StatefulBuilderModifier class

A platonic widget that both has state and calls a closure to obtain its child widget.

The StateSetter function passed to the builder is used to invoke a rebuild instead of a typical State's State.setState.

Since the builder is re-invoked when the StateSetter is called, any variables that represents state should be kept outside the builder function.

{@tool snippet}

This example shows using an inline StatefulBuilder that rebuilds and that also has state.

await showDialog<void>(
  context: context,
  builder: (BuildContext context) {
    int? selectedRadio = 0;
    return AlertDialog(
      content: StatefulBuilder(
        builder: (BuildContext context, StateSetter setState) {
          return Column(
            mainAxisSize: MainAxisSize.min,
            children: List<Widget>.generate(4, (int index) {
              return Radio<int>(
                value: index,
                groupValue: selectedRadio,
                onChanged: (int? value) {
                  setState(() => selectedRadio = value);
                },
              );
            }),
          );
        },
      ),
    );
  },
);

{@end-tool}

See also:

  • Builder, the platonic stateless widget.
Inheritance
Available extensions

Constructors

StatefulBuilderModifier({Key? key, Key? modifierKey, required SingleChildStatefulWidgetBuilder builder})
Creates a widget that both has state and delegates its build to a callback.
const

Properties

builder → SingleChildStatefulWidgetBuilder
Called to obtain the child widget.
final
hashCode → int
The hash code for this object.
no setterinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
modifierKey → Key?
The actual key of the widget, which Modifier wrapped
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

createElement() → SingleChildStatefulElement
Create element SingleChildStatefulElement
inherited
createState() → State<StatefulWidget>
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