BasePickerComponent class

An iOS-styled picker.

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

Can be used with showCupertinoModalPopup to display the picker modally at the bottom of the screen.

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.

See also:

• ListWheelScrollView, the generic widget backing this picker without the iOS design specific chrome.
• developer.apple.com/ios/human-interface-guidelines/controls/pickers/

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatefulWidget
• BasePickerComponent

Available extensions

• WidgetExtensions
• WidgetMarginX
• WidgetPaddingX
• WidgetSliverBoxX

Constructors

BasePickerComponent.new({Key? key, double diameterRatio = _kDefaultDiameterRatio, Color backgroundColor = _kDefaultBackground, Color? lineColor = _kHighlighterBorder, 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, bool looping = false})

Creates a picker from a concrete list of children.

BasePickerComponent.builder({Key? key, double diameterRatio = _kDefaultDiameterRatio, Color backgroundColor = _kDefaultBackground, Color? lineColor = _kHighlighterBorder, double offAxisFraction = 0.0, bool useMagnifier = false, double magnification = 1.0, FixedExtentScrollController? scrollController, double squeeze = _kSqueeze, required double itemExtent, required ValueChanged<int> onSelectedItemChanged, required IndexedWidgetBuilder itemBuilder, int? childCount})

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

debugRandomColor → Widget

Available on Widget, provided by the WidgetExtensions extension

no setter

diameterRatio → double

Relative ratio between this picker's height and the simulated cylinder's diameter.

final

hashCode → int

The hash code for this object.

no setter, inherited

itemExtent → double

The uniform height of all children.

final

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

lineColor → Color?

分割线颜色

final

magnification → double

final

marginZero → Widget

Available on Widget, provided by the WidgetMarginX extension

no setter

offAxisFraction → double

final

onSelectedItemChanged → ValueChanged<int>

An option callback when the currently centered item changes.

final

paddingZero → Widget

Available on Widget, provided by the WidgetPaddingX extension

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

scrollController → FixedExtentScrollController?

A FixedExtentScrollController to read and control the current item.

final

sliverBox → Widget

Available on Widget, provided by the WidgetSliverBoxX extension

no setter

squeeze → double

Defaults to 1.45 fo visually mimic iOS.

final

useMagnifier → bool

final

Methods

align(AlignmentGeometry alignment, {Key? key}) → Widget

Available on Widget, provided by the WidgetExtensions extension

对齐

alignBottom() → Widget

Available on Widget, provided by the WidgetExtensions extension

对齐 底部

alignCenter() → Widget

Available on Widget, provided by the WidgetExtensions extension

对齐 中间

alignLeft() → Widget

Available on Widget, provided by the WidgetExtensions extension

对齐 左边

alignRight() → Widget

Available on Widget, provided by the WidgetExtensions extension

对齐 右边

alignTop() → Widget

Available on Widget, provided by the WidgetExtensions extension

对齐 顶部

aspectRatio({Key? key, required double aspectRatio}) → Widget

Available on Widget, provided by the WidgetExtensions extension

backgroundColor(Color color, {Key? key}) → Widget

Available on Widget, provided by the WidgetExtensions extension

背景颜色

backgroundImage(DecorationImage image, {Key? key}) → Widget

Available on Widget, provided by the WidgetExtensions extension

背景图片

border({Key? key, double? all, double? left, double? right, double? top, double? bottom, Color color = const Color(0xFF000000), BorderStyle style = BorderStyle.solid}) → Widget

Available on Widget, provided by the WidgetExtensions extension

边框

borderRadius({Key? key, double? all, double? topLeft, double? topRight, double? bottomLeft, double? bottomRight}) → Widget

Available on Widget, provided by the WidgetExtensions extension

圆角

boxShadow({Key? key, Color color = const Color(0xFF000000), Offset offset = Offset.zero, double blurRadius = 0.0, double spreadRadius = 0.0}) → Widget

Available on Widget, provided by the WidgetExtensions extension

阴影

card({Key? key, double? radius, Color? color, Color? shadowColor, double? blurRadius}) → Widget

Available on Widget, provided by the WidgetExtensions extension

卡片

center({Key? key, double? widthFactor, double? heightFactor}) → Widget

Available on Widget, provided by the WidgetExtensions extension

clipOval({Key? key}) → Widget

Available on Widget, provided by the WidgetExtensions extension

裁剪 oval

clipRect({Key? key, CustomClipper<Rect>? clipper, Clip clipBehavior = Clip.hardEdge}) → Widget

Available on Widget, provided by the WidgetExtensions extension

裁剪 rect

clipRRect({Key? key, double? all, double? topLeft, double? topRight, double? bottomLeft, double? bottomRight, CustomClipper<RRect>? clipper, Clip clipBehavior = Clip.antiAlias}) → Widget

Available on Widget, provided by the WidgetExtensions extension

裁剪圆角

constrained({Key? key, double? width, double? height, double minWidth = 0.0, double maxWidth = double.infinity, double minHeight = 0.0, double maxHeight = double.infinity}) → Widget

