Flutter学习笔记：API

本文更新于2024-12-26，使用Flutter 3.3.3。

官方文档：https://api.flutter.dev或https://api.flutter-io.cn

dart:ui 【UI库】
- 枚举
  - TextDirection —— 文本方向
animation 【动画库】
- 类
- 枚举
  - AnimationStatus —— 动画状态
flutter_localizations 【多语言本地化库】
- 类
  - GlobalMaterialLocalizations —— Material风格组件的多语言本地化
  - GlobalWidgetsLocalizations —— 组件的多语言本地化
cupertino 【Cupertino（iOS）风格库】
driver_extension 【驱动扩展库】
- 函数
  - enableFlutterDriverExtension —— 启用Flutter驱动扩展
flutter_driver 【驱动库】
- 类
  - CommonFinders —— 普通查找器
  - FlutterDriver —— Flutter驱动
flutter_test 【测试库】
foundation 【基础库】
- 属性
  - debugPrint —— 调试打印
gestures 【手势库】
- 类
physics 【物理效果库】
material 【Material（Android）风格库】
painting 【绘图库】
- 类
- 枚举
path 【跨平台路径库】
- 函数
rendering 【渲染库】
scheduler 【调度库】
- 属性
services 【平台服务库】
- 类
- 枚举
  - TextInputAction —— 文本输入操作
widgets 【组件库】

import 'dart:ui';

枚举

TextDirection —— 文本方向

继承
Object > Enum > TextDirection
值
- rtl → const TextDirection：从右到左。
- ltr → const TextDirection：从左到右。

import 'package:flutter/animation.dart';

Flutter支持120FPS（Frames Per Second，帧每秒）的帧率。

类

AnimatedBuilder —— 动画创建器

可用于实现动画叠加，即交错动画。

继承
Object > DiagnosticableTree > Widget > StatefulWidget > AnimatedWidget > ListenableBuilder > AnimatedBuilder

构造函数

AnimatedBuilder({
	Key? key,
	required Listenable animation,
	required TransitionBuilder builder,
	Widget? child
})

Animation<T> —— 动画

一方面生成动画的值，另一方面用来得知动画的状态。但是无法通过它得知动画的具象，且和渲染无关。

继承
Object > Listenable > Animation
构造函数
```
Animation()
```
属性
- value → T：动画的值。
方法
- addListener(VoidCallback listener) → void：添加事件监听器。在动画的值发生变化时触发。
- addStatusListener(AnimationStatusListener listener) → void：添加状态监听器。在动画的状态发生变化时触发。

AnimationController —— 动画控制器

管理Animation。

继承
Object > Listenable > Animation<double> > AnimationController

构造函数

AnimationController({
	double? value,
	Duration? duration,
	Duration? reverseDuration,
	String? debugLabel,
	double lowerBound = 0.0,
	double upperBound = 1.0,
	AnimationBehavior animationBehavior = AnimationBehavior.normal,
	required TickerProvider vsync
})

vsync：垂直同步的区域。限制此区域在执行动画的区域内，可避免消耗过多资源。

属性
- duration ↔ Duration?：动画的持续时间。
方法
- dispose() → void：销毁动画。
- forward({double? from}) → TickerFuture：正向播放动画。
- reset() → void：重置动画至初始位置。
- reverse({double? from}) → TickerFuture：反向播放动画。
- stop({bool canceled = true}) → void：停止播放动画。

ColorTween —— 颜色补间

继承
Object > Animatable<Color?> > Tween<Color?> > ColorTween
构造函数
```
ColorTween({Color? begin, Color? end})
```

Curve —— 曲线

继承
Object > ParametricCurve<double> > Curve
构造函数
```
Curve()
```

CurvedAnimation —— 曲线动画/非线性动画

将动画的过程抽象成非线性曲线。

继承
Object > Listenable > Animation<double> > CurvedAnimation

构造函数

CurvedAnimation({
	required Animation<double> parent,
	required Curve curve,
	Curve? reverseCurve
})

Curves —— 曲线集

常量
- bounceIn → const Curve：气球跳跃式。
- ease → const Cubic
- linear → const Curve：线性。

Interval —— 时间间隔

可以用来定义动画在执行上的时间线顺序。

继承
Object > ParametricCurve<double> > Curve > Interval

构造函数

Interval(
	double begin,
	double end,
	{
	Curve curve = Curves.linear
	}
)

属性
- begin → double：起始时间点在动画时间轴的百分比。
- end → double：结束时间点在动画时间轴的百分比。

Locale —— 语系区域

构造函数

Locale(String _languageCode, [String? _countryCode])

Tween<T extends Object?> —— 补间

定义正在执行动画的对象所使用的数据范围内的值。

继承
Object > Animatable<T> > Tween
构造函数
```
Tween({
	T? begin,
	T? end
})
```
方法
- animate(Animation<double> parent) → Animation<T>：生成动画。

枚举

AnimationStatus —— 动画状态

值
- dismissed → const AnimationStatus
- forward → const AnimationStatus
- reverse → const AnimationStatus
- completed → const AnimationStatus

类

GlobalMaterialLocalizations —— Material风格组件的多语言本地化

常量
- delegate → const LocalizationsDelegate<MaterialLocalizations>

GlobalWidgetsLocalizations —— 组件的多语言本地化

常量
- delegate → const LocalizationsDelegate<WidgetsLocalizations>

import 'package:flutter/cupertino.dart';

与Material的类比关系：

Cupertino	Material
CupertinoApp	MaterialApp
CupertinoPageScaffold	Scaffold
CupertinoTabScaffold	Scaffold
CupertinoNavigationBar	AppBar
CupertinoTabBar	BottomNavigationBar
CupertinoAlertDialog	AlertDialog
CupertinoSlider	Slider

类

CupertinoActionSheet —— Cupertino设计风格的操作表

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoActionSheet

构造函数

CupertinoActionSheet({
	Key? key,
	Widget? title,
	Widget? message,
	List<Widget>? actions,
	ScrollController? messageScrollController,
	ScrollController? actionScrollController,
	Widget? cancelButton
})

属性
- actions → List<Widget>?：操作项列表。
- cancelButton → Widget?：取消按钮。
- message → Widget?：描述。
- title → Widget?：标题。

CupertinoActionSheetAction —— Cupertino设计风格的操作表的操作项

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoActionSheetAction

构造函数

CupertinoActionSheetAction({
	Key? key,
	required VoidCallback onPressed,
	bool isDefaultAction = false,
	bool isDestructiveAction = false,
	required Widget child
})

CupertinoActivityIndicator —— Cupertino设计风格的动作指示器

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoActivityIndicator

构造函数

CupertinoActivityIndicator({
	Key? key,
	Color? color,
	bool animating = true,
	double radius = _kDefaultIndicatorRadius
})

属性
- animating → bool：是否具有动画效果。默认为true。
- radius → double：半径。默认为10。

CupertinoAlertDialog —— Cupertino设计风格的提示框

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoAlertDialog

构造函数

CupertinoAlertDialog({
	Key? key,
	Widget? title,
	Widget? content,
	List<Widget> actions = const <Widget>[],
	ScrollController? scrollController,
	ScrollController? actionScrollController,
	Duration insetAnimationDuration = const Duration(milliseconds: 100),
	Curve insetAnimationCurve = Curves.decelerate
})

属性
- actions → List<Widget>：操作列表。不多于两个时水平排列，多余两个时垂直排列。
- content → Widget?：内容。
- title → Widget?：标题。

CupertinoApp —— Cupertino设计风格APP

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoApp

构造函数

CupertinoApp({
	Key? key,
	GlobalKey<NavigatorState>? navigatorKey,
	Widget? home,
	CupertinoThemeData? theme,
	Map<String,
	Widget Function(BuildContext)> routes = const <String, WidgetBuilder>{},
	String? initialRoute,
	RouteFactory? onGenerateRoute,
	InitialRouteListFactory? onGenerateInitialRoutes,
	RouteFactory? onUnknownRoute,
	NotificationListenerCallback<NavigationNotification>? onNavigationNotification,
	List<NavigatorObserver> navigatorObservers = const <NavigatorObserver>[],
	TransitionBuilder? builder,
	String title = '',
	GenerateAppTitle? onGenerateTitle,
	Color? color,
	Locale? locale,
	Iterable<LocalizationsDelegate>? localizationsDelegates,
	LocaleListResolutionCallback? localeListResolutionCallback,
	LocaleResolutionCallback? localeResolutionCallback,
	Iterable<Locale> supportedLocales = const <Locale>[Locale('en', 'US')],
	bool showPerformanceOverlay = false,
	bool checkerboardRasterCacheImages = false,
	bool checkerboardOffscreenLayers = false,
	bool showSemanticsDebugger = false,
	bool debugShowCheckedModeBanner = true,
	Map<ShortcutActivator, Intent>? shortcuts,
	Map<Type, Action<Intent>>? actions,
	String? restorationScopeId,
	ScrollBehavior? scrollBehavior,
	@Deprecated(
		'Remove this parameter as it is now ignored. '
		'CupertinoApp never introduces its own MediaQuery; the View widget takes care of that. '
		'This feature was deprecated after v3.7.0-29.0.pre.'
	)
	bool useInheritedMediaQuery = false})

CupertinoButton —— Cupertino设计风格的按钮

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoButton

构造函数

CupertinoButton({
	Key? key,
	required Widget child,
	EdgeInsetsGeometry? padding,
	Color? color,
	Color disabledColor = CupertinoColors.quaternarySystemFill,
	double? minSize = kMinInteractiveDimensionCupertino,
	double? pressedOpacity = 0.4,
	BorderRadius? borderRadius = const BorderRadius.all(Radius.circular(8.0)),
	AlignmentGeometry alignment = Alignment.center,
	Color? focusColor,
	FocusNode? focusNode,
	ValueChanged<bool>? onFocusChange,
	bool autofocus = false,
	required VoidCallback? onPressed
})

属性
- borderRadius → BorderRadius?：圆角的半径。仅在设置了color时生效。
- child → Widget：子组件。
- color → Color?：颜色。默认无颜色。
- disabledColor → Color：在不可用时的颜色。
- enabled → bool：是否可用。默认为false。可通过给onPressed赋值来使其可用。
- onPressed → VoidCallback?：点击时的回调。

CupertinoColors —— Cupertino设计风格的颜色集

CupertinoDatePicker —— Cupertino设计风格的日期时间选择器

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoDatePicker

构造函数

CupertinoDatePicker({
	Key? key,
	CupertinoDatePickerMode mode = CupertinoDatePickerMode.dateAndTime,
	required ValueChanged<DateTime> onDateTimeChanged,
	DateTime? initialDateTime,
	DateTime? minimumDate,
	DateTime? maximumDate,
	int minimumYear = 1,
	int? maximumYear,
	int minuteInterval = 1,
	bool use24hFormat = false,
	DatePickerDateOrder? dateOrder,
	Color? backgroundColor,
	bool showDayOfWeek = false,
	double itemExtent = _kItemExtent,
	SelectionOverlayBuilder? selectionOverlayBuilder
})

属性
- initialDateTime → DateTime：初始日期时间。
- onDateTimeChanged → ValueChanged<DateTime>：日期时间改变时的回调。
- use24hFormat → bool：是否使用24小时制。

CupertinoIcons —— Cupertino设计风格的图标集

CupertinoNavigationBar —— Cupertino设计风格的导航栏

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoNavigationBar

构造函数

CupertinoNavigationBar({
	Key? key,
	Widget? leading,
	bool automaticallyImplyLeading = true,
	bool automaticallyImplyMiddle = true,
	String? previousPageTitle,
	Widget? middle,
	Widget? trailing,
	Border? border = _kDefaultNavBarBorder,
	Color? backgroundColor,
	Brightness? brightness,
	EdgeInsetsDirectional? padding,
	bool transitionBetweenRoutes = true,
	Object heroTag = _defaultHeroTag
})

属性
- automaticallyImplyLeading → bool：是否自动生成左侧的返回按钮。默认为true。
- backgroundColor → Color?：背景色。
- leading → Widget?：导航栏开头的组件。
- middle → Widget?：导航栏中间的组件。
- previousPageTitle → String?：上一个页面的标题。在左侧返回按钮旁显示。
- trailing → Widget?：导航栏结尾的组件。

CupertinoPageRoute<T> —— Cupertino设计风格的页面路由

继承
Object > Route<T> > OverlayRoute<T> > TransitionRoute<T> > ModalRoute<T> > PageRoute<T> > CupertinoPageRoute

构造函数

CupertinoPageRoute({
	required WidgetBuilder builder,
	String? title,
	RouteSettings? settings,
	bool maintainState = true,
	bool fullscreenDialog = false,
	bool allowSnapshotting = true,
	bool barrierDismissible = false
})

CupertinoPageScaffold —— Cupertino设计风格的单页面脚手架

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoPageScaffold

构造函数

CupertinoPageScaffold({
	Key? key,
	ObstructingPreferredSizeWidget? navigationBar,
	Color? backgroundColor,
	bool resizeToAvoidBottomInset = true,
	required Widget child
})

属性
- backgroundColor → Color?：脚手架内所有组件的颜色。
- child → Widget：界面主要内容。
- navigationBar → ObstructingPreferredSizeWidget?：顶部导航栏。

CupertinoPicker —— Cupertino设计风格的选择器

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoPicker

构造函数

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
})

children：子组件列表。
looping：是否循环显示。

属性
- backgroundColor → Color?：背景色。
- itemExtent → double：每个项的高度。
- onSelectedItemChanged → ValueChanged<int>?：选中项变化时的回调。

CupertinoSlider —— Cupertino设计风格的滑块

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoSlider

构造函数

CupertinoSlider({
	Key? key,
	required double value,
	required ValueChanged<double>? onChanged,
	ValueChanged<double>? onChangeStart,
	ValueChanged<double>? onChangeEnd,
	double min = 0.0,
	double max = 1.0,
	int? divisions,
	Color? activeColor,
	Color thumbColor = CupertinoColors.white
})

CupertinoTabBar —— Cupertino设计风格的选项卡栏

继承
Object > DiagnosticableTree > Widget > StatelessWidget > CupertinoTabBar

构造函数

CupertinoTabBar({
	Key? key,
	required List<BottomNavigationBarItem> items,
	ValueChanged<int>? onTap,
	int currentIndex = 0,
	Color? backgroundColor,
	Color? activeColor,
	Color inactiveColor = _kDefaultTabBarInactiveColor,
	double iconSize = 30.0,
	double height = _kTabBarHeight,
	Border? border = const Border(top: BorderSide(color: _kDefaultTabBarBorderColor, width: 0.0))
})

属性
- activeColor → Color?：选中选项卡的颜色。
- currentIndex → int：选中选项卡的下标。
- inactiveColor → Color：未选中选项卡的颜色。
- items → List<BottomNavigationBarItem>：描述选项卡的样式和个数。
- onTap → ValueChanged<int>?：选项卡被点击的回调。

