CircularProgressIndicator class Null safety
A Material Design circular progress indicator, which spins to indicate that the application is busy.
A widget that shows progress along a circle. There are two kinds of circular 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 arc is displayed with valueColor, an animated value. To
specify a constant color use: AlwaysStoppedAnimation<Color>(color).
This example shows a CircularProgressIndicator with a changing value.
        
        To create a local project with this code sample, run:
flutter create --sample=material.CircularProgressIndicator.1 mysample
    flutter create --sample=material.CircularProgressIndicator.1 mysample
See also:
- LinearProgressIndicator, which displays progress along a line.
- RefreshIndicator, which automatically displays a CircularProgressIndicator when the underlying vertical scrollable is overscrolled.
- material.io/design/components/progress-indicators.html#circular-progress-indicators
- Inheritance
- 
    - Object
- DiagnosticableTree
- Widget
- StatefulWidget
- ProgressIndicator
- CircularProgressIndicator
 
- Implementers
Constructors
- 
          CircularProgressIndicator({Key? key, double? value, Color? backgroundColor, Color? color, Animation<Color?> ? valueColor, double strokeWidth = 4.0, String? semanticsLabel, String? semanticsValue})
- 
          Creates a circular progress indicator.
            const
- 
          CircularProgressIndicator.adaptive({Key? key, double? value, Color? backgroundColor, Animation<Color?> ? valueColor, double strokeWidth = 4.0, String? semanticsLabel, String? semanticsValue})
- 
          Creates an adaptive progress indicator that is a
CupertinoActivityIndicator in iOS and CircularProgressIndicator in
material theme/non-iOS.
            const
Properties
- backgroundColor → Color?
- 
  Color of the circular track being filled by the circular indicator.
  read-onlyoverride
- color → Color?
- 
  The progress indicator's color.
  finalinherited
- hashCode → int
- The hash code for this object.
- key → Key?
- 
  Controls how one widget replaces another widget in the tree.
  finalinherited
- runtimeType → Type
- 
  A representation of the runtime type of the object.
  read-onlyinherited
- semanticsLabel → String?
- 
  The SemanticsProperties.label for this progress indicator.
  finalinherited
- semanticsValue → String?
- 
  The SemanticsProperties.value for this progress indicator.
  finalinherited
- strokeWidth → double
- 
  The width of the line used to draw the circle.
  final
- 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< CircularProgressIndicator> 
- 
  Creates the mutable state for this widget at a given location in the tree.
  override
- 
  debugDescribeChildren() → List< DiagnosticsNode> 
- 
  Returns a list of DiagnosticsNodeobjects 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
Operators
- 
  operator ==(Object other) → bool 
- 
  The equality operator.
  nonVirtual">@nonVirtualinherited