Available on Widget, provided by the WidgetExtensions extension

约束

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.

inherited

debugFillProperties(DiagnosticPropertiesBuilder properties) → void

Add additional properties associated with the node.

inherited

decorated({Key? key, Color? color, DecorationImage? image, BoxBorder? border, BorderRadius? borderRadius, List<BoxShadow>? boxShadow, Gradient? gradient, BlendMode? backgroundBlendMode, BoxShape shape = BoxShape.rectangle, DecorationPosition position = DecorationPosition.background}) → Widget

Available on Widget, provided by the WidgetExtensions extension

盒子装饰器

elevation(double elevation, {Key? key, BorderRadiusGeometry borderRadius = BorderRadius.zero, Color shadowColor = const Color(0xFF000000)}) → Widget

Available on Widget, provided by the WidgetExtensions extension

elevation

expanded({Key? key, int flex = 1}) → Widget

Available on Widget, provided by the WidgetExtensions extension

expanded 撑满

fittedBox({Key? key, BoxFit fit = BoxFit.contain, AlignmentGeometry alignment = Alignment.centerLeft, Clip clipBehavior = Clip.none}) → Widget

Available on Widget, provided by the WidgetExtensions extension

flexible({Key? key, int flex = 1, FlexFit fit = FlexFit.loose}) → Widget

Available on Widget, provided by the WidgetExtensions extension

弹性布局 flexible

fractionallySizedBox({Key? key, AlignmentGeometry alignment = Alignment.center, double? widthFactor, double? heightFactor}) → Widget

Available on Widget, provided by the WidgetExtensions extension

gestures({Key? key, GestureOnTapChangeCallback? onTapChange, GestureTapDownCallback? onTapDown, GestureTapUpCallback? onTapUp, GestureTapCallback? onTap, GestureTapCancelCallback? onTapCancel, GestureTapDownCallback? onSecondaryTapDown, GestureTapUpCallback? onSecondaryTapUp, GestureTapCancelCallback? onSecondaryTapCancel, GestureTapCallback? onDoubleTap, GestureLongPressCallback? onLongPress, GestureLongPressStartCallback? onLongPressStart, GestureLongPressMoveUpdateCallback? onLongPressMoveUpdate, GestureLongPressUpCallback? onLongPressUp, GestureLongPressEndCallback? onLongPressEnd, GestureDragDownCallback? onVerticalDragDown, GestureDragStartCallback? onVerticalDragStart, GestureDragUpdateCallback? onVerticalDragUpdate, GestureDragEndCallback? onVerticalDragEnd, GestureDragCancelCallback? onVerticalDragCancel, GestureDragDownCallback? onHorizontalDragDown, GestureDragStartCallback? onHorizontalDragStart, GestureDragUpdateCallback? onHorizontalDragUpdate, GestureDragEndCallback? onHorizontalDragEnd, GestureDragCancelCallback? onHorizontalDragCancel, GestureDragDownCallback? onPanDown, GestureDragStartCallback? onPanStart, GestureDragUpdateCallback? onPanUpdate, GestureDragEndCallback? onPanEnd, GestureDragCancelCallback? onPanCancel, GestureScaleStartCallback? onScaleStart, GestureScaleUpdateCallback? onScaleUpdate, GestureScaleEndCallback? onScaleEnd, GestureForcePressStartCallback? onForcePressStart, GestureForcePressPeakCallback? onForcePressPeak, GestureForcePressUpdateCallback? onForcePressUpdate, GestureForcePressEndCallback? onForcePressEnd, HitTestBehavior? behavior, bool excludeFromSemantics = false, DragStartBehavior dragStartBehavior = DragStartBehavior.start}) → Widget

Available on Widget, provided by the WidgetExtensions extension

手势

height(double height, {Key? key}) → Widget

Available on Widget, provided by the WidgetExtensions extension

约束 高度

inkWell({Key? key, dynamic onTap()?, double? borderRadius}) → Widget

Available on Widget, provided by the WidgetExtensions extension

limitedBox({Key? key, double maxWidth = double.infinity, double maxHeight = double.infinity}) → Widget

Available on Widget, provided by the WidgetExtensions extension

限制盒子 最大宽高

marginAll(double margin) → Widget

Available on Widget, provided by the WidgetMarginX extension

marginOnly({double left = 0.0, double top = 0.0, double right = 0.0, double bottom = 0.0}) → Widget

Available on Widget, provided by the WidgetMarginX extension

marginSymmetric({double horizontal = 0.0, double vertical = 0.0}) → Widget

Available on Widget, provided by the WidgetMarginX extension

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

offstage({Key? key, bool offstage = true}) → Widget

Available on Widget, provided by the WidgetExtensions extension

偏移

onLongPress(GestureTapCallback? onLongPress, {Key? key, HitTestBehavior? behavior, bool excludeFromSemantics = false, DragStartBehavior dragStartBehavior = DragStartBehavior.start}) → Widget