CupertinoTabScaffold —— Cupertino设计风格的选项卡页面脚手架

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoTabScaffold

构造函数

CupertinoTabScaffold({
	Key? key,
	required CupertinoTabBar tabBar,
	required IndexedWidgetBuilder tabBuilder,
	CupertinoTabController? controller,
	Color? backgroundColor,
	bool resizeToAvoidBottomInset = true,
	String? restorationId
})

属性
- tabBar → CupertinoTabBar：选项卡栏。
- tabBuilder → IndexedWidgetBuilder：选项卡页面内容构建器。

CupertinoTabView —— Cupertino设计风格的选项卡页面内容视图

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoTabView

构造函数

CupertinoTabView({
	Key? key,
	WidgetBuilder? builder,
	GlobalKey<NavigatorState>? navigatorKey,
	String? defaultTitle,
	Map<String,
	WidgetBuilder>? routes,
	RouteFactory? onGenerateRoute,
	RouteFactory? onUnknownRoute,
	List<NavigatorObserver> navigatorObservers = const <NavigatorObserver>[],
	String? restorationScopeId
})

builder → WidgetBuilder?：内容构建器。

CupertinoTimerPicker —— Cupertino设计风格的定时器选择器

可选范围是0至23小时59分59秒。

继承
Object > DiagnosticableTree > Widget > StatefulWidget > CupertinoTimerPicker

构造函数

CupertinoTimerPicker({
	Key? key,
	CupertinoTimerPickerMode mode = CupertinoTimerPickerMode.hms,
	Duration initialTimerDuration = Duration.zero,
	int minuteInterval = 1,
	int secondInterval = 1,
	AlignmentGeometry alignment = Alignment.center,
	Color? backgroundColor,
	double itemExtent = _kItemExtent,
	required ValueChanged<Duration> onTimerDurationChanged,
	SelectionOverlayBuilder? selectionOverlayBuilder
})

属性
- initialTimerDuration → Duration：初始定时值。
- mode → CupertinoTimerPickerMode：定时器模式。
- onTimerDurationChanged → ValueChanged<Duration>：定时值改变时的回调。

枚举

CupertinoTimerPickerMode —— Cupertino设计风格的定时器选择器模式

hm → const CupertinoTimerPickerMode：时分。
ms → const CupertinoTimerPickerMode：分秒。
hms → const CupertinoTimerPickerMode：时分秒。

函数

showCupertinoDialog —— 展示Cupertino设计风格的对话框

Future<T?> showCupertinoDialog<T>({
	required BuildContext context,
	required WidgetBuilder builder,
	String? barrierLabel,
	bool useRootNavigator = true,
	bool barrierDismissible = false,
	RouteSettings? routeSettings,
	Offset? anchorPoint,
})

showCupertinoModalPopup<T> —— 展示Cupertino设计风格的模态弹出对话框

Future<T?> showCupertinoModalPopup<T>({
	required BuildContext context,
	required WidgetBuilder builder,
	ImageFilter? filter,
	Color barrierColor = kCupertinoModalBarrierColor,
	bool barrierDismissible = true,
	bool useRootNavigator = true,
	bool semanticsDismissible = false,
	RouteSettings? routeSettings,
	Offset? anchorPoint,
})

函数

enableFlutterDriverExtension —— 启用Flutter驱动扩展

void enableFlutterDriverExtension({
	DataHandler? handler,
	bool silenceErrors = false,
	bool enableTextEntryEmulation = true,
	List<FinderExtension>? finders,
	List<CommandExtension>? commands,
})

类

CommonFinders —— 普通查找器

方法
- byValueKey(dynamic key) → SerializableFinder

FlutterDriver —— Flutter驱动

构造函数

FlutterDriver.connectedTo({FlutterWebConnection? webConnection, VmService? serviceClient, Isolate? appIsolate})

方法
- close() → Future<void>
- getText(SerializableFinder finder, {Duration? timeout}) → Future<String>
- tap(SerializableFinder finder, {Duration? timeout}) → Future<void>

类

CommonFinders —— 普通查找器

方法
- byIcon(IconData icon, {bool skipOffstage = true}) → Finder
- text(String text, {bool findRichText = false, bool skipOffstage = true}) → Finder

WidgetTester —— 组件测试类

方法
- pump([Duration? duration, EnginePhase phase = EnginePhase.sendSemanticsUpdate]) → Future<void>：重建组件。
- pumpWidget(Widget widget, {Duration? duration, EnginePhase phase = EnginePhase.sendSemanticsUpdate, bool wrapWithView = true}) → Future<void>：在后台创建组件。
- tap(FinderBase<Element> finder, {int? pointer, int buttons = kPrimaryButton, bool warnIfMissed = true, PointerDeviceKind kind = PointerDeviceKind.touch}) → Future<void>：模拟点击。

常量

find —— 查找器

find → const CommonFinders

findsNothing —— 查找不到组件

findsNothing → const Matcher

findsOneWidget —— 查找到一个组件

findsOneWidget → const Matcher

函数

expect —— 测试结果期望

void expect(
	dynamic actual,
	dynamic matcher, {
	String? reason,
	dynamic skip,
})

group —— 注册测试组

@isTestGroup
void group(
	Object description,
	void body(), {
	dynamic skip,
	int? retry,
})

setUpAll —— 注册在所有测试执行前的动作

void setUpAll( dynamic body() )

tearDownAll —— 注册在所有测试执行后的动作

void tearDownAll( dynamic body() )

test —— 注册单元测试

@isTest
void test(
	Object description,
	dynamic body(), {
	String? testOn,
	Timeout? timeout,
	dynamic skip,
	dynamic tags,
	Map<String, dynamic>? onPlatform,
	int? retry,
})

testWidgets —— 注册组件测试

@isTest
void testWidgets(
	String description,
	WidgetTesterCallback callback, {
	bool? skip,
	Timeout? timeout,
	bool semanticsEnabled = true,
	TestVariant<Object?> variant = const DefaultTestVariant(),
	dynamic tags,
	int? retry,
	LeakTesting? experimentalLeakTesting,
})

自动导入。

属性

debugPrint —— 调试打印

debugPrint ↔ DebugPrintCallback

import 'package:flutter/gestures.dart';

类

GestureArenaMember —— 手势竞技员

构造函数
```
GestureArenaMember()
```

GestureRecognizer —— 手势识别器

内部结合Listener实现。

继承
Object > GestureArenaMember > GestureRecognizer

构造函数

GestureRecognizer({
	Object? debugOwner,
	Set<PointerDeviceKind>? supportedDevices,
	AllowedButtonsFilter allowedButtonsFilter = _defaultButtonAcceptBehavior
})

PointerEvent —— 指向事件

属性
- orientation → double：移动方向。
- pressure → double：压力。

import 'package:flutter/physics.dart';

此库是对animation库的再封装。

import 'package:flutter/material.dart';

类

AboutListTile —— 展示“关于”信息的列表瓦片

继承
Object > DiagnosticableTree > Widget > StatelessWidget > AboutListTile

构造函数

AboutListTile({
	Key? key,
	Widget? icon,
	Widget? child,
	String? applicationName,
	String? applicationVersion,
	Widget? applicationIcon,
	String? applicationLegalese,
	List<Widget>? aboutBoxChildren,
	bool? dense
})

AlertDialog —— 提示框

继承
Object > DiagnosticableTree > Widget > StatelessWidget > AlertDialog

构造函数

AlertDialog({
	Key? key,
	Widget? icon,
	EdgeInsetsGeometry? iconPadding,
	Color? iconColor,
	Widget? title,
	EdgeInsetsGeometry? titlePadding,
	TextStyle? titleTextStyle,
	Widget? content,
	EdgeInsetsGeometry? contentPadding,
	TextStyle? contentTextStyle,
	List<Widget>? actions,
	EdgeInsetsGeometry? actionsPadding,
	MainAxisAlignment? actionsAlignment,
	OverflowBarAlignment? actionsOverflowAlignment,
	VerticalDirection? actionsOverflowDirection,
	double? actionsOverflowButtonSpacing,
	EdgeInsetsGeometry? buttonPadding,
	Color? backgroundColor,
	double? elevation,
	Color? shadowColor,
	Color? surfaceTintColor,
	String? semanticLabel,
	EdgeInsets? insetPadding,
	Clip? clipBehavior,
	ShapeBorder? shape,
	AlignmentGeometry? alignment,
	bool scrollable = false
})

属性
- actions → List<Widget>?：操作列表。总是横向排列。
- content → Widget?：提示内容。
- title → Widget?：标题。

AppBar —— 应用程序栏

继承
Object > DiagnosticableTree > Widget > StatefulWidget > AppBar

构造函数

AppBar({
	Key? key,
	Widget? leading,
	bool automaticallyImplyLeading = true,
	Widget? title,
	List<Widget>? actions,
	Widget? flexibleSpace,
	PreferredSizeWidget? bottom,
	double? elevation,
	double? scrolledUnderElevation,
	ScrollNotificationPredicate notificationPredicate = defaultScrollNotificationPredicate,
	Color? shadowColor,
	Color? surfaceTintColor,
	ShapeBorder? shape,
	Color? backgroundColor,
	Color? foregroundColor,
	IconThemeData? iconTheme,
	IconThemeData? actionsIconTheme,
	bool primary = true,
	bool? centerTitle,
	bool excludeHeaderSemantics = false,
	double? titleSpacing,
	double toolbarOpacity = 1.0,
	double bottomOpacity = 1.0,
	double? toolbarHeight,
	double? leadingWidth,
	TextStyle? toolbarTextStyle,
	TextStyle? titleTextStyle,
	SystemUiOverlayStyle? systemOverlayStyle,
	bool forceMaterialTransparency = false,
	Clip? clipBehavior
})

属性
- actions → List<Widget>?：标题之后的组件列表。
- bottom → PreferredSizeWidget?：底部组件。
- centerTitle → bool?：标题是否居中。如为false，则靠近起点位置。
- leading → Widget?：左上角组件。位于标题之前。
- title → Widget?：标题。

BottomNavigationBar —— 底部导航栏

继承
Object > DiagnosticableTree > Widget > StatefulWidget > BottomNavigationBar

构造函数

BottomNavigationBar({
	Key? key,
	required List<BottomNavigationBarItem> items,
	ValueChanged<int>? onTap,
	int currentIndex = 0,
	double? elevation,
	BottomNavigationBarType? type,
	Color? fixedColor,
	Color? backgroundColor,
	double iconSize = 24.0,
	Color? selectedItemColor,
	Color? unselectedItemColor,
	IconThemeData? selectedIconTheme,
	IconThemeData? unselectedIconTheme,
	double selectedFontSize = 14.0,
	double unselectedFontSize = 12.0,
	TextStyle? selectedLabelStyle,
	TextStyle? unselectedLabelStyle,
	bool? showSelectedLabels,
	bool? showUnselectedLabels,
	MouseCursor? mouseCursor,
	bool? enableFeedback,
	BottomNavigationBarLandscapeLayout? landscapeLayout,
	bool useLegacyColorScheme = true
})

属性
- currentIndex → int：选中选项卡的下标。
- items → List<BottomNavigationBarItem>：描述选项卡的样式和个数。
- onTap → ValueChanged<int>?：选项卡被点击的回调。

Card —— 卡片

内容不允许滚动。

继承
Object > DiagnosticableTree > Widget > StatelessWidget > Card

构造函数

Card({
	Key? key,
	Color? color,
	Color? shadowColor,
	Color? surfaceTintColor,
	double? elevation,
	ShapeBorder? shape,
	bool borderOnForeground = true,
	EdgeInsetsGeometry? margin,
	Clip? clipBehavior,
	Widget? child,
	bool semanticContainer = true
})

属性
- child → Widget?：子组件。
- shape → ShapeBorder?：形状。

Checkbox —— 复选框

继承
Object > DiagnosticableTree > Widget > StatefulWidget > Checkbox

构造函数

Checkbox({
	Key? key,
	required bool? value,
	bool tristate = false,
	required ValueChanged<bool?>? onChanged,
	MouseCursor? mouseCursor,
	Color? activeColor,
	MaterialStateProperty<Color?>? fillColor,
	Color? checkColor,
	Color? focusColor,
	Color? hoverColor,
	MaterialStateProperty<Color?>? overlayColor,
	double? splashRadius,
	MaterialTapTargetSize? materialTapTargetSize,
	VisualDensity? visualDensity,
	FocusNode? focusNode,
	bool autofocus = false,
	OutlinedBorder? shape, 
	BorderSide? side,
	bool isError = false,
	String? semanticLabel
})

Chip —— 碎片/标签

继承
Object > DiagnosticableTree > Widget > StatelessWidget > Chip

构造函数

Chip({
	Key? key,
	Widget? avatar,
	required Widget label,
	TextStyle? labelStyle,
	EdgeInsetsGeometry? labelPadding,
	Widget? deleteIcon,
	VoidCallback? onDeleted,
	Color? deleteIconColor,
	String? deleteButtonTooltipMessage,
	BorderSide? side,
	OutlinedBorder? shape,
	Clip clipBehavior = Clip.none, 
	FocusNode? focusNode,
	bool autofocus = false,
	MaterialStateProperty<Color?>? color,
	Color? backgroundColor,
	EdgeInsetsGeometry? padding,
	VisualDensity? visualDensity,
	MaterialTapTargetSize? materialTapTargetSize,
	double? elevation,
	Color? shadowColor,
	Color? surfaceTintColor,
	IconThemeData? iconTheme,
	BoxConstraints? avatarBoxConstraints,
	BoxConstraints? deleteIconBoxConstraints,
	ChipAnimationStyle? chipAnimationStyle
})

属性
- avatar → Widget?：主体内容之前的小图标。
- backgroundColor → Color?：背景色。
- deleteButtonTooltipMessage → String?：当删除图标长按时的提示内容。
- deleteIcon → Widget?：右侧删除图标。
- deleteIconColor → Color?：右侧删除图标的颜色。
- label → Widget：主体内容。
- onDeleted → VoidCallback?：被删除时的回调。
- shape → OutlinedBorder?：形状。

CircleAvatar —— 圆形头像

继承
Object > DiagnosticableTree > Widget > StatelessWidget > CircleAvatar

构造函数

CircleAvatar({
	Key? key,
	Widget? child,
	Color? backgroundColor,
	ImageProvider<Object>? backgroundImage,
	ImageProvider<Object>? foregroundImage,
	ImageErrorListener? onBackgroundImageError,
	ImageErrorListener? onForegroundImageError,
	Color? foregroundColor,
	double? radius,
	double? minRadius,
	double? maxRadius
})

CircularProgressIndicator —— 圆形进度条

继承
Object > DiagnosticableTree > Widget StatefulWidget > ProgressIndicator > CircularProgressIndicator

构造函数

CircularProgressIndicator({
	Key? key,
	double? value,
	Color? backgroundColor,
	Color? color,
	Animation<Color?>? valueColor,
	double strokeWidth = 4.0,
	double strokeAlign = strokeAlignCenter,
	String? semanticsLabel,
	String? semanticsValue,
	StrokeCap? strokeCap
})

