SnackBar class Null safety

A lightweight message with an optional action which briefly displays at the bottom of the screen.

To display a snack bar, call ScaffoldMessenger.of(context).showSnackBar(), passing an instance of SnackBar that describes the message.

To control how long the SnackBar remains visible, specify a duration.

A SnackBar with an action will not time out when TalkBack or VoiceOver are enabled. This is controlled by AccessibilityFeatures.accessibleNavigation.

During page transitions, the SnackBar will smoothly animate to its location on the other page. For example if the SnackBar.behavior is set to SnackBarBehavior.floating and the next page has a floating action button, while the current one does not, the SnackBar will smoothly animate above the floating action button. It also works in the case of a back gesture transition.

Here is an example of a SnackBar with an action button implemented using SnackBarAction.

To create a local project with this code sample, run:
flutter create --sample=material.SnackBar.1 mysample

Here is an example of a customized SnackBar. It utilizes behavior, shape, padding, width, and duration to customize the location, appearance, and the duration for which the SnackBar is visible.

To create a local project with this code sample, run:
flutter create --sample=material.SnackBar.2 mysample

Constructors

SnackBar({Key? key, required Widget content, Color? backgroundColor, double? elevation, EdgeInsetsGeometry? margin, EdgeInsetsGeometry? padding, double? width, ShapeBorder? shape, SnackBarBehavior? behavior, SnackBarAction? action, Duration duration = _snackBarDisplayDuration, Animation<double>? animation, VoidCallback? onVisible, DismissDirection dismissDirection = DismissDirection.down, Clip clipBehavior = Clip.hardEdge}): Creates a snack bar.
const

Properties

action → SnackBarAction?: (optional) An action that the user can take based on the snack bar.
final
animation → Animation<double>?: The animation driving the entrance and exit of the snack bar.
final
backgroundColor → Color?: The snack bar's background color. If not specified it will use SnackBarThemeData.backgroundColor of ThemeData.snackBarTheme. If that is not specified it will default to a dark variation of ColorScheme.surface for light themes, or ColorScheme.onSurface for dark themes.
final
behavior → SnackBarBehavior?: This defines the behavior and location of the snack bar.
final
clipBehavior → Clip: The content will be clipped (or not) according to this option.
final
content → Widget: The primary content of the snack bar.
final
dismissDirection → DismissDirection: The direction in which the SnackBar can be dismissed.
final
duration → Duration: The amount of time the snack bar should be displayed.
final
elevation → double?: The z-coordinate at which to place the snack bar. This controls the size of the shadow below the snack bar.
final
hashCode → int: The hash code for this object.
nonVirtual">@nonVirtualread-onlyinherited
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
margin → EdgeInsetsGeometry?: Empty space to surround the snack bar.
final
onVisible → VoidCallback?: Called the first time that the snackbar is visible within a Scaffold.
final
padding → EdgeInsetsGeometry?: The amount of padding to apply to the snack bar's content and optional action.
final
runtimeType → Type: A representation of the runtime type of the object.
read-onlyinherited
shape → ShapeBorder?: The shape of the snack bar's Material.
final
width → double?: The width of the snack bar.
final

Methods

createElement() → StatefulElement: Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<SnackBar>: Creates the mutable state for this widget at a given location in the tree.
override
debugDescribeChildren() → List<DiagnosticsNode>: Returns a list of DiagnosticsNode objects describing this node's children.
protected">@protectedinherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void: Add additional properties associated with the node.
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 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
withAnimation(Animation<double> newAnimation, {Key? fallbackKey}) → SnackBar: Creates a copy of this snack bar but with the animation replaced with the given animation.

Operators

operator ==(Object other) → bool: The equality operator.
nonVirtual">@nonVirtualinherited

Static Methods

createAnimationController({required TickerProvider vsync}) → AnimationController: Creates an animation controller useful for driving a snack bar's entrance and exit animation.

Flutter
material
SnackBar class