LinearProgressIndicator class

A Material Design linear progress indicator, also known as a progress bar.

A widget that shows progress along a line. There are two kinds of linear progress indicators:

  • Determinate. Determinate progress indicators have a specific value at each point in time, and the value should increase monotonically from 0.0 to 1.0, at which time the indicator is complete. To create a determinate progress indicator, use a non-null value between 0.0 and 1.0.
  • Indeterminate. Indeterminate progress indicators do not have a specific value at each point in time and instead indicate that progress is being made without indicating how much progress remains. To create an indeterminate progress indicator, use a null value.

The indicator line is displayed with valueColor, an animated value. To specify a constant color value use: AlwaysStoppedAnimation<Color>(color).

The minimum height of the indicator can be specified using minHeight. The indicator can be made taller by wrapping the widget with a SizedBox.

This example shows a LinearProgressIndicator with a changing value.
link

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

This sample shows the creation of a LinearProgressIndicator with a changing value. When toggling the switch, LinearProgressIndicator uses a determinate value. As described in: https://m3.material-io.cn/components/progress-indicators/overview
link

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

See also:

Inheritance

Constructors

LinearProgressIndicator({Key? key, double? value, Color? backgroundColor, Color? color, Animation<Color?>? valueColor, double? minHeight, String? semanticsLabel, String? semanticsValue, BorderRadiusGeometry borderRadius = BorderRadius.zero})
Creates a linear progress indicator.
const

Properties

backgroundColor Color?
Color of the track being filled by the linear indicator.
no setteroverride
borderRadius BorderRadiusGeometry
The border radius of both the indicator and the track.
final
color Color?
The progress indicator's color.
finalinherited
hashCode int
The hash code for this object.
no setterinherited
key Key?
Controls how one widget replaces another widget in the tree.
finalinherited
minHeight double?
The minimum height of the line used to draw the linear indicator.
final
runtimeType Type
A representation of the runtime type of the object.
no setterinherited
semanticsLabel String?
The SemanticsProperties.label for this progress indicator.
finalinherited
semanticsValue String?
The SemanticsProperties.value for this progress indicator.
finalinherited
value double?
If non-null, the value of this progress indicator.
finalinherited
valueColor Animation<Color?>?
The progress indicator's color as an animated value.
finalinherited

Methods

createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() State<LinearProgressIndicator>
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.
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