属性
- value → double?：当前进度值。范围从0到1。如为null，则只显示动画效果。

Colors —— 颜色集

Divider —— 分隔线

继承
Object > DiagnosticableTree > Widget > StatelessWidget > Divider

构造函数

Divider({
	Key? key,
	double? height,
	double? thickness,
	double? indent,
	double? endIndent,
	Color? color
})

Drawer —— 抽屉

继承
Object > DiagnosticableTree > Widget > StatelessWidget > Drawer

构造函数

Drawer({
	Key? key,
	Color? backgroundColor,
	double? elevation,
	Color? shadowColor,
	Color? surfaceTintColor,
	ShapeBorder? shape,
	double? width,
	Widget? child,
	String? semanticLabel,
	Clip? clipBehavior
})

DrawerHeader —— 抽屉头

继承
Object > DiagnosticableTree > Widget > StatelessWidget > DrawerHeader

构造函数

DrawerHeader({
	Key? key,
	Decoration? decoration,
	EdgeInsetsGeometry? margin = const EdgeInsets.only(bottom: 8.0),
	EdgeInsetsGeometry padding = const EdgeInsets.fromLTRB(16.0, 16.0, 16.0, 8.0),
	Duration duration = const Duration(milliseconds: 250),
	Curve curve = Curves.fastOutSlowIn,
	required Widget? child
})

ElevatedButton —— 突起按钮

继承
Object > DiagnosticableTree > Widget > StatefulWidget > ButtonStyleButton > ElevatedButton

构造函数

ElevatedButton({
	Key? key,
	required VoidCallback? onPressed,
	VoidCallback? onLongPress,
	ValueChanged<bool>? onHover,
	ValueChanged<bool>? onFocusChange,
	ButtonStyle? style,
	FocusNode? focusNode,
	bool autofocus = false,
	Clip? clipBehavior,
	MaterialStatesController? statesController,
	required Widget? child,
	IconAlignment iconAlignment = IconAlignment.start
})

ExpansionPanel —— 可展开面板

构造函数

ExpansionPanel({
	required ExpansionPanelHeaderBuilder headerBuilder,
	required Widget body,
	bool isExpanded = false,
	bool canTapOnHeader = false,
	Color? backgroundColor,
	Color? splashColor,
	Color? highlightColor
})

属性
- body → Widget：展开的内容。
- headerBuilder → ExpansionPanelHeaderBuilder：标头构建器。
- isExpanded → bool：是否展开。

ExpansionPanelList —— 可展开面板列表

继承
Object > DiagnosticableTree > Widget > StatefulWidget > ExpansionPanelList

构造函数

ExpansionPanelList({
	Key? key,
	List<ExpansionPanel> children = const <ExpansionPanel>[],
	ExpansionPanelCallback? expansionCallback,
	Duration animationDuration = kThemeAnimationDuration,
	EdgeInsets expandedHeaderPadding = _kPanelHeaderExpandedDefaultPadding,
	Color? dividerColor,
	double elevation = 2,
	Color? expandIconColor,
	double materialGapSize = 16.0
})

属性
- children → List<ExpansionPanel>：子组件列表。
- expansionCallback → ExpansionPanelCallback?：每个子组件展开/缩起时的回调。

FloatingActionButton —— 浮动操作按钮

继承
Object > DiagnosticableTree > Widget > StatelessWidget > FloatingActionButton

构造函数

FloatingActionButton({
	Key? key,
	Widget? child,
	String? tooltip,
	Color? foregroundColor,
	Color? backgroundColor,
	Color? focusColor,
	Color? hoverColor,
	Color? splashColor,
	Object? heroTag = const _DefaultHeroTag(),
	double? elevation,
	double? focusElevation,
	double? hoverElevation,
	double? highlightElevation,
	double? disabledElevation,
	required VoidCallback? onPressed,
	MouseCursor? mouseCursor,
	bool mini = false,
	ShapeBorder? shape,
	Clip clipBehavior = Clip.none,
	FocusNode? focusNode,
	bool autofocus = false,
	MaterialTapTargetSize? materialTapTargetSize,
	bool isExtended = false,
	bool? enableFeedback
})

FloatingActionButton.extended({
	Key? key,
	String? tooltip,
	Color? foregroundColor,
	Color? backgroundColor,
	Color? focusColor,
	Color? hoverColor,
	Object? heroTag = const _DefaultHeroTag(),
	double? elevation,
	double? focusElevation,
	double? hoverElevation,
	Color? splashColor,
	double? highlightElevation,
	double? disabledElevation,
	required VoidCallback? onPressed,
	MouseCursor? mouseCursor = SystemMouseCursors.click,
	ShapeBorder? shape,
	bool isExtended = true,
	MaterialTapTargetSize? materialTapTargetSize,
	Clip clipBehavior = Clip.none,
	FocusNode? focusNode,
	bool autofocus = false,
	double? extendedIconLabelSpacing,
	EdgeInsetsGeometry? extendedPadding,
	TextStyle? extendedTextStyle,
	Widget? icon,
	required Widget label,
	bool? enableFeedback
})

属性
- child → Widget?：子组件。
- heroTag → Object?：共享元素过渡动画所使用的标签。
- mini → bool：控制按钮的大小。
- isExtended → bool：是否是拉长的按钮。
- onPressed → VoidCallback?：点击回调。

MaterialApp —— Material设计风格APP

必需由MaterialApp包装Material设计风格的组件。

继承
Object > DiagnosticableTree > Widget > StatefulWidget > MaterialApp

构造函数

MaterialApp({
	Key? key,
	GlobalKey<NavigatorState>? navigatorKey,
	GlobalKey<ScaffoldMessengerState>? scaffoldMessengerKey,
	Widget? home,
	Map<String,
	WidgetBuilder> routes = const <String, WidgetBuilder>{},
	String? initialRoute,
	RouteFactory? onGenerateRoute,
	InitialRouteListFactory? onGenerateInitialRoutes,
	RouteFactory? onUnknownRoute,
	NotificationListenerCallback<NavigationNotification>? onNavigationNotification,
	List<NavigatorObserver> navigatorObservers = const <NavigatorObserver>[],
	TransitionBuilder? builder,
	String title = '',
	GenerateAppTitle? onGenerateTitle,
	Color? color,
	ThemeData? theme,
	ThemeData? darkTheme,
	ThemeData? highContrastTheme,
	ThemeData? highContrastDarkTheme,
	ThemeMode? themeMode = ThemeMode.system,
	Duration themeAnimationDuration = kThemeAnimationDuration,
	Curve themeAnimationCurve = Curves.linear,
	Locale? locale,
	Iterable<LocalizationsDelegate>? localizationsDelegates,
	LocaleListResolutionCallback? localeListResolutionCallback,
	LocaleResolutionCallback? localeResolutionCallback,
	Iterable<Locale> supportedLocales = const <Locale>[Locale('en', 'US')],
	bool debugShowMaterialGrid = false,
	bool showPerformanceOverlay = false,
	bool checkerboardRasterCacheImages = false,
	bool checkerboardOffscreenLayers = false,
	bool showSemanticsDebugger = false,
	bool debugShowCheckedModeBanner = true,
	Map<ShortcutActivator, Intent>? shortcuts,
	Map<Type, Action<Intent>>? actions,
	String? restorationScopeId,
	ScrollBehavior? scrollBehavior,
	@Deprecated(
		'Remove this parameter as it is now ignored. '
		'MaterialApp never introduces its own MediaQuery; the View widget takes care of that. '
		'This feature was deprecated after v3.7.0-29.0.pre.'
	)
	bool useInheritedMediaQuery = false,
	AnimationStyle? themeAnimationStyle
})

theme：APP的主题。

属性
- color → Color?：应用图标的颜色，显示在系统的最近任务视图中。
- debugShowCheckedModeBanner → bool：调试模式下是否显示右上角的“DEBUG”条幅。发布模式下忽略此字段，总是不显示。
- debugShowMaterialGrid → bool：是否显示基线网格。
- home → Widget?：APP主界面。
- localeListResolutionCallback → LocaleListResolutionCallback?：选择语系区域时的回调。
- localizationsDelegates → Iterable<LocalizationsDelegate>?：多语言本地化代理列表。
- onGenerateTitle → GenerateAppTitle?
- routes → Map<String, WidgetBuilder>?：页面跳转静态定义路由。
- showPerformanceOverlay → bool：是否显示性能图表。
- showSemanticsDebugger → bool：是否启用语义调试。
- supportedLocales → Iterable<Locale>：支持的语系区域列表。
- title → String：APP的标题。通常显示在系统的最近任务视图中。

MaterialButton —— Material设计风格按钮

继承
Object > DiagnosticableTree > Widget > StatelessWidget > MaterialButton

构造函数

MaterialButton({
	Key? key,
	required VoidCallback? onPressed,
	VoidCallback? onLongPress,
	ValueChanged<bool>? onHighlightChanged,
	MouseCursor? mouseCursor,
	ButtonTextTheme? textTheme,
	Color? textColor,
	Color? disabledTextColor,
	Color? color,
	Color? disabledColor,
	Color? focusColor,
	Color? hoverColor,
	Color? highlightColor,
	Color? splashColor,
	Brightness? colorBrightness,
	double? elevation,
	double? focusElevation,
	double? hoverElevation,
	double? highlightElevation,
	double? disabledElevation,
	EdgeInsetsGeometry? padding,
	VisualDensity? visualDensity,
	ShapeBorder? shape,
	Clip clipBehavior = Clip.none,
	FocusNode? focusNode,
	bool autofocus = false,
	MaterialTapTargetSize? materialTapTargetSize,
	Duration? animationDuration,
	double? minWidth,
	double? height,
	bool enableFeedback = true,
	Widget? child
})

MaterialPageRoute<T> —— Material设计风格页面的路由

继承
Object > Route<T> > OverlayRoute<T> > TransitionRoute<T> > ModalRoute<T> > PageRoute<T> > MaterialPageRoute

构造函数

MaterialPageRoute({
	required WidgetBuilder builder,
	RouteSettings? settings,
	bool? requestFocus,
	bool maintainState = true,
	bool fullscreenDialog = false,
	bool allowSnapshotting = true,
	bool barrierDismissible = false
})

IconButton —— 图标按钮

点击时产生圆形背景和水波纹效果。

继承
Object > DiagnosticableTree > Widget > StatelessWidget > IconButton

构造函数

IconButton({
	Key? key,
	double? iconSize,
	VisualDensity? visualDensity,
	EdgeInsetsGeometry? padding,
	AlignmentGeometry? alignment,
	double? splashRadius,
	Color? color,
	Color? focusColor,
	Color? hoverColor,
	Color? highlightColor,
	Color? splashColor,
	Color? disabledColor,
	required VoidCallback? onPressed,
	MouseCursor? mouseCursor,
	FocusNode? focusNode,
	bool autofocus = false,
	String? tooltip,
	bool? enableFeedback,
	BoxConstraints? constraints,
	ButtonStyle? style,
	bool? isSelected,
	Widget? selectedIcon,
	required Widget icon
})

属性
- disabledColor → Color?
- highlightColor → Color?
- icon → Widget：图标。
- iconSize → double?：图标大小。
- onPressed → VoidCallback?：点击回调。

Icons —— 图标集

常量
- phone → const IconData：电话图标。

InkWell —— 水波纹

点击产生水波纹效果。

继承
Object > DiagnosticableTree > Widget > StatelessWidget > InkResponse > InkWell

构造函数

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

InputDecoration —— 输入装饰

构造函数

InputDecoration({
	Widget? icon,
	Color? iconColor,
	Widget? label,
	String? labelText,
	TextStyle? labelStyle,
	TextStyle? floatingLabelStyle,
	Widget? helper,
	String? helperText,
	TextStyle? helperStyle,
	int? helperMaxLines,
	String? hintText,
	TextStyle? hintStyle,
	TextDirection? hintTextDirection,
	int? hintMaxLines,
	Duration? hintFadeDuration,
	Widget? error,
	String? errorText,
	TextStyle? errorStyle,
	int? errorMaxLines,
	FloatingLabelBehavior? floatingLabelBehavior,
	FloatingLabelAlignment? floatingLabelAlignment,
	bool? isCollapsed,
	bool? isDense,
	EdgeInsetsGeometry? contentPadding,
	Widget? prefixIcon,
	BoxConstraints? prefixIconConstraints,
	Widget? prefix,
	String? prefixText,
	TextStyle? prefixStyle,
	Color? prefixIconColor,
	Widget? suffixIcon,
	Widget? suffix,
	String? suffixText,
	TextStyle? suffixStyle,
	Color? suffixIconColor,
	BoxConstraints? suffixIconConstraints,
	Widget? counter,
	String? counterText,
	TextStyle? counterStyle,
	bool? filled,
	Color? fillColor,
	Color? focusColor,
	Color? hoverColor,
	InputBorder? errorBorder,
	InputBorder? focusedBorder,
	InputBorder? focusedErrorBorder,
	InputBorder? disabledBorder,
	InputBorder? enabledBorder,
	InputBorder? border,
	bool enabled = true,
	String? semanticCounterText,
	bool? alignLabelWithHint,
	BoxConstraints? constraints
})

属性
- hintText → String?：提示文本。
- labelText → String?：标题文本。
- prefixIcon → Widget?：首部图标。

LinearProgressIndicator —— 水平进度条

继承
Object > DiagnosticableTree > Widget > StatefulWidget > ProgressIndicator > LinearProgressIndicator

构造函数

LinearProgressIndicator({
	Key? key,
	double? value,
	Color? backgroundColor,
	Color? color,
	Animation<Color?>? valueColor,
	double? minHeight,
	String? semanticsLabel,
	String? semanticsValue,
	BorderRadiusGeometry borderRadius = BorderRadius.zero
})

属性
- value → double?：当前进度值。范围从0到1。如为null，则只显示动画效果。

ListTile —— 列表瓦片

继承
Object > DiagnosticableTree > Widget > StatelessWidget > ListTile

构造函数

ListTile({
	Key? key,
	Widget? leading,
	Widget? title,
	Widget? subtitle,
	Widget? trailing,
	bool isThreeLine = false,
	bool? dense,
	VisualDensity? visualDensity,
	ShapeBorder? shape,
	ListTileStyle? style,
	Color? selectedColor,
	Color? iconColor,
	Color? textColor,
	TextStyle? titleTextStyle,
	TextStyle? subtitleTextStyle,
	TextStyle? leadingAndTrailingTextStyle,
	EdgeInsetsGeometry? contentPadding,
	bool enabled = true,
	GestureTapCallback? onTap,
	GestureLongPressCallback? onLongPress,
	ValueChanged<bool>? onFocusChange,
	MouseCursor? mouseCursor,
	bool selected = false,
	Color? focusColor,
	Color? hoverColor,
	Color? splashColor,
	FocusNode? focusNode,
	bool autofocus = false,
	Color? tileColor,
	Color? selectedTileColor,
	bool? enableFeedback,
	double? horizontalTitleGap,
	double? minVerticalPadding,
	double? minLeadingWidth,
	double? minTileHeight,
	ListTileTitleAlignment? titleAlignment
})

