
) → SingleChildRenderObjectElement -
RenderObjectWidgets always inflate to a RenderObjectElement subclass.
inherited
-
debugDescribeChildren(
) → List< DiagnosticsNode> -
Returns a list of DiagnosticsNode objects describing this node's
children. [...]
@protected, inherited
-
didUnmountRenderObject(
covariant RenderObject renderObject) → void -
A render object previously associated with this widget has been removed
from the tree. The given RenderObject will be of the same type as
returned by this object's createRenderObject.
@protected, inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent 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 toStringDeep. [...]
inherited
-
toString(
{DiagnosticLevel minLevel: DiagnosticLevel.debug }) → String -
Returns 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
Operators
-
operator ==(
dynamic other) → bool -
The equality operator. [...]
inherited