AnimatedContainer class Null safety

Animated version of Container that gradually changes its values over a period of time.

The AnimatedContainer will automatically animate between the old and new values of properties when they change using the provided curve and duration. Properties that are null are not animated. Its child and descendants are not animated.

This class is useful for generating simple implicit transitions between different parameters to Container with its internal AnimationController. For more complex animations, you'll likely want to use a subclass of AnimatedWidget such as the DecoratedBoxTransition or use your own AnimationController.

The following example (depicted above) transitions an AnimatedContainer between two states. It adjusts the height, width, color, and alignment properties when tapped.
To create a local project with this code sample, run:
flutter create --sample=widgets.AnimatedContainer.1 mysample

See also:



AnimatedContainer({Key? key, AlignmentGeometry? alignment, EdgeInsetsGeometry? padding, Color? color, Decoration? decoration, Decoration? foregroundDecoration, double? width, double? height, BoxConstraints? constraints, EdgeInsetsGeometry? margin, Matrix4? transform, AlignmentGeometry? transformAlignment, Widget? child, Clip clipBehavior = Clip.none, Curve curve = Curves.linear, required Duration duration, VoidCallback? onEnd})
Creates a container that animates its parameters implicitly.


alignment AlignmentGeometry?
Align the child within the container.
child Widget?
The child contained by the container.
clipBehavior Clip
The clip behavior when AnimatedContainer.decoration is not null.
constraints BoxConstraints?
Additional constraints to apply to the child.
curve Curve
The curve to apply when animating the parameters of this container.
final, inherited
decoration Decoration?
The decoration to paint behind the child.
duration Duration
The duration over which to animate the parameters of this container.
final, inherited
foregroundDecoration Decoration?
The decoration to paint in front of the child.
hashCode int
The hash code for this object.
@nonVirtual, read-only, inherited
key Key?
Controls how one widget replaces another widget in the tree.
final, inherited
margin EdgeInsetsGeometry?
Empty space to surround the decoration and child.
onEnd VoidCallback?
Called every time an animation completes.
final, inherited
padding EdgeInsetsGeometry?
Empty space to inscribe inside the decoration. The child, if any, is placed inside this padding.
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited
transform Matrix4?
The transformation matrix to apply before painting the container.
transformAlignment AlignmentGeometry?
The alignment of the origin, relative to the size of the container, if transform is specified.


createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
createState() AnimatedWidgetBaseState<AnimatedContainer>
Creates the mutable state for this widget at a given location in the tree.
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
@protected, inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
toString({DiagnosticLevel minLevel =}) String
A string representation of this object.
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants.
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object.
toStringShort() String
A short, textual description of this widget.


operator ==(Object other) bool
The equality operator.
@nonVirtual, inherited