OutlinedButton —— 线框按钮

未点击时有浅浅的边框，背景透明；点击时边框亮起，显示背景色并伴有水波纹扩散。

继承
Object > DiagnosticableTree > Widget > StatefulWidget > ButtonStyleButton > OutlinedButton

构造函数

OutlinedButton({
	Key? key,
	required VoidCallback? onPressed,
	VoidCallback? onLongPress,
	ValueChanged<bool>? onHover,
	ValueChanged<bool>? onFocusChange,
	ButtonStyle? style,
	FocusNode? focusNode,
	bool autofocus = false,
	Clip? clipBehavior,
	MaterialStatesController? statesController,
	required Widget? child,
	IconAlignment iconAlignment = IconAlignment.start
})

PopupMenuButton<T> —— 弹出式菜单按钮

继承
Object > DiagnosticableTree > Widget > StatefulWidget > PopupMenuButton

构造函数

PopupMenuButton({
	Key? key,
	required PopupMenuItemBuilder<T> itemBuilder,
	T? initialValue,
	VoidCallback? onOpened,
	PopupMenuItemSelected<T>? onSelected,
	PopupMenuCanceled? onCanceled,
	String? tooltip,
	double? elevation,
	Color? shadowColor,
	Color? surfaceTintColor,
	EdgeInsetsGeometry padding = const EdgeInsets.all(8.0),
	EdgeInsetsGeometry? menuPadding,
	Widget? child,
	double? splashRadius,
	Widget? icon,
	double? iconSize,
	Offset offset = Offset.zero,
	bool enabled = true,
	ShapeBorder? shape,
	Color? color,
	Color? iconColor,
	bool? enableFeedback,
	BoxConstraints? constraints,
	PopupMenuPosition? position,
	Clip clipBehavior = Clip.none,
	bool useRootNavigator = false,
	AnimationStyle? popUpAnimationStyle,
	RouteSettings? routeSettings,
	ButtonStyle? style
})

属性
- child → Widget?：子组件。
- itemBuilder → PopupMenuItemBuilder<T>：弹出式菜单项构建器。
- onCanceled → PopupMenuCanceled?：弹出式菜单关闭时的回调。只在没有选中菜单项时运行。
- onSelected → PopupMenuItemSelected<T>?：菜单项被选中后的回调。

PopupMenuItem<T> —— 弹出式菜单项

继承
Object > DiagnosticableTree > Widget > StatefulWidget > PopupMenuEntry<T> > PopupMenuItem

构造函数

PopupMenuItem({
	Key? key,
	T? value,
	VoidCallback? onTap,
	bool enabled = true,
	double height = kMinInteractiveDimension,
	EdgeInsets? padding,
	TextStyle? textStyle,
	MaterialStateProperty<TextStyle?>? labelTextStyle,
	MouseCursor? mouseCursor,
	required Widget? child
})

Radio<T> —— 单选框

继承
Object > DiagnosticableTree > Widget > StatefulWidget > Radio

构造函数

Radio({
	Key? key,
	required T value,
	required T? groupValue,
	required ValueChanged<T?>? onChanged,
	MouseCursor? mouseCursor,
	bool toggleable = false,
	Color? activeColor,
	MaterialStateProperty<Color?>? fillColor,
	Color? focusColor,
	Color? hoverColor,
	MaterialStateProperty<Color?>? overlayColor,
	double? splashRadius,
	MaterialTapTargetSize? materialTapTargetSize,
	VisualDensity? visualDensity,
	FocusNode? focusNode,
	bool autofocus = false
})

Scaffold —— 脚手架

继承
Object > DiagnosticableTree > Widget > StatefulWidget > Scaffold

构造函数

Scaffold({
	Key? key,
	PreferredSizeWidget? appBar,
	Widget? body,
	Widget? floatingActionButton,
	FloatingActionButtonLocation? floatingActionButtonLocation,
	FloatingActionButtonAnimator? floatingActionButtonAnimator,
	List<Widget>? persistentFooterButtons,
	AlignmentDirectional persistentFooterAlignment = AlignmentDirectional.centerEnd,
	Widget? drawer,
	DrawerCallback? onDrawerChanged,
	Widget? endDrawer,
	DrawerCallback? onEndDrawerChanged,
	Widget? bottomNavigationBar,
	Widget? bottomSheet,
	Color? backgroundColor,
	bool? resizeToAvoidBottomInset,
	bool primary = true,
	DragStartBehavior drawerDragStartBehavior = DragStartBehavior.start,
	bool extendBody = false,
	bool extendBodyBehindAppBar = false,
	Color? drawerScrimColor,
	double? drawerEdgeDragWidth,
	bool drawerEnableOpenDragGesture = true,
	bool endDrawerEnableOpenDragGesture = true,
	String? restorationId
})

属性
- appBar → PreferredSizeWidget?：顶部应用程序栏。由一个标题栏和其它可能的组件组成。
- body → Widget?：界面主要内容。
- bottomNavigationBar → Widget?：底部导航栏。
- drawer → Widget?：从左侧滑出的抽屉组件。
- floatingActionButton → Widget?：浮动操作按钮。Z轴它位于整个界面之上。
- floatingActionButtonLocation → FloatingActionButtonLocation?：浮动操作按钮的位置。默认在界面右下角。

ScaffoldMessenger —— 脚手架信使

静态方法
- of(BuildContext context) → ScaffoldMessengerState

ScaffoldMessengerState —— 脚手架信使状态

方法
- showSnackBar(SnackBar snackBar, {AnimationStyle? snackBarAnimationStyle}) → ScaffoldFeatureController<SnackBar, SnackBarClosedReason>

SimpleDialog —— 简单对话框

继承
Object > DiagnosticableTree > Widget > StatelessWidget > SimpleDialog

构造函数

SimpleDialog({
	Key? key,
	Widget? title,
	EdgeInsetsGeometry titlePadding = const EdgeInsets.fromLTRB(24.0, 24.0, 24.0, 0.0),
	TextStyle? titleTextStyle,
	List<Widget>? children,
	EdgeInsetsGeometry contentPadding = const EdgeInsets.fromLTRB(0.0, 12.0, 0.0, 16.0),
	Color? backgroundColor,
	double? elevation,
	Color? shadowColor,
	Color? surfaceTintColor,
	String? semanticLabel,
	EdgeInsets? insetPadding,
	Clip? clipBehavior,
	ShapeBorder? shape,
	AlignmentGeometry? alignment
})

属性
- children → List<Widget>?：子组件列表。总是纵向排列。
- title → Widget?：标题。

SimpleDialogOption —— 简单对话框的选项

继承
Object > DiagnosticableTree > Widget > StatelessWidget > SimpleDialogOption

构造函数

SimpleDialogOption({
	Key? key,
	VoidCallback? onPressed,
	EdgeInsets? padding,
	Widget? child
})

Slider —— 滑块

继承
Object > DiagnosticableTree > Widget > StatefulWidget > Slider

构造函数

Slider({
	Key? key,
	required double value,
	double? secondaryTrackValue,
	required ValueChanged<double>? onChanged,
	ValueChanged<double>? onChangeStart,
	ValueChanged<double>? onChangeEnd,
	double min = 0.0,
	double max = 1.0,
	int? divisions,
	String? label,
	Color? activeColor,
	Color? inactiveColor,
	Color? secondaryActiveColor,
	Color? thumbColor,
	MaterialStateProperty<Color?>? overlayColor,
	MouseCursor? mouseCursor,
	SemanticFormatterCallback? semanticFormatterCallback,
	FocusNode? focusNode,
	bool autofocus = false,
	SliderInteraction? allowedInteraction
})

属性
- activeColor → Color?：滑过部分的颜色。
- inactiveColor → Color?：未滑过部分的颜色。
- max → double：最大位置值。
- min → double：最小位置值。
- onChanged → ValueChanged<double>?：滑动过程中的回调。Slider不维护任何状态，需要在此方法中重绘滑块。
- onChangeEnd → ValueChanged<double>?：滑动结束的回调。
- onChangeStart → ValueChanged<double>?：滑动开始的回调。
- value → double：当前位置值。

SnackBar —— 底部提示栏

继承
Object > DiagnosticableTree > Widget > StatefulWidget > SnackBar

构造函数

SnackBar({
	Key? key,
	required Widget content,
	Color? backgroundColor,
	double? elevation,
	EdgeInsetsGeometry? margin,
	EdgeInsetsGeometry? padding,
	double? width,
	ShapeBorder? shape,
	HitTestBehavior? hitTestBehavior,
	SnackBarBehavior? behavior,
	SnackBarAction? action,
	double? actionOverflowThreshold,
	bool? showCloseIcon,
	Color? closeIconColor,
	Duration duration = _snackBarDisplayDuration,
	Animation<double>? animation,
	VoidCallback? onVisible,
	DismissDirection? dismissDirection,
	Clip clipBehavior = Clip.hardEdge
})

*属性
* action → SnackBarAction?：用来触发一个快捷操作。
* backgroundColor → Color?：背景色。默认为深灰色。
* content → Widget：内容。
* duration → Duration：显示的持续时长。

Switch —— 开关

继承
Object > DiagnosticableTree > Widget > StatelessWidget > Switch

构造函数

Switch({
	Key? key,
	required bool value,
	required ValueChanged\<bool>? onChanged,
	Color? activeColor,
	Color? activeTrackColor,
	Color? inactiveThumbColor,
	Color? inactiveTrackColor,
	ImageProvider<Object>? activeThumbImage,
	ImageErrorListener? onActiveThumbImageError,
	ImageProvider<Object>? inactiveThumbImage,
	ImageErrorListener? onInactiveThumbImageError,
	MaterialStateProperty<Color?>? thumbColor,
	MaterialStateProperty<Color?>? trackColor,
	MaterialStateProperty<Color?>? trackOutlineColor,
	MaterialStateProperty<double?>? trackOutlineWidth,
	MaterialStateProperty<Icon?>? thumbIcon,
	MaterialTapTargetSize? materialTapTargetSize,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	MouseCursor? mouseCursor,
	Color? focusColor,
	Color? hoverColor,
	MaterialStateProperty<Color?>? overlayColor,
	double? splashRadius,
	FocusNode? focusNode,
	ValueChanged<bool>? onFocusChange,
	bool autofocus = false
})

Tab —— 选项卡

继承
Object > DiagnosticableTree > Widget > StatelessWidget > Tab

构造函数

Tab({
	Key? key,
	String? text,
	Widget? icon,
	EdgeInsetsGeometry? iconMargin,
	double? height,
	Widget? child
})

TabBar —— 选项卡栏

继承
Object > DiagnosticableTree > Widget > StatefulWidget > TabBar

构造函数

TabBar({
	Key? key,
	required List<Widget> tabs,
	TabController? controller,
	bool isScrollable = false,
	EdgeInsetsGeometry? padding,
	Color? indicatorColor,
	bool automaticIndicatorColorAdjustment = true,
	double indicatorWeight = 2.0,
	EdgeInsetsGeometry indicatorPadding = EdgeInsets.zero,
	Decoration? indicator,
	TabBarIndicatorSize? indicatorSize,
	Color? dividerColor,
	double? dividerHeight,
	Color? labelColor,
	TextStyle? labelStyle,
	EdgeInsetsGeometry? labelPadding,
	Color? unselectedLabelColor,
	TextStyle? unselectedLabelStyle,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	MaterialStateProperty<Color?>? overlayColor,
	MouseCursor? mouseCursor,
	bool? enableFeedback,
	ValueChanged<int>? onTap,
	ScrollPhysics? physics,
	InteractiveInkFeatureFactory? splashFactory,
	BorderRadius? splashBorderRadius,
	TabAlignment? tabAlignment,
	TextScaler? textScaler
})

属性
- controller → TabController?：选项卡控制器。
- indicatorColor → Color?：选项卡下方的选中指示器颜色。
- indicatorSize → TabBarIndicatorSize?：选项卡的宽度。
- indicatorWeight → double：选项卡下方的选中指示器高度。
- tabs → List<Widget>：选项卡列表。

TabBarView —— 选项卡栏页面内容视图

继承
Object > DiagnosticableTree > Widget > StatefulWidget > TabBarView

构造函数

TabBarView({
	Key? key,
	required List<Widget> children,
	TabController? controller,
	ScrollPhysics? physics,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	double viewportFraction = 1.0,
	Clip clipBehavior = Clip.hardEdge
})

TabController —— 水平选项卡控制器

继承
Object > ChangeNotifier > TabController

构造函数

TabController({
	int initialIndex = 0,
	Duration? animationDuration,
	required int length,
	required TickerProvider vsync
})

方法
- dispose() → void

TextButton —— 文本按钮

继承
Object > DiagnosticableTree > Widget > StatefulWidget > ButtonStyleButton > TextButton

构造函数

TextButton({
	Key? key,
	required VoidCallback? onPressed,
	VoidCallback? onLongPress,
	ValueChanged<bool>? onHover,
	ValueChanged<bool>? onFocusChange,
	ButtonStyle? style,
	FocusNode? focusNode,
	bool autofocus = false,
	Clip? clipBehavior,
	MaterialStatesController? statesController,
	bool? isSemanticButton = true,
	required Widget child,
	IconAlignment iconAlignment = IconAlignment.start
})

