CupertinoPicker class Null safety

An iOS-styled picker.

Displays its children widgets on a wheel for selection and calls back when the currently selected item changes.

By default, the first child in children will be the initially selected child. The index of a different child can be specified in scrollController, to make that child the initially selected child.

Can be used with showCupertinoModalPopup to display the picker modally at the bottom of the screen. When calling showCupertinoModalPopup, be sure to set semanticsDismissible to true to enable dismissing the modal via semantics.

Sizes itself to its parent. All children are sized to the same size based on itemExtent.

By default, descendent texts are shown with CupertinoTextThemeData.pickerTextStyle.

link
This example shows a CupertinoPicker that displays a list of fruits on a wheel for selection.
To create a local project with this code sample, run:
flutter create --sample=cupertino.CupertinoPicker.1 mysample

See also:

Inheritance

Constructors

CupertinoPicker({Key? key, double diameterRatio = _kDefaultDiameterRatio, Color? backgroundColor, double offAxisFraction = 0.0, bool useMagnifier = false, double magnification = 1.0, FixedExtentScrollController? scrollController, double squeeze = _kSqueeze, required double itemExtent, required ValueChanged<int>? onSelectedItemChanged, required List<Widget> children, Widget? selectionOverlay = const CupertinoPickerDefaultSelectionOverlay(), bool looping = false})
Creates a picker from a concrete list of children.
CupertinoPicker.builder({Key? key, double diameterRatio = _kDefaultDiameterRatio, Color? backgroundColor, double offAxisFraction = 0.0, bool useMagnifier = false, double magnification = 1.0, FixedExtentScrollController? scrollController, double squeeze = _kSqueeze, required double itemExtent, required ValueChanged<int>? onSelectedItemChanged, required NullableIndexedWidgetBuilder itemBuilder, int? childCount, Widget? selectionOverlay = const CupertinoPickerDefaultSelectionOverlay()})
Creates a picker from an IndexedWidgetBuilder callback where the builder is dynamically invoked during layout.

Properties

backgroundColor → Color?
Background color behind the children.
final
childDelegate → ListWheelChildDelegate
A delegate that lazily instantiates children.
final
diameterRatio → double
Relative ratio between this picker's height and the simulated cylinder's diameter.
final
hashCode → int
The hash code for this object.
nonVirtual">@nonVirtualread-onlyinherited
itemExtent → double
The uniform height of all children.
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
magnification → double
The zoomed-in rate of the magnifier, if it is used.
final
offAxisFraction → double
How much the wheel is horizontally off-center, as a fraction of its width. This property creates the visual effect of looking at a vertical wheel from its side where its vanishing points at the edge curves to one side instead of looking at the wheel head-on.
final
onSelectedItemChanged → ValueChanged<int>?
An option callback when the currently centered item changes.
final
runtimeType → Type
A representation of the runtime type of the object.
read-onlyinherited
scrollController → FixedExtentScrollController?
A FixedExtentScrollController to read and control the current item, and to set the initial item.
final
selectionOverlay → Widget?
A widget overlaid on the picker to highlight the currently selected entry.
final
squeeze → double
The angular compactness of the children on the wheel.
final
useMagnifier → bool
Whether to use the magnifier for the center item of the wheel.
final

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
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.
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