Nil class

一个简单的小部件，当您想不显示任何内容时，可以添加到小部件树中，对性能的影响最小。

Inheritance

• Object
• DiagnosticableTree
• Widget
• Nil

Available extensions

• WidgetChainExt

Constructors

Nil.new({Key? key})

const

Properties

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

absorbPointer({Key? key, bool absorbing = true}) → AbsorbPointer

Available on Widget, provided by the WidgetChainExt extension

用AbsorbPointer包裹当前组件

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

Available on Widget, provided by the WidgetChainExt extension

用Align包裹当前组件

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

Available on Widget, provided by the WidgetChainExt extension

用Center包裹当前组件

click(GestureTapCallback? onTap) → Widget

Available on Widget, provided by the WidgetChainExt extension

有点击效果的点击事件

clipOval({Key? key, Clip clipBehavior = Clip.antiAlias, CustomClipper<Rect>? clipper}) → ClipOval

Available on Widget, provided by the WidgetChainExt extension

clipPath({Key? key, Clip clipBehavior = Clip.antiAlias, CustomClipper<Path>? clipper}) → ClipPath

Available on Widget, provided by the WidgetChainExt extension

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

Available on Widget, provided by the WidgetChainExt extension

clipRRect({Key? key, BorderRadiusGeometry borderRadius = BorderRadius.zero, Clip clipBehavior = Clip.antiAlias, CustomClipper<RRect>? clipper}) → ClipRRect

Available on Widget, provided by the WidgetChainExt extension

coloredBox(Color color, {Key? key}) → ColoredBox

Available on Widget, provided by the WidgetChainExt extension

用ColoredBox包裹当前组件

constrainedBox(BoxConstraints constraints, {Key? key}) → ConstrainedBox

Available on Widget, provided by the WidgetChainExt extension

用ConstrainedBox包裹当前组件

container({Key? key, AlignmentGeometry? alignment, EdgeInsetsGeometry? padding, Color? color, Decoration? decoration, Decoration? foregroundDecoration, double? width, double? height, BoxConstraints? constraints, EdgeInsetsGeometry? margin, Matrix4? transform, AlignmentGeometry? transformAlignment, Clip clipBehavior = Clip.none}) → Container

Available on Widget, provided by the WidgetChainExt extension

用Container包裹当前组件

createElement() → Element

Inflates this configuration to a concrete instance.

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

decoratedBox(Decoration decoration, {Key? key, DecorationPosition position = DecorationPosition.background}) → DecoratedBox

Available on Widget, provided by the WidgetChainExt extension

用DecoratedBox包裹当前组件

enfold(Widget builder(Widget child)) → Widget

Available on Widget, provided by the WidgetChainExt extension

包裹当前组件

expanded(int flex, {Key? key}) → Expanded

Available on Widget, provided by the WidgetChainExt extension

用Expanded包裹当前组件

gestureDetector({Key? key, GestureTapDownCallback? onTapDown, GestureTapUpCallback? onTapUp, GestureTapCallback? onTap, GestureTapCancelCallback? onTapCancel, GestureTapCallback? onSecondaryTap, GestureTapDownCallback? onSecondaryTapDown, GestureTapUpCallback? onSecondaryTapUp, GestureTapCancelCallback? onSecondaryTapCancel, GestureTapDownCallback? onTertiaryTapDown, GestureTapUpCallback? onTertiaryTapUp, GestureTapCancelCallback? onTertiaryTapCancel, GestureTapDownCallback? onDoubleTapDown, GestureTapCallback? onDoubleTap, GestureTapCancelCallback? onDoubleTapCancel, GestureLongPressDownCallback? onLongPressDown, GestureLongPressCancelCallback? onLongPressCancel, GestureLongPressCallback? onLongPress, GestureLongPressStartCallback? onLongPressStart, GestureLongPressMoveUpdateCallback? onLongPressMoveUpdate, GestureLongPressUpCallback? onLongPressUp, GestureLongPressEndCallback? onLongPressEnd, GestureLongPressDownCallback? onSecondaryLongPressDown, GestureLongPressCancelCallback? onSecondaryLongPressCancel, GestureLongPressCallback? onSecondaryLongPress, GestureLongPressStartCallback? onSecondaryLongPressStart, GestureLongPressMoveUpdateCallback? onSecondaryLongPressMoveUpdate, GestureLongPressUpCallback? onSecondaryLongPressUp, GestureLongPressEndCallback? onSecondaryLongPressEnd, GestureLongPressDownCallback? onTertiaryLongPressDown, GestureLongPressCancelCallback? onTertiaryLongPressCancel, GestureLongPressCallback? onTertiaryLongPress, GestureLongPressStartCallback? onTertiaryLongPressStart, GestureLongPressMoveUpdateCallback? onTertiaryLongPressMoveUpdate, GestureLongPressUpCallback? onTertiaryLongPressUp, GestureLongPressEndCallback? onTertiaryLongPressEnd, GestureDragDownCallback? onVerticalDragDown, GestureDragStartCallback? onVerticalDragStart, GestureDragUpdateCallback? onVerticalDragUpdate, GestureDragEndCallback? onVerticalDragEnd, GestureDragCancelCallback? onVerticalDragCancel, GestureDragDownCallback? onHorizontalDragDown, GestureDragStartCallback? onHorizontalDragStart, GestureDragUpdateCallback? onHorizontalDragUpdate, GestureDragEndCallback? onHorizontalDragEnd, GestureDragCancelCallback? onHorizontalDragCancel, GestureForcePressStartCallback? onForcePressStart, GestureForcePressPeakCallback? onForcePressPeak, GestureForcePressUpdateCallback? onForcePressUpdate, GestureForcePressEndCallback? onForcePressEnd, GestureDragDownCallback? onPanDown, GestureDragStartCallback? onPanStart, GestureDragUpdateCallback? onPanUpdate, GestureDragEndCallback? onPanEnd, GestureDragCancelCallback? onPanCancel, GestureScaleStartCallback? onScaleStart, GestureScaleUpdateCallback? onScaleUpdate, GestureScaleEndCallback? onScaleEnd, HitTestBehavior? behavior, bool excludeFromSemantics = false, DragStartBehavior dragStartBehavior = DragStartBehavior.start, bool trackpadScrollCausesScale = false, Offset trackpadScrollToScaleFactor = kDefaultTrackpadScrollToScaleFactor, Set<PointerDeviceKind>? supportedDevices}) → GestureDetector