TextField —— 文本框字段

继承
Object > DiagnosticableTree > Widget > StatefulWidget > TextField

构造函数

TextField({
	Key? key,
	Object groupId = EditableText,
	TextEditingController? controller,
	FocusNode? focusNode,
	UndoHistoryController? undoController,
	InputDecoration? decoration = const InputDecoration(),
	TextInputType? keyboardType,
	TextInputAction? textInputAction,
	TextCapitalization textCapitalization = TextCapitalization.none,
	TextStyle? style,
	StrutStyle? strutStyle,
	TextAlign textAlign = TextAlign.start,
	TextAlignVertical? textAlignVertical,
	TextDirection? textDirection,
	bool readOnly = false,
	@Deprecated(
		'Use `contextMenuBuilder` instead. '
		'This feature was deprecated after v3.3.0-0.5.pre.'
	)
	ToolbarOptions? toolbarOptions,
	bool? showCursor,
	bool autofocus = false,
	MaterialStatesController? statesController,
	String obscuringCharacter = '•',
	bool obscureText = false,
	bool autocorrect = true,
	SmartDashesType? smartDashesType,
	SmartQuotesType? smartQuotesType,
	bool enableSuggestions = true,
	int? maxLines = 1,
	int? minLines,
	bool expands = false,
	int? maxLength,
	MaxLengthEnforcement? maxLengthEnforcement,
	ValueChanged<String>? onChanged,
	VoidCallback? onEditingComplete,
	ValueChanged<String>? onSubmitted,
	AppPrivateCommandCallback? onAppPrivateCommand,
	List<TextInputFormatter>? inputFormatters,
	bool? enabled,
	bool? ignorePointers,
	double cursorWidth = 2.0,
	double? cursorHeight,
	Radius? cursorRadius,
	bool? cursorOpacityAnimates,
	Color? cursorColor,
	Color? cursorErrorColor,
	BoxHeightStyle selectionHeightStyle = ui.BoxHeightStyle.tight,
	BoxWidthStyle selectionWidthStyle = ui.BoxWidthStyle.tight,
	Brightness? keyboardAppearance,
	EdgeInsets scrollPadding = const EdgeInsets.all(20.0),
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	bool? enableInteractiveSelection,
	TextSelectionControls? selectionControls,
	GestureTapCallback? onTap,
	bool onTapAlwaysCalled = false,
	TapRegionCallback? onTapOutside,
	MouseCursor? mouseCursor,
	InputCounterWidgetBuilder? buildCounter,
	ScrollController? scrollController,
	ScrollPhysics? scrollPhysics,
	Iterable<String>? autofillHints = const <String>[],
	ContentInsertionConfiguration? contentInsertionConfiguration,
	Clip clipBehavior = Clip.hardEdge,
	String? restorationId,
	bool scribbleEnabled = true,
	bool enableIMEPersonalizedLearning = true,
	EditableTextContextMenuBuilder? contextMenuBuilder = _defaultContextMenuBuilder,
	bool canRequestFocus = true,
	SpellCheckConfiguration? spellCheckConfiguration,
	TextMagnifierConfiguration? magnifierConfiguration
})

属性
- autofocus → bool：是否自动获取焦点。
- controller → TextEditingController?：文本编辑控制器。
- decoration → InputDecoration?：输入装饰。
- maxLines → int?：最大行数。默认为1。
- maxLength → int?：文本最大长度。如指定，则当前长度和最大长度会显示在文本框右下角。
- maxLengthEnforcement → MaxLengthEnforcement?
- keyboardType → TextInputType：弹出软键盘的类型。
- obscureText → bool：是否隐藏文本明文。
- onChanged → ValueChanged<String>?：文本内容变更时的回调。
- onEditingComplete → VoidCallback?：文本编辑完成时的回调。
- onSubmitted → ValueChanged<String>?：文本提交时的回调。
- textInputAction → TextInputAction?：文本输入操作。

TextFormField —— 表单文本框字段

继承
Object > DiagnosticableTree > Widget > StatefulWidget > FormField<String> > TextFormField

构造函数

TextFormField({
	Key? key,
	Object groupId = EditableText,
	TextEditingController? controller,
	String? initialValue,
	FocusNode? focusNode,
	String? forceErrorText,
	InputDecoration? decoration = const InputDecoration(),
	TextInputType? keyboardType,
	TextCapitalization textCapitalization = TextCapitalization.none,
	TextInputAction? textInputAction,
	TextStyle? style,
	StrutStyle? strutStyle,
	TextDirection? textDirection,
	TextAlign textAlign = TextAlign.start,
	TextAlignVertical? textAlignVertical,
	bool autofocus = false,
	bool readOnly = false,
	@Deprecated(
		'Use `contextMenuBuilder` instead. '
		'This feature was deprecated after v3.3.0-0.5.pre.'
	)
	ToolbarOptions? toolbarOptions,
	bool? showCursor,
	String obscuringCharacter = '•',
	bool obscureText = false,
	bool autocorrect = true,
	SmartDashesType? smartDashesType,
	SmartQuotesType? smartQuotesType,
	bool enableSuggestions = true,
	MaxLengthEnforcement? maxLengthEnforcement,
	int? maxLines = 1,
	int? minLines,
	bool expands = false,
	int? maxLength,
	ValueChanged<String>? onChanged,
	GestureTapCallback? onTap,
	bool onTapAlwaysCalled = false,
	TapRegionCallback? onTapOutside,
	VoidCallback? onEditingComplete,
	ValueChanged<String>? onFieldSubmitted,
	FormFieldSetter<String>? onSaved,
	FormFieldValidator<String>? validator,
	List<TextInputFormatter>? inputFormatters,
	bool? enabled,
	bool? ignorePointers,
	double cursorWidth = 2.0,
	double? cursorHeight,
	Radius? cursorRadius,
	Color? cursorColor,
	Color? cursorErrorColor,
	Brightness? keyboardAppearance,
	EdgeInsets scrollPadding = const EdgeInsets.all(20.0),
	bool? enableInteractiveSelection,
	TextSelectionControls? selectionControls,
	InputCounterWidgetBuilder? buildCounter,
	ScrollPhysics? scrollPhysics,
	Iterable<String>? autofillHints,
	AutovalidateMode? autovalidateMode,
	ScrollController? scrollController,
	String? restorationId,
	bool enableIMEPersonalizedLearning = true,
	MouseCursor? mouseCursor,
	EditableTextContextMenuBuilder? contextMenuBuilder = _defaultContextMenuBuilder,
	SpellCheckConfiguration? spellCheckConfiguration,
	TextMagnifierConfiguration? magnifierConfiguration,
	UndoHistoryController? undoController,
	AppPrivateCommandCallback? onAppPrivateCommand,
	bool? cursorOpacityAnimates,
	BoxHeightStyle selectionHeightStyle = ui.BoxHeightStyle.tight,
	BoxWidthStyle selectionWidthStyle = ui.BoxWidthStyle.tight,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	ContentInsertionConfiguration? contentInsertionConfiguration,
	MaterialStatesController? statesController,
	Clip clipBehavior = Clip.hardEdge,
	bool scribbleEnabled = true,
	bool canRequestFocus = true
})

属性
- onSaved → FormFieldSetter<String>?：文本保存时的回调。
- validator → FormFieldValidator<String>?：文本内容校验器。

Theme —— 主题

继承
Object > DiagnosticableTree > Widget > StatelessWidget > Theme

构造函数

Theme({
	Key? key,
	required ThemeData data,
	required Widget child
})

属性
- child → Widget：子组件。
- data → ThemeData：主题数据。
静态方法
- of(BuildContext context) → ThemeData：获取上下文的主题数据。

ThemeData —— 主题数据

构造函数

ThemeData({
	Iterable<Adaptation<Object>>? adaptations,
	bool? applyElevationOverlayColor,
	NoDefaultCupertinoThemeData? cupertinoOverrideTheme,
	Iterable<ThemeExtension>? extensions,
	InputDecorationTheme? inputDecorationTheme,
	MaterialTapTargetSize? materialTapTargetSize,
	PageTransitionsTheme? pageTransitionsTheme,
	TargetPlatform? platform,
	ScrollbarThemeData? scrollbarTheme,
	InteractiveInkFeatureFactory? splashFactory,
	bool? useMaterial3,
	VisualDensity? visualDensity,
	ColorScheme? colorScheme,
	Brightness? brightness,
	Color? colorSchemeSeed,
	Color? canvasColor,
	Color? cardColor,
	Color? dialogBackgroundColor,
	Color? disabledColor,
	Color? dividerColor,
	Color? focusColor,
	Color? highlightColor,
	Color? hintColor,
	Color? hoverColor,
	Color? indicatorColor,
	Color? primaryColor,
	Color? primaryColorDark,
	Color? primaryColorLight,
	MaterialColor? primarySwatch,
	Color? scaffoldBackgroundColor,
	Color? secondaryHeaderColor,
	Color? shadowColor,
	Color? splashColor,
	Color? unselectedWidgetColor,
	String? fontFamily,
	List<String>? fontFamilyFallback,
	String? package,
	IconThemeData? iconTheme,
	IconThemeData? primaryIconTheme,
	TextTheme? primaryTextTheme,
	TextTheme? textTheme,
	Typography? typography,
	ActionIconThemeData? actionIconTheme,
	AppBarTheme? appBarTheme,
	BadgeThemeData? badgeTheme,
	MaterialBannerThemeData? bannerTheme,
	BottomAppBarTheme? bottomAppBarTheme,
	BottomNavigationBarThemeData? bottomNavigationBarTheme,
	BottomSheetThemeData? bottomSheetTheme,
	ButtonThemeData? buttonTheme,
	CardTheme? cardTheme,
	CheckboxThemeData? checkboxTheme,
	ChipThemeData? chipTheme,
	DataTableThemeData? dataTableTheme,
	DatePickerThemeData? datePickerTheme,
	DialogTheme? dialogTheme,
	DividerThemeData? dividerTheme,
	DrawerThemeData? drawerTheme,
	DropdownMenuThemeData? dropdownMenuTheme,
	ElevatedButtonThemeData? elevatedButtonTheme,
	ExpansionTileThemeData? expansionTileTheme,
	FilledButtonThemeData? filledButtonTheme,
	FloatingActionButtonThemeData? floatingActionButtonTheme,
	IconButtonThemeData? iconButtonTheme,
	ListTileThemeData? listTileTheme,
	MenuBarThemeData? menuBarTheme,
	MenuButtonThemeData? menuButtonTheme,
	MenuThemeData? menuTheme,
	NavigationBarThemeData? navigationBarTheme,
	NavigationDrawerThemeData? navigationDrawerTheme,
	NavigationRailThemeData? navigationRailTheme,
	OutlinedButtonThemeData? outlinedButtonTheme,
	PopupMenuThemeData? popupMenuTheme,
	ProgressIndicatorThemeData? progressIndicatorTheme,
	RadioThemeData? radioTheme,
	SearchBarThemeData? searchBarTheme,
	SearchViewThemeData? searchViewTheme,
	SegmentedButtonThemeData? segmentedButtonTheme,
	SliderThemeData? sliderTheme,
	SnackBarThemeData? snackBarTheme,
	SwitchThemeData? switchTheme,
	TabBarTheme? tabBarTheme,
	TextButtonThemeData? textButtonTheme,
	TextSelectionThemeData? textSelectionTheme,
	TimePickerThemeData? timePickerTheme,
	ToggleButtonsThemeData? toggleButtonsTheme,
	TooltipThemeData? tooltipTheme,
	@Deprecated(
		'Use OverflowBar instead. '
		'This feature was deprecated after v3.21.0-10.0.pre.'
	)
	ButtonBarThemeData? buttonBarTheme
})

fontFamily：字体族。

属性
- primaryColor → Color：主颜色。
方法
- copyWith({Iterable<Adaptation<Object>>? adaptations, bool? applyElevationOverlayColor, NoDefaultCupertinoThemeData? cupertinoOverrideTheme, Iterable<ThemeExtension>? extensions, InputDecorationTheme? inputDecorationTheme, MaterialTapTargetSize? materialTapTargetSize, PageTransitionsTheme? pageTransitionsTheme, TargetPlatform? platform, ScrollbarThemeData? scrollbarTheme, InteractiveInkFeatureFactory? splashFactory, VisualDensity? visualDensity, ColorScheme? colorScheme, Brightness? brightness, Color? canvasColor, Color? cardColor, Color? dialogBackgroundColor, Color? disabledColor, Color? dividerColor, Color? focusColor, Color? highlightColor, Color? hintColor, Color? hoverColor, Color? indicatorColor, Color? primaryColor, Color? primaryColorDark, Color? primaryColorLight, Color? scaffoldBackgroundColor, Color? secondaryHeaderColor, Color? shadowColor, Color? splashColor, Color? unselectedWidgetColor, IconThemeData? iconTheme, IconThemeData? primaryIconTheme, TextTheme? primaryTextTheme, TextTheme? textTheme, Typography? typography, ActionIconThemeData? actionIconTheme, AppBarTheme? appBarTheme, BadgeThemeData? badgeTheme, MaterialBannerThemeData? bannerTheme, BottomAppBarTheme? bottomAppBarTheme, BottomNavigationBarThemeData? bottomNavigationBarTheme, BottomSheetThemeData? bottomSheetTheme, ButtonThemeData? buttonTheme, CardTheme? cardTheme, CheckboxThemeData? checkboxTheme, ChipThemeData? chipTheme, DataTableThemeData? dataTableTheme, DatePickerThemeData? datePickerTheme, DialogTheme? dialogTheme, DividerThemeData? dividerTheme, DrawerThemeData? drawerTheme, DropdownMenuThemeData? dropdownMenuTheme, ElevatedButtonThemeData? elevatedButtonTheme, ExpansionTileThemeData? expansionTileTheme, FilledButtonThemeData? filledButtonTheme, FloatingActionButtonThemeData? floatingActionButtonTheme, IconButtonThemeData? iconButtonTheme, ListTileThemeData? listTileTheme, MenuBarThemeData? menuBarTheme, MenuButtonThemeData? menuButtonTheme, MenuThemeData? menuTheme, NavigationBarThemeData? navigationBarTheme, NavigationDrawerThemeData? navigationDrawerTheme, NavigationRailThemeData? navigationRailTheme, OutlinedButtonThemeData? outlinedButtonTheme, PopupMenuThemeData? popupMenuTheme, ProgressIndicatorThemeData? progressIndicatorTheme, RadioThemeData? radioTheme, SearchBarThemeData? searchBarTheme, SearchViewThemeData? searchViewTheme, SegmentedButtonThemeData? segmentedButtonTheme, SliderThemeData? sliderTheme, SnackBarThemeData? snackBarTheme, SwitchThemeData? switchTheme, TabBarTheme? tabBarTheme, TextButtonThemeData? textButtonTheme, TextSelectionThemeData? textSelectionTheme, TimePickerThemeData? timePickerTheme, ToggleButtonsThemeData? toggleButtonsTheme, TooltipThemeData? tooltipTheme, bool? useMaterial3, ButtonBarThemeData? buttonBarTheme}) → ThemeData：复制并自定义部分属性。

TimeOfDay —— 一天中的时间

构造函数

TimeOfDay({required int hour, required int minute})

当前时间：

TimeOfDay.now()

在长按时进行提示。

继承
Object > DiagnosticableTree > Widget > StatefulWidget > Tooltip

构造函数

Tooltip({
	Key? key,
	String? message,
	InlineSpan? richMessage,
	double? height,
	EdgeInsetsGeometry? padding,
	EdgeInsetsGeometry? margin,
	double? verticalOffset,
	bool? preferBelow,
	bool? excludeFromSemantics,
	Decoration? decoration,
	TextStyle? textStyle,
	TextAlign? textAlign,
	Duration? waitDuration,
	Duration? showDuration,
	Duration? exitDuration,
	bool enableTapToDismiss = true,
	TooltipTriggerMode? triggerMode,
	bool? enableFeedback,
	TooltipTriggeredCallback? onTriggered,
	Widget? child
})

属性
- child → Widget?