Available on Widget, provided by the WidgetExtensions extension

长按手势

onTap(GestureTapCallback? onTap, {Key? key, HitTestBehavior? behavior, bool excludeFromSemantics = false, DragStartBehavior dragStartBehavior = DragStartBehavior.start}) → Widget

Available on Widget, provided by the WidgetExtensions extension

手势

opacity(double opacity, {Key? key, bool alwaysIncludeSemantics = false}) → Widget

Available on Widget, provided by the WidgetExtensions extension

透明度

overflow({Key? key, AlignmentGeometry alignment = Alignment.center, double? minWidth, double? maxWidth, double? minHeight, double? maxHeight}) → Widget

Available on Widget, provided by the WidgetExtensions extension

溢出

padding({Key? key, EdgeInsetsGeometry? value, double? all, double? horizontal, double? vertical, double? top, double? bottom, double? left, double? right}) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距

paddingAll(double padding) → Widget

Available on Widget, provided by the WidgetPaddingX extension

paddingBottom(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 下

paddingHorizontal(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 横向

paddingLeft(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 左

paddingOnly({double left = 0.0, double top = 0.0, double right = 0.0, double bottom = 0.0}) → Widget

Available on Widget, provided by the WidgetPaddingX extension

paddingRight(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 右

paddingSymmetric({double horizontal = 0.0, double vertical = 0.0}) → Widget

Available on Widget, provided by the WidgetPaddingX extension

paddingTop(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 上

paddingVertical(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 纵向

positioned({Key? key, double? left, double? top, double? right, double? bottom, double? width, double? height}) → Widget

Available on Widget, provided by the WidgetExtensions extension

stack布局 位置

ripple({Key? key, Color? focusColor, Color? hoverColor, Color? highlightColor, Color? splashColor, InteractiveInkFeatureFactory? splashFactory, double? radius, ShapeBorder? customBorder, bool enableFeedback = true, bool excludeFromSemantics = false, FocusNode? focusNode, bool canRequestFocus = true, bool autoFocus = false, bool enable = true}) → Widget

Available on Widget, provided by the WidgetExtensions extension

涟漪

safeArea({Key? key, bool top = true, bool bottom = true, bool left = true, bool right = true, EdgeInsets minimum = EdgeInsets.zero}) → Widget

Available on Widget, provided by the WidgetExtensions extension

安全区

scale({Key? key, double? all, double? x, double? y, Offset? origin, AlignmentGeometry alignment = Alignment.center, bool transformHitTests = true}) → Widget

Available on Widget, provided by the WidgetExtensions extension

比例缩放

scrollable({Key? key, Axis scrollDirection = Axis.vertical, bool reverse = false, bool? primary, ScrollPhysics? physics, ScrollController? controller, DragStartBehavior dragStartBehavior = DragStartBehavior.start, EdgeInsetsGeometry? padding}) → Widget

Available on Widget, provided by the WidgetExtensions extension

滚动视图

semanticsLabel(String label, {Key? key}) → Widget

Available on Widget, provided by the WidgetExtensions extension

语义调试 MaterialApp.showSemanticsDebugger: true,

sliverPadding({Key? key, EdgeInsetsGeometry? value, double? all, double? horizontal, double? vertical, double? top, double? bottom, double? left, double? right}) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距

sliverPaddingBottom(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 下

sliverPaddingHorizontal(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 横向

sliverPaddingLeft(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 左

sliverPaddingRight(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 右

sliverPaddingTop(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 上

sliverPaddingVertical(double val) → Widget

Available on Widget, provided by the WidgetExtensions extension

内间距 纵向

sliverToBoxAdapter({Key? key}) → Widget

Available on Widget, provided by the WidgetExtensions extension

SliverToBoxAdapter

tight({double? width, double? height, Key? key}) → Widget

Available on Widget, provided by the WidgetExtensions extension

约束 宽高

tightSize(double size, {Key? key}) → Widget

Available on Widget, provided by the WidgetExtensions extension

约束 宽高 size

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, int wrapWidth = 65}) → 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

transform({Key? key, required Matrix4 transform, Offset? origin, AlignmentGeometry? alignment, bool transformHitTests = true}) → Widget

Available on Widget, provided by the WidgetExtensions extension

transforms Matrix4

translate({Key? key, required Offset offset, bool transformHitTests = true}) → Widget

Available on Widget, provided by the WidgetExtensions extension

translate 变化位置

unconstrained({Key? key, TextDirection? textDirection, AlignmentGeometry alignment = Alignment.center, Axis? constrainedAxis, Clip clipBehavior = Clip.none}) → Widget

Available on Widget, provided by the WidgetExtensions extension

width(double width, {Key? key}) → Widget

Available on Widget, provided by the WidgetExtensions extension

约束 宽度

Operators

operator ==(Object other) → bool

The equality operator.

inherited