Available on Widget, provided by the WidgetChainExt extension

用GestureDetector包裹当前组件

ignorePointer({Key? key, bool ignoring = true}) → IgnorePointer

Available on Widget, provided by the WidgetChainExt extension

用IgnorePointer包裹当前组件

inkWell({Key? key, GestureTapCallback? onTap, GestureTapDownCallback? onTapDown, GestureTapUpCallback? onTapUp, GestureTapCallback? onTapCancel, GestureTapCallback? onDoubleTap, GestureLongPressCallback? onLongPress, GestureTapCallback? onSecondaryTap, GestureTapUpCallback? onSecondaryTapUp, GestureTapDownCallback? onSecondaryTapDown, GestureTapCallback? onSecondaryTapCancel, ValueChanged<bool>? onHighlightChanged, ValueChanged<bool>? onHover, MouseCursor? mouseCursor, bool containedInkWell = false, BoxShape highlightShape = BoxShape.circle, double? radius, BorderRadius? borderRadius, ShapeBorder? customBorder, Color? focusColor, Color? hoverColor, Color? highlightColor, MaterialStateProperty<Color?>? overlayColor, Color? splashColor, InteractiveInkFeatureFactory? splashFactory, bool enableFeedback = true, bool excludeFromSemantics = false, FocusNode? focusNode, bool canRequestFocus = true, ValueChanged<bool>? onFocusChange, bool autofocus = false, MaterialStatesController? statesController, Duration? hoverDuration}) → InkWell

Available on Widget, provided by the WidgetChainExt extension

用InkWell包裹当前组件

margin(EdgeInsetsGeometry margin, {Key? key}) → Padding

Available on Widget, provided by the WidgetChainExt extension

用Padding包裹当前组件

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

offstage(bool offstage, {Key? key}) → Offstage

Available on Widget, provided by the WidgetChainExt extension

用Offstage包裹当前组件

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

Available on Widget, provided by the WidgetChainExt extension

用Opacity包裹当前组件

padding(EdgeInsetsGeometry padding, {Key? key}) → Padding

Available on Widget, provided by the WidgetChainExt extension

用Padding包裹当前组件

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

Available on Widget, provided by the WidgetChainExt extension

用Positioned包裹当前组件

repaintBoundary({Key? key}) → RepaintBoundary

Available on Widget, provided by the WidgetChainExt extension

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

Available on Widget, provided by the WidgetChainExt extension

singleChildScrollView({Key? key, Axis scrollDirection = Axis.vertical, bool reverse = false, EdgeInsetsGeometry? padding, bool? primary, ScrollPhysics? physics, ScrollController? controller, dynamic child, DragStartBehavior dragStartBehavior = DragStartBehavior.start, Clip clipBehavior = Clip.hardEdge, String? restorationId, ScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual}) → SingleChildScrollView

Available on Widget, provided by the WidgetChainExt extension

sizedBox({Key? key, double? width, double? height}) → SizedBox

Available on Widget, provided by the WidgetChainExt extension

tap(GestureTapCallback? onTap) → Widget

Available on Widget, provided by the WidgetChainExt extension

点击事件

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

visibility(bool visible, {Key? key, Widget replacement = const SizedBox.shrink(), bool maintainState = false, bool maintainAnimation = false, bool maintainSize = false, bool maintainSemantics = false, bool maintainInteractivity = false}) → Visibility

Available on Widget, provided by the WidgetChainExt extension

用Visibility包裹当前组件

widgetSpan({PlaceholderAlignment alignment = PlaceholderAlignment.bottom, TextBaseline? baseline, TextStyle? style}) → WidgetSpan

Available on Widget, provided by the WidgetChainExt extension

Operators

operator ==(Object other) → bool

The equality operator.

inherited