UnderlineTabIndicator —— 下划线

为子组件添加下划线。

继承
Object > Decoration > UnderlineTabIndicator

构造函数

UnderlineTabIndicator({
	BorderRadius? borderRadius,
	BorderSide borderSide = const BorderSide(width: 2.0, color: Colors.white),
	EdgeInsetsGeometry insets = EdgeInsets.zero
})

UserAccountsDrawerHeader —— 展示用户账号信息的抽屉头

继承
Object > DiagnosticableTree > Widget > StatefulWidget > UserAccountsDrawerHeader

构造函数

UserAccountsDrawerHeader({
	Key? key,
	Decoration? decoration,
	EdgeInsetsGeometry? margin = const EdgeInsets.only(bottom: 8.0),
	Widget? currentAccountPicture,
	List<Widget>? otherAccountsPictures,
	Size currentAccountPictureSize = const Size.square(72.0),
	Size otherAccountsPicturesSize = const Size.square(40.0),
	required Widget? accountName,
	required Widget? accountEmail,
	VoidCallback? onDetailsPressed,
	Color arrowColor = Colors.white
})

枚举

TabBarIndicatorSize —— 选项卡栏指示器大小

值
- label → const TabBarIndicatorSize：每个选项卡调整为适合实际内容的宽度。
- tab → const TabBarIndicatorSize：所有选项卡等宽，均分空间。

函数

showDatePicker —— 展示日期选择器

调用系统的组件。

Future<DateTime?> showDatePicker({
	required BuildContext context,
	DateTime? initialDate,
	required DateTime firstDate,
	required DateTime lastDate,
	DateTime? currentDate,
	DatePickerEntryMode initialEntryMode = DatePickerEntryMode.calendar,
	SelectableDayPredicate? selectableDayPredicate,
	String? helpText,
	String? cancelText,
	String? confirmText,
	Locale? locale,
	bool barrierDismissible = true,
	Color? barrierColor,
	String? barrierLabel,
	bool useRootNavigator = true,
	RouteSettings? routeSettings,
	TextDirection? textDirection,
	TransitionBuilder? builder,
	DatePickerMode initialDatePickerMode = DatePickerMode.day,
	String? errorFormatText,
	String? errorInvalidText,
	String? fieldHintText,
	String? fieldLabelText,
	TextInputType? keyboardType,
	Offset? anchorPoint,
	ValueChanged<DatePickerEntryMode>? onDatePickerModeChange,
	Icon? switchToInputEntryModeIcon,
	Icon? switchToCalendarEntryModeIcon,
})

context：构建上下文。
firstDate：可选择的开始日期。
initialDate：初始显示的日期。
lastDate：可选中的结束日期。

showDialog —— 展示对话框

Future<T?> showDialog<T>({
	required BuildContext context,
	required WidgetBuilder builder,
	bool barrierDismissible = true,
	Color? barrierColor,
	String? barrierLabel,
	bool useSafeArea = true,
	bool useRootNavigator = true,
	RouteSettings? routeSettings,
	Offset? anchorPoint,
	TraversalEdgeBehavior? traversalEdgeBehavior,
})

showTimePicker —— 展示时间选择器

调用系统的组件。

Future<TimeOfDay?> showTimePicker({
	required BuildContext context,
	required TimeOfDay initialTime,
	TransitionBuilder? builder,
	bool barrierDismissible = true,
	Color? barrierColor,
	String? barrierLabel,
	bool useRootNavigator = true,
	TimePickerEntryMode initialEntryMode = TimePickerEntryMode.dial,
	String? cancelText,
	String? confirmText,
	String? helpText,
	String? errorInvalidText,
	String? hourLabelText,
	String? minuteLabelText,
	RouteSettings? routeSettings,
	EntryModeChangeCallback? onEntryModeChanged,
	Offset? anchorPoint,
	Orientation? orientation,
})

context：构建上下文。
initialTime：初始显示的时间。

import 'package:flutter/painting.dart';

类

Alignment —— 对齐

继承
Object > AlignmentGeometry > Alignment
构造函数
```
Alignment(double x, double y)
```
常量
- bottomCenter → const Alignment
- bottomLeft → const Alignment
- bottomRight → const Alignment
- center → const Alignment
- centerLeft → const Alignment
- centerRight → const Alignment
- topCenter → const Alignment
- topLeft → const Alignment
- topRight → const Alignment

AlignmentDirectional —— 对齐方向

继承
Object > AlignmentGeometry > AlignmentDirectional

构造函数

AlignmentDirectional(double start, double y)

常量
- bottomCenter → const AlignmentDirectional
- bottomEnd → const AlignmentDirectional
- bottomStart → const AlignmentDirectional
- center → const AlignmentDirectional
- centerEnd → const AlignmentDirectional
- centerStart → const AlignmentDirectional
- topCenter → const AlignmentDirectional
- topEnd → const AlignmentDirectional
- topStart → const AlignmentDirectional

AssetImage —— 资源图片

继承
Object > ImageProvider<AssetBundleImageKey> > AssetBundleImageProvider > AssetImage

构造函数

AssetImage(
	String assetName,
	{
	AssetBundle? bundle,
	String? package
	}
)

Axis —— 坐标轴

继承
Object > Enum > Axis
值
- horizontal → const Axis：水平坐标轴。
- vertical → const Axis：垂直坐标轴。

BorderRadius —— 边框圆角半径

继承
Object > BorderRadiusGeometry > BorderRadius
构造函数
```
BorderRadius.circular(double radius)
```

BoxDecoration —— 盒装饰

继承
Object > Decoration > BoxDecoration

构造函数

BoxDecoration({
	Color? color,
	DecorationImage? image,
	BoxBorder? border,
	BorderRadiusGeometry? borderRadius,
	List<BoxShadow>? boxShadow,
	Gradient? gradient,
	BlendMode? backgroundBlendMode,
	BoxShape shape = BoxShape.rectangle
})

属性
- backgroundBlendMode → BlendMode?：背景混合模式。
- border → BoxBorder?：边框。
- borderRadius → BorderRadiusGeometry?：边框圆角半径。
- boxShadow → List<BoxShadow>?：阴影。
- color → Color?：颜色。
- gradient → Gradient?：渐变。
- image → DecorationImage?：图片。
- shape → BoxShape：形状。

EdgeInsets —— 边缘镶嵌

继承
Object > EdgeInsetsGeometry > EdgeInsets

构造函数

所有边距使用相同的值：

EdgeInsets.all(double value)

分布指定四个方向的边距：

EdgeInsets.fromLTRB(double left, double top, double right, double bottom)

可只指定某些方向的边距：

EdgeInsets.only({double left = 0.0, double top = 0.0, double right = 0.0, double bottom = 0.0})

可只指定某些对称方向的边距：

EdgeInsets.symmetric({double vertical = 0.0, double horizontal = 0.0})

常量
- zero → const EdgeInsets

FlutterLogoDecoration —— Flutter的logo装饰

继承
Object > Decoration > FlutterLogoDecoration

构造函数

FlutterLogoDecoration({
	Color textColor = const Color(0xFF757575),
	FlutterLogoStyle style = FlutterLogoStyle.markOnly,
	EdgeInsets margin = EdgeInsets.zero
})

LinearGradient —— 线性渐变

继承
Object > Gradient > LinearGradient

构造函数

LinearGradient({
	AlignmentGeometry begin = Alignment.centerLeft,
	AlignmentGeometry end = Alignment.centerRight,
	required List<Color> colors,
	List<double>? stops,
	TileMode tileMode = TileMode.clamp,
	GradientTransform? transform
})

NetworkImage —— 网络图片

继承
Object > ImageProvider<NetworkImage> > NetworkImage

构造函数

NetworkImage(
	String url,
	{
	double scale,
	Map<String, String>? headers
	}
)

ShapeDecoration —— 形状装饰

继承
Object > Decoration > ShapeDecoration

构造函数

ShapeDecoration({
	Color? color,
	DecorationImage? image,
	Gradient? gradient,
	List<BoxShadow>? shadows,
	required ShapeBorder shape
})

TextSpan —— 文本片段

继承
Object > DiagnosticableTree > InlineSpan > TextSpan

构造函数

TextSpan({
	String? text,
	List<InlineSpan>? children,
	TextStyle? style,
	GestureRecognizer? recognizer,
	MouseCursor? mouseCursor,
	PointerEnterEventListener? onEnter,
	PointerExitEventListener? onExit,
	String? semanticsLabel,
	Locale? locale,
	bool? spellOut
})

属性
- recognizer → GestureRecognizer?：触摸事件手势识别器。

TextStyle —— 文本样式

构造函数

TextStyle({
	bool inherit = true,
	Color? color,
	Color? backgroundColor,
	double? fontSize,
	FontWeight? fontWeight,
	FontStyle? fontStyle,
	double? letterSpacing,
	double? wordSpacing,
	TextBaseline? textBaseline,
	double? height,
	TextLeadingDistribution? leadingDistribution,
	Locale? locale,
	Paint? foreground,
	Paint? background,
	List<Shadow>? shadows,
	List<FontFeature>? fontFeatures,
	List<FontVariation>? fontVariations,
	TextDecoration? decoration,
	Color? decorationColor,
	TextDecorationStyle? decorationStyle,
	double? decorationThickness,
	String? debugLabel,
	String? fontFamily,
	List<String>? fontFamilyFallback,
	String? package,
	TextOverflow? overflow
})

package：包名。字体在某个包中但该字体未在pubspec.yaml中声明时使用。

属性
- background → Paint?：背景色。
- color → Color?：文本颜色。
- fontFamily → String?：字体族。
- fontSize → double?：字体大小。
- decoration → TextDecoration?：背景装饰。

枚举

ImageRepeat —— 图片重复方式

值
- repeat → const ImageRepeat
- repeatX → const ImageRepeat
- repeatY → const ImageRepeat
- noRepeat → const ImageRepeat

TextOverflow —— 文本溢出方式

值
- clip → const TextOverflow
- fade → const TextOverflow
- ellipsis → const TextOverflow：溢出的文本以“...”方式表示。
- visible → const TextOverflow

VerticalDirection —— 垂直方向

值
- up → const VerticalDirection：从下到上。
- down → const VerticalDirection：从上到下。

import 'package:path/path.dart';

函数

join(String part1, [String? part2, String? part3, String? part4, String? part5, String? part6, String? part7, String? part8, String? part9, String? part10, String? part11, String? part12, String? part13, String? part14, String? part15, String? part16]) → String：路径拼接。

import 'package:flutter/rendering.dart';

类

BoxConstraints —— 盒约束

继承
Object > Constraints > BoxConstraints

构造函数

BoxConstraints({
	double minWidth = 0.0,
	double maxWidth = double.infinity,
	double minHeight = 0.0,
	double maxHeight = double.infinity
})

属性
- maxHeight → double：最大高度。
- maxWidth → double：最大宽度。
- minHeight → double：最小高度。
- minWidth → double：最小宽度。

SliverGridDelegateWithFixedCrossAxisCount —— Sliver家族的固定交叉轴方向元素数量的网格代理

滚动方向为主轴方向。

继承
Object > SliverGridDelegate > SliverGridDelegateWithFixedCrossAxisCount

构造函数

SliverGridDelegateWithFixedCrossAxisCount({
	required int crossAxisCount,
	double mainAxisSpacing = 0.0,
	double crossAxisSpacing = 0.0,
	double childAspectRatio = 1.0,
	double? mainAxisExtent
})

属性
- childAspectRatio → double：子组件在交叉轴方向和主轴方向上的尺寸比例。
- crossAxisCount → int：交叉轴方向元素数量。
- crossAxisSpacing → double：交叉轴方向子组件间距。
- mainAxisExtent → double?：主轴方向子组件间距。

SliverGridDelegateWithMaxCrossAxisExtent —— Sliver家族的指定交叉轴方向元素最大尺寸的网格代理

滚动方向为主轴方向。

继承
Object > SliverGridDelegate > SliverGridDelegateWithMaxCrossAxisExtent

构造函数

SliverGridDelegateWithMaxCrossAxisExtent({
	required double maxCrossAxisExtent,
	double mainAxisSpacing = 0.0,
	double crossAxisSpacing = 0.0,
	double childAspectRatio = 1.0,
	double? mainAxisExtent
})

属性
- maxCrossAxisExtent → double：元素在交叉轴方向上的最大尺寸。因为所有子组件是平均分配交叉轴的空间，实际值会在此值的一个范围附近。

枚举

CrossAxisAlignment —— 交叉轴对齐方式

值
- start → const CrossAxisAlignment
- end → const CrossAxisAlignment
- center → const CrossAxisAlignment
- stretch → const CrossAxisAlignment
- baseline → const CrossAxisAlignment

DecorationPosition —— 装饰位置

值
- background → const DecorationPosition：子组件后。
- foreground → const DecorationPosition：子组件前。

HitTestBehavior —— 点击行为

值
- deferToChild → const HitTestBehavior：事件会逐个在每一层组件上响应。
- opaque → const HitTestBehavior：强制视作不透明组件，使组件全部空间都可响应事件，阻断其背后组件的响应。（默认情况下，组件的透明部分会被穿透，不响应事件。）
- translucent → const HitTestBehavior：强制视作半透明组件，会被穿透，背后组件亦可响应事件。

MainAxisAlignment —— 主轴对齐方式

值
- start → const MainAxisAlignment
- end → const MainAxisAlignment
- center → const MainAxisAlignment
- spaceBetween → const MainAxisAlignment
- spaceAround → const MainAxisAlignment
- spaceEvenly → const MainAxisAlignment

MainAxisSize —— 主轴所占空间大小

值
- min → const MainAxisSize：尽可能少占用空间，即可以容纳所有子组件的最小尺寸。
- max → const MainAxisSize：尽可能多占用空间，即使子组件没有占满。

StackFit —— 栈布局/堆叠布局的适应方式

值
- loose → const StackFit：使用子组件的大小。
- expand → const StackFit：填充整个Stack。
- passthrough → const StackFit

属性

debugPaintBaselinesEnabled —— 是否显示绘图的基线

对于具有基线的组件，文字基线以亮绿色显示，表意基线以橙色显示。

bool debugPaintBaselinesEnabled

debugPaintPointersEnabled —— 是否显示绘图的点击位

被点击的组件以深青色高亮显示。

bool debugPaintPointersEnabled

debugPaintSizeEnabled —— 是否显示绘图的大小

边界以青色边框显示，对齐方式以黄色箭头显示。

bool debugPaintSizeEnabled

函数

debugDumpLayerTree —— 转储层级关系

void debugDumpLayerTree()

debugDumpRenderTree —— 转储渲染层

void debugDumpRenderTree()

debugDumpSemanticsTree —— 转储语义调试

void debugDumpSemanticsTree([ DebugSemanticsDumpOrder childOrder = DebugSemanticsDumpOrder.traversalOrder ])

import 'package:flutter/scheduler.dart';

属性

debugPrintBeginFrameBanner —— 打印帧开始

debugPrintBeginFrameBanner ↔ bool

debugPrintEndFrameBanner —— 打印帧结束

debugPrintEndFrameBanner ↔ bool

timeDilation —— 动画时间放慢倍数

应只在程序启动后设置一次，否则可能引发一些副作用。

import 'package:flutter/services.dart';

类

AssetBundle —— 资源包

方法
- loadString(String key, {bool cache = true}) → Future<String>：加载字符串内容。

MethodChannel —— 平台通道

Flutter侧称为客户端（Client），原生侧称为宿主（Host）。消息的传递是异步的，保证前台UI不会因此而停止响应。发送和接收消息时，序列化和反序列化会自动进行。

构造函数

MethodChannel(
	String name,
	[
	MethodCodec codec = const StandardMethodCodec(),
	BinaryMessenger? binaryMessenger
	]
)

属性
- name → String：通道名称。在单个应用中所有通道名称必需唯一，建议通道名称使用有规律的前缀。
方法
- invokeMethod<T>(String method, [dynamic arguments]) → Future<T?>：调用原生侧的方法。

TextInputType —— 文本输入类型

常量
- datetime → const TextInputType：日期时间。
- emailAddress → const TextInputType：邮箱。
- number → const TextInputType：数字。
- phone → const TextInputType：电话号码。
- text → const TextInputType：文本。
- url → const TextInputType：网址。

枚举

TextInputAction —— 文本输入操作

值
- none → const TextInputAction
- unspecified → const TextInputAction
- done → const TextInputAction
- go → const TextInputAction
- search → const TextInputAction
- send → const TextInputAction
- next → const TextInputAction
- previous → const TextInputAction
- continueAction → const TextInputAction
- join → const TextInputAction
- route → const TextInputAction
- emergencyCall → const TextInputAction
- newline → const TextInputAction

import 'package:flutter/widgets.dart';

函数

runApp —— 运行应用程序

runApp(Widget app) → void

类

AbsorbPointer —— 吞噬指向事件

接收并丢弃事件，子组件无法接收。

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SingleChildRenderObjectWidget > AbsorbPointer

构造函数

AbsorbPointer({
	Key? key,
	bool absorbing = true,
	@Deprecated(
		'Use ExcludeSemantics or create a custom absorb pointer widget instead. '
		'This feature was deprecated after v3.8.0-12.0.pre.'
	)
	bool? ignoringSemantics, Widget? child
})

BottomNavigationBarItem —— 底部导航栏项

构造函数

BottomNavigationBarItem({
	Key? key,
	required Widget icon,
	String? label,
	Widget? activeIcon,
	Color? backgroundColor,
	String? tooltip
})

属性
- icon → Widget
- label → String?

BouncingScrollPhysics —— 气球跳跃式滚动物理效果

继承
Object > ScrollPhysics > BouncingScrollPhysics

构造函数

BouncingScrollPhysics({
	ScrollDecelerationRate decelerationRate = ScrollDecelerationRate.normal,
	ScrollPhysics? parent
})

BuildContext —— 构建上下文

属性
- widget → Widget：对应的组件。

Builder —— 无状态组件构建器

继承
Object > DiagnosticableTree > Widget > StatelessWidget > Builder

构造函数

Builder({
	Key? key,
	required WidgetBuilder builder
})

Center —— 居中

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SingleChildRenderObjectWidget > Align > Center

构造函数

Center({
	Key? key,
	double? widthFactor,
	double? heightFactor,
	Widget? child
})

ClampingScrollPhysics —— 夹紧滚动物理效果

继承
Object > ScrollPhysics > ClampingScrollPhysics

构造函数

ClampingScrollPhysics({ScrollPhysics? parent})

Column —— 列布局/垂直布局

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > MultiChildRenderObjectWidget > Flex > Column

构造函数

Column({
	Key? key,
	MainAxisAlignment mainAxisAlignment = MainAxisAlignment.start,
	MainAxisSize mainAxisSize = MainAxisSize.max,
	CrossAxisAlignment crossAxisAlignment = CrossAxisAlignment.center,
	TextDirection? textDirection,
	VerticalDirection verticalDirection = VerticalDirection.down,
	TextBaseline? textBaseline,
	List<Widget> children = const <Widget>[]
})

属性
- children → List<Widget>：子组件列表。
- crossAxisAlignment → CrossAxisAlignment：交叉轴对齐方式。
- mainAxisAlignment → MainAxisAlignment：主轴对齐方式。当mainAxisSize为MainAxisSize.min时，本属性不起作用，因为空间已被占满。
- mainAxisSize → MainAxisSize：主轴所占空间大小。默认为MainAxisSize.max。
- textDirection → TextDirection?：子组件的水平排布方向。默认跟随系统，大多为TextDirection.ltr。
- verticalDirection → VerticalDirection：子组件的垂直排布方向。默认为VerticalDirection.down。

ConstrainedBox —— 约束盒

当子组件超出最大约束时会显示异常，当子组件未填满最小约束时未填充部分显示背景色。

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SingleChildRenderObjectWidget > ConstrainedBox

构造函数

ConstrainedBox({
	Key? key,
	required BoxConstraints constraints,
	Widget? child
})

属性
- child → Widget?：子组件。
- constraints → BoxConstraints：盒约束条件。

Container —— 容器

继承
Object > DiagnosticableTree > Widget > StatelessWidget > Container

构造函数

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,
	Widget? child,
	Clip clipBehavior = Clip.none
})

属性：
- alignment → AlignmentGeometry?
- child → Widget?
- color → Color?
- constraints → BoxConstraints?
- decoration → Decoration?
- foregroundDecoration → Decoration?
- margin → EdgeInsetsGeometry?：外边距。
- padding → EdgeInsetsGeometry?：内边距。
- transform → Matrix4?

CustomScrollView —— 自定义滚动视图

继承
Object > DiagnosticableTree > Widget > StatelessWidget > ScrollView > CustomScrollView

构造函数

CustomScrollView({
	Key? key,
	Axis scrollDirection = Axis.vertical,
	bool reverse = false,
	ScrollController? controller,
	bool? primary,
	ScrollPhysics? physics,
	ScrollBehavior? scrollBehavior,
	bool shrinkWrap = false,
	Key? center, double anchor = 0.0,
	double? cacheExtent,
	List<Widget> slivers = const <Widget>[],
	int? semanticChildCount,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	ScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
	String? restorationId,
	Clip clipBehavior = Clip.hardEdge,
	HitTestBehavior hitTestBehavior = HitTestBehavior.opaque
})

属性
- slivers → List<Widget>：子组件列表。必须属于Sliver家族。

DecoratedBox —— 装饰盒

为子组件添加视觉效果。

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SingleChildRenderObjectWidget > DecoratedBox

构造函数

DecoratedBox({
	Key? key,
	required Decoration decoration,
	DecorationPosition position = DecorationPosition.background,
	Widget? child
})

属性
- child → Widget?：子组件。
- decoration → Decoration：装饰。
- position → DecorationPosition：装饰相对于子组件的位置。

DefaultAssetBundle —— 默认资源包

继承
Object > DiagnosticableTree > Widget > ProxyWidget > InheritedWidget > DefaultAssetBundle
静态方法
- of(BuildContext context) → AssetBundle：返回构建上下文的资源包。

DefaultTextStyle —— 默认文本样式

其子组件的文本以此为默认文本样式。

继承
Object > DiagnosticableTree > Widget > ProxyWidget > InheritedWidget > InheritedTheme > DefaultTextStyle

构造函数

DefaultTextStyle({
	Key? key,
	required TextStyle style,
	TextAlign? textAlign,
	bool softWrap = true,
	TextOverflow overflow = TextOverflow.clip,
	int? maxLines,
	TextWidthBasis textWidthBasis = TextWidthBasis.parent,
	TextHeightBehavior? textHeightBehavior,
	required Widget child
})

Element —— 元素

可见的。

继承
Object > DiagnosticableTree > Element
构造函数
```
Element(Widget widget)
```

Expanded —— 膨胀

令子组件尽可能地填充可用空间。

继承
Object > DiagnosticableTree > Widget > ProxyWidget > ParentDataWidget<FlexParentData> > Flexible > Expanded

构造函数

Expanded({
	Key? key,
	int flex = 1,
	required Widget child
})

属性
- flex → int：弹性系数。子组件占父组件的比例为：flex/父组件所有子组件的flex之和。

FadeInImage —— 淡入图片

初始显示占位图片，实际图片加载完成后淡入替换。

继承
Object > DiagnosticableTree > Widget > StatefulWidget > FadeInImage

构造函数

FadeInImage.assetNetwork({
	Key? key,
	required String placeholder,
	ImageErrorWidgetBuilder? placeholderErrorBuilder,
	required String image,
	ImageErrorWidgetBuilder? imageErrorBuilder,
	AssetBundle? bundle,
	double? placeholderScale,
	double imageScale = 1.0,
	bool excludeFromSemantics = false,
	String? imageSemanticLabel,
	Duration fadeOutDuration = const Duration(milliseconds: 300),
	Curve fadeOutCurve = Curves.easeOut,
	Duration fadeInDuration = const Duration(milliseconds: 700),
	Curve fadeInCurve = Curves.easeIn,
	double? width,
	double? height,
	BoxFit? fit,
	Color? color,
	BlendMode? colorBlendMode,
	Color? placeholderColor,
	BlendMode? placeholderColorBlendMode,
	BoxFit? placeholderFit,
	FilterQuality filterQuality = FilterQuality.medium,
	FilterQuality? placeholderFilterQuality,
	AlignmentGeometry alignment = Alignment.center,
	ImageRepeat repeat = ImageRepeat.noRepeat,
	bool matchTextDirection = false,
	int? placeholderCacheWidth,
	int? placeholderCacheHeight,
	int? imageCacheWidth,
	int? imageCacheHeight
})

FocusNode —— 焦点

构造函数

FocusNode({
	String? debugLabel,
	@Deprecated(
		'Use onKeyEvent instead. '
		'This feature was deprecated after v3.18.0-2.0.pre.'
	)
	FocusOnKeyCallback? onKey,
	FocusOnKeyEventCallback? onKeyEvent,
	bool skipTraversal = false,
	bool canRequestFocus = true,
	bool descendantsAreFocusable = true,
	bool descendantsAreTraversable = true
})

Form —— 表单

继承
Object > DiagnosticableTree > Widget > StatefulWidget > Form

构造函数

Form({
	Key? key,
	required Widget child,
	bool? canPop,
	@Deprecated(
		'Use onPopInvokedWithResult instead. '
		'This feature was deprecated after v3.22.0-12.0.pre.'
	)
	PopInvokedCallback? onPopInvoked,
	PopInvokedWithResultCallback<Object?>? onPopInvokedWithResult,
	@Deprecated(
		'Use canPop and/or onPopInvokedWithResult instead. '
		'This feature was deprecated after v3.12.0-1.0.pre.'
	)
	WillPopCallback? onWillPop,
	VoidCallback? onChanged,
	AutovalidateMode? autovalidateMode
})

FormState —— 表单状态

继承
Object > State<Form> > FormState
构造函数
```
FormState()
```
方法
- reset() → void：表单重置。
- save() → void：表单保存。
- validate() → bool：表单校验。

FutureBuilder<T> —— Future构建器

继承
Object > DiagnosticableTree > Widget > StatefulWidget > FutureBuilder

构造函数

FutureBuilder({
	Key? key,
	required Future<T>? future,
	T? initialData,
	required AsyncWidgetBuilder<T> builder
})

Flex —— 弹性布局

按比例摆放子组件。要求子组件可以被Expanded包裹。

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > MultiChildRenderObjectWidget > Flex

构造函数

Flex({
	Key? key,
	required Axis direction,
	MainAxisAlignment mainAxisAlignment = MainAxisAlignment.start,
	MainAxisSize mainAxisSize = MainAxisSize.max,
	CrossAxisAlignment crossAxisAlignment = CrossAxisAlignment.center,
	TextDirection? textDirection,
	VerticalDirection verticalDirection = VerticalDirection.down,
	TextBaseline? textBaseline,
	Clip clipBehavior = Clip.none,
	List<Widget> children = const <Widget>[]
})

属性
- direction → Axis：子组件的排布方向。

FormFieldState<T> —— 表单字段状态

继承
Object > State<FormField<T>> > FormFieldState
方法
- reset() → void：重置表单字段至其初始值。
- save() → void：保存。会调用FormField<T>的onSaved方法。
- validate() → bool：校验表单内容。会调用FormField<T>的validator方法。

GestureDetector —— 手势识别

内部使用GestureRecognizer实现。

继承
Object > DiagnosticableTree > Widget > StatelessWidget > GestureDetector

构造函数

GestureDetector({
	Key? key,
	Widget? child,
	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
})

属性
- onDoubleTap → GestureTapCallback?：双击。
- onHorizontalDragDown → GestureDragDownCallback?：水平方向的拖拽按下。
- onHorizontalDragEnd → GestureDragEndCallback?：水平方向的拖拽结束。
- onHorizontalDragUpdate → GestureDragUpdateCallback?：水平方向的拖拽中。
- onLongPress → GestureLongPressCallback?：长按。
- onPanDown → GestureDragDownCallback?：滑动按下。onPanDown与onTap共存时可能只有onPanDown事件响应。
- onPanEnd → GestureDragEndCallback?：滑动结束。
- onPanUpdate → GestureDragUpdateCallback?：滑动中。
- onScaleEnd → GestureScaleEndCallback?：缩放结束。
- onScaleStart → GestureScaleStartCallback?：缩放开始。
- onScaleUpdate → GestureScaleUpdateCallback?：缩放中。
- onTap → GestureTapCallback?：单击。onPanDown与onTap共存时可能只有onPanDown事件响应。
- onVerticalDragDown → GestureDragDownCallback?：垂直方向的拖拽按下。
- onVerticalDragEnd → GestureDragEndCallback?：垂直方向的拖拽结束。
- onVerticalDragUpdate → GestureDragUpdateCallback?：垂直方向的拖拽

GlobalKey<T extends State<StatefulWidget>> —— 全局键

构造函数
```
GlobalKey({String? debugLabel})
```
属性
- currentState → T?：引用此键的对象的当前状态。

GridView —— 滚动网格视图

继承
Object > DiagnosticableTree > Widget > StatelessWidget > ScrollView > BoxScrollView > GridView

构造函数

在有足够简单的子组件的情况下使用：

GridView({
	Key? key,
	Axis scrollDirection = Axis.vertical,
	bool reverse = false,
	ScrollController? controller,
	bool? primary,
	ScrollPhysics? physics,
	bool shrinkWrap = false,
	EdgeInsetsGeometry? padding,
	required SliverGridDelegate gridDelegate,
	bool addAutomaticKeepAlives = true,
	bool addRepaintBoundaries = true,
	bool addSemanticIndexes = true,
	double? cacheExtent,
	List<Widget> children = const <Widget>[],
	int? semanticChildCount,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	Clip clipBehavior = Clip.hardEdge,
	ScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
	String? restorationId,
	HitTestBehavior hitTestBehavior = HitTestBehavior.opaque
})

适合在子组件较多的情况下使用：

GridView.builder({
	Key? key,
	Axis scrollDirection = Axis.vertical,
	bool reverse = false,
	ScrollController? controller,
	bool? primary,
	ScrollPhysics? physics,
	bool shrinkWrap = false,
	EdgeInsetsGeometry? padding,
	required SliverGridDelegate gridDelegate,
	required NullableIndexedWidgetBuilder itemBuilder,
	ChildIndexGetter? findChildIndexCallback,
	int? itemCount,
	bool addAutomaticKeepAlives = true,
	bool addRepaintBoundaries = true,
	bool addSemanticIndexes = true,
	double? cacheExtent,
	int? semanticChildCount,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	ScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
	String? restorationId,
	Clip clipBehavior = Clip.hardEdge,
	HitTestBehavior hitTestBehavior = HitTestBehavior.opaque
})

等价于使用SliverGridDelegateWithFixedCrossAxisCount的快捷实现；

GridView.count({
	Key? key,
	Axis scrollDirection = Axis.vertical,
	bool reverse = false, 
	ScrollController? controller,
	bool? primary,
	ScrollPhysics? physics,
	bool shrinkWrap = false,
	EdgeInsetsGeometry? padding,
	required int crossAxisCount,
	double mainAxisSpacing = 0.0,
	double crossAxisSpacing = 0.0,
	double childAspectRatio = 1.0,
	bool addAutomaticKeepAlives = true,
	bool addRepaintBoundaries = true,
	bool addSemanticIndexes = true,
	double? cacheExtent,
	List<Widget> children = const <Widget>[],
	int? semanticChildCount,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	ScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
	String? restorationId,
	Clip clipBehavior = Clip.hardEdge,
	HitTestBehavior hitTestBehavior = HitTestBehavior.opaque
})

等价于使用SliverGridDelegateWithMaxCrossAxisExtent的快捷实现；

GridView.extent({
	Key? key,
	Axis scrollDirection = Axis.vertical,
	bool reverse = false,
	ScrollController? controller,
	bool? primary,
	ScrollPhysics? physics,
	bool shrinkWrap = false,
	EdgeInsetsGeometry? padding,
	required double maxCrossAxisExtent,
	double mainAxisSpacing = 0.0,
	double crossAxisSpacing = 0.0,
	double childAspectRatio = 1.0,
	bool addAutomaticKeepAlives = true,
	bool addRepaintBoundaries = true,
	bool addSemanticIndexes = true,
	double? cacheExtent, List<Widget> children = const <Widget>[],
	int? semanticChildCount,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	ScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
	String? restorationId,
	Clip clipBehavior = Clip.hardEdge,
	HitTestBehavior hitTestBehavior = HitTestBehavior.opaque
})

属性
- gridDelegate → SliverGridDelegate：用于创建网格的代理。

Hero —— hero动画/共享元素过渡动画

在两个页面之间共同存在的内容的动画。

继承
Object > DiagnosticableTree > Widget > StatefulWidget > Hero

构造函数

Hero({
	Key? key,
	required Object tag,
	CreateRectTween? createRectTween,
	HeroFlightShuttleBuilder? flightShuttleBuilder,
	HeroPlaceholderBuilder? placeholderBuilder,
	bool transitionOnUserGestures = false,
	required Widget child
})

属性
- tag → Object：必需前后一致，这样框架才知道要过渡那个组件。

Icon —— 图标

继承
Object > DiagnosticableTree > Widget > StatelessWidget > Icon

构造函数

Icon(
	IconData? icon,
	{
	Key? key,
	double? size,
	double? fill,
	double? weight,
	double? grade,
	double? opticalSize,
	Color? color,
	List<Shadow>? shadows,
	String? semanticLabel,
	TextDirection? textDirection,
	bool? applyTextScaling
	}
)

IconData —— 图标数据

构造函数

IconData(
	int codePoint,
	{
	String? fontFamily,
	String? fontPackage,
	bool matchTextDirection = false,
	List<String>? fontFamilyFallback
	}
)

IgnorePointer —— 忽略指向事件

不接收事件，但子组件可以接收。

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SingleChildRenderObjectWidget > IgnorePointer

构造函数

IgnorePointer({
	Key? key,
	bool ignoring = true,
	@Deprecated(
		'Use ExcludeSemantics or create a custom ignore pointer widget instead. '
		'This feature was deprecated after v3.8.0-12.0.pre.'
	)
	bool? ignoringSemantics, Widget? child
})

InheritedWidget —— 共享数据继承组件

继承
Object > DiagnosticableTree > Widget > ProxyWidget > InheritedWidget

构造函数

InheritedWidget({Key? key, required Widget child})

方法
- updateShouldNotify(covariant InheritedWidget oldWidget) → bool：通知子组件共享数据是否发生改变。如返回true，子组件中的didChangeDependencies方法会被调用。

Image —— 图片

继承
Object > DiagnosticableTree > Widget > StatefulWidget > Image

构造函数

Image({
	Key? key,
	required ImageProvider\<Object> image,
	ImageFrameBuilder? frameBuilder,
	ImageLoadingBuilder? loadingBuilder,
	ImageErrorWidgetBuilder? errorBuilder,
	String? semanticLabel,
	bool excludeFromSemantics = false,
	double? width,
	double? height,
	Color? color,
	Animation<double>? opacity,
	BlendMode? colorBlendMode,
	BoxFit? fit,
	AlignmentGeometry alignment = Alignment.center,
	ImageRepeat repeat = ImageRepeat.noRepeat,
	Rect? centerSlice,
	bool matchTextDirection = false,
	bool gaplessPlayback = false,
	bool isAntiAlias = false,
	FilterQuality filterQuality = FilterQuality.medium
})

从资源文件夹（于pubspec.yaml中的flutter.assets配置）加载图片：

Image.asset(
	String name,
	{
	Key? key,
	AssetBundle? bundle,
	ImageFrameBuilder? frameBuilder,
	ImageErrorWidgetBuilder? errorBuilder,
	String? semanticLabel,
	bool excludeFromSemantics = false,
	double? scale,
	double? width,
	double? height,
	Color? color,
	Animation<double>? opacity,
	BlendMode? colorBlendMode,
	BoxFit? fit,
	AlignmentGeometry alignment = Alignment.center,
	ImageRepeat repeat = ImageRepeat.noRepeat,
	Rect? centerSlice,
	bool matchTextDirection = false,
	bool gaplessPlayback = false,
	bool isAntiAlias = false,
	String? package,
	FilterQuality filterQuality = FilterQuality.medium,
	int? cacheWidth,
	int? cacheHeight
})

从文件加载图片：

Image.file(
	File file,
	{
	Key? key,
	double scale = 1.0,
	ImageFrameBuilder? frameBuilder,
	ImageErrorWidgetBuilder? errorBuilder,
	String? semanticLabel,
	bool excludeFromSemantics = false,
	double? width,
	double? height,
	Color? color,
	Animation<double>? opacity,
	BlendMode? colorBlendMode,
	BoxFit? fit,
	AlignmentGeometry alignment = Alignment.center,
	ImageRepeat repeat = ImageRepeat.noRepeat,
	Rect? centerSlice,
	bool matchTextDirection = false,
	bool gaplessPlayback = false,
	bool isAntiAlias = false,
	FilterQuality filterQuality = FilterQuality.medium,
	int? cacheWidth,
	int? cacheHeight
})

从网络加载图片：

Image.network(
	String src,
	{
	Key? key,
	double scale = 1.0,
	ImageFrameBuilder? frameBuilder,
	ImageLoadingBuilder? loadingBuilder,
	ImageErrorWidgetBuilder? errorBuilder,
	String? semanticLabel,
	bool excludeFromSemantics = false,
	double? width,
	double? height,
	Color? color,
	Animation<double>? opacity,
	BlendMode? colorBlendMode,
	BoxFit? fit,
	AlignmentGeometry alignment = Alignment.center,
	ImageRepeat repeat = ImageRepeat.noRepeat,
	Rect? centerSlice,
	bool matchTextDirection = false,
	bool gaplessPlayback = false,
	FilterQuality filterQuality = FilterQuality.medium,
	bool isAntiAlias = false,
	Map<String, String>? headers,
	int? cacheWidth,
	int? cacheHeight
	}
)

属性
- height → double?：高度，单位为像素。
- repeat → ImageRepeat：图片重复方式。
- width → double?：宽度，单位为像素。

LeafRenderObjectElement —— 无子组件组件的元素

LeafRenderObjectWidget —— 无子组件组件

Listener —— 事件监听器

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SingleChildRenderObjectWidget > Listener

构造函数

Listener({
	Key? key,
	PointerDownEventListener? onPointerDown,
	PointerMoveEventListener? onPointerMove,
	PointerUpEventListener? onPointerUp,
	PointerHoverEventListener? onPointerHover,
	PointerCancelEventListener? onPointerCancel,
	PointerPanZoomStartEventListener? onPointerPanZoomStart,
	PointerPanZoomUpdateEventListener? onPointerPanZoomUpdate,
	PointerPanZoomEndEventListener? onPointerPanZoomEnd,
	PointerSignalEventListener? onPointerSignal,
	HitTestBehavior behavior = HitTestBehavior.deferToChild,
	Widget? child
})

属性
- behavior → HitTestBehavior：当多个组件重叠时的行为。

ListView —— 滚动列表视图

继承
Object > DiagnosticableTree > Widget > StatelessWidget > ScrollView > BoxScrollView > ListView

构造函数

在有足够简单的子组件的情况下使用：

ListView({
	Key? key,
	Axis scrollDirection = Axis.vertical,
	bool reverse = false,
	ScrollController? controller,
	bool? primary,
	ScrollPhysics? physics,
	bool shrinkWrap = false,
	EdgeInsetsGeometry? padding,
	double? itemExtent,
	ItemExtentBuilder? itemExtentBuilder,
	Widget? prototypeItem,
	bool addAutomaticKeepAlives = true,
	bool addRepaintBoundaries = true,
	bool addSemanticIndexes = true,
	double? cacheExtent,
	List<Widget> children = const <Widget>[],
	int? semanticChildCount,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	ScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
	String? restorationId,
	Clip clipBehavior = Clip.hardEdge,
	HitTestBehavior hitTestBehavior = HitTestBehavior.opaque
})

addAutomaticKeepAlives：是否将每个元素包裹在AutomaticKeepAlive中，令子组件超出屏幕时不会被垃圾回收。默认为true。
addRepaintBoundaries：是否将每个元素包裹在RepaintBoundary中，令元素在第一次显示时被记住，即使滚出屏幕后再显示也无需重新绘制。

内部使用IndexedWidgetBuilder，子组件仅在显示时才会被创建，即懒加载，适合在子组件较多的情况下使用：

ListView.builder({
	Key? key,
	Axis scrollDirection = Axis.vertical,
	bool reverse = false,
	ScrollController? controller,
	bool? primary,
	ScrollPhysics? physics,
	bool shrinkWrap = false,
	EdgeInsetsGeometry? padding,
	double? itemExtent,
	ItemExtentBuilder? itemExtentBuilder,
	Widget? prototypeItem,
	required NullableIndexedWidgetBuilder itemBuilder,
	ChildIndexGetter? findChildIndexCallback,
	int? itemCount,
	bool addAutomaticKeepAlives = true,
	bool addRepaintBoundaries = true,
	bool addSemanticIndexes = true,
	double? cacheExtent,
	int? semanticChildCount,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	ScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
	String? restorationId,
	Clip clipBehavior = Clip.hardEdge,
	HitTestBehavior hitTestBehavior = HitTestBehavior.opaque
})

itemCount：元素数量。null为无限。
itemBuilder：元素创建器。

增加元素间的分隔线：

ListView.separated({
	Key? key,
	Axis scrollDirection = Axis.vertical,
	bool reverse = false,
	ScrollController? controller,
	bool? primary,
	ScrollPhysics? physics,
	bool shrinkWrap = false,
	EdgeInsetsGeometry? padding,
	required NullableIndexedWidgetBuilder itemBuilder,
	ChildIndexGetter? findChildIndexCallback,
	required IndexedWidgetBuilder separatorBuilder,
	required int itemCount,
	bool addAutomaticKeepAlives = true,
	bool addRepaintBoundaries = true,
	bool addSemanticIndexes = true,
	double? cacheExtent,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	ScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
	String? restorationId,
	Clip clipBehavior = Clip.hardEdge,
	HitTestBehavior hitTestBehavior = HitTestBehavior.opaque
})

separatorBuilder：分隔线创建器。

使用SliverChildDelegate提供自定义子组件的额外属性：

ListView.custom({
	Key? key,
	Axis scrollDirection = Axis.vertical,
	bool reverse = false,
	ScrollController? controller,
	bool? primary,
	ScrollPhysics? physics,
	bool shrinkWrap = false,
	EdgeInsetsGeometry? padding,
	double? itemExtent,
	Widget? prototypeItem,
	ItemExtentBuilder? itemExtentBuilder,
	required SliverChildDelegate childrenDelegate,
	double? cacheExtent,
	int? semanticChildCount,
	DragStartBehavior dragStartBehavior = DragStartBehavior.start,
	ScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
	String? restorationId,
	Clip clipBehavior = Clip.hardEdge,
	HitTestBehavior hitTestBehavior = HitTestBehavior.opaque
})

属性
- cacheExtent → double?：超出屏幕的子组件的预载数量。
- childrenDelegate → SliverChildDelegate：用于创建子组件列表的代理。
- controller → ScrollController?：滚动控制器。
- itemExtent → double?：列表元素的大小。对垂直滚动的列表为元素高度，对水平滚动的列表为元素宽度。为了优化性能，通常会指定该值，而不是让框架自己计算。
- shrinkWrap → bool：是否根据所有子组件的长度来计算自身长度。默认为false。通常ListView应沿滚动方向占用尽可能多的空间，仅当其处于一个相同滚动方向且无边界的父组件中并用于处理某些滚动冲突时，设置为true。

Localizations —— 多语言本地化

继承
Object > DiagnosticableTree > Widget > StatefulWidget > Localizations

构造函数

Localizations({
	Key? key,
	required Locale locale,
	required List<LocalizationsDelegate> delegates,
	Widget? child
})

静态方法
- localeOf(BuildContext context) → Locale：获取上下文中的语系区域。
- of<T>(BuildContext context, Type type) → T?：获取上下文中的多语言本地化数据源。

LocalizationsDelegate<T> —— 多语言本地化代理

方法
- isSupported(Locale locale) → bool：是否支持指定的语系区域。
- load(Locale locale) → Future<T>：当语系区域改变时被调用，加载对应的数据。
- shouldReload(covariant LocalizationsDelegate<T> old) → bool：当组件的build方法被调用时，是否重新加载语系资源。通常为false。

MultiChildRenderObjectWidget —— 多子组件组件

属性
- children → List<Widget>：子组件列表。

MultiChildRenderObjectElement —— 多子组件组件的元素

Navigator —— 页面跳转导航

继承
Object > DiagnosticableTree > Widget > StatefulWidget > Navigator

构造函数

Navigator({
	Key? key,
	List<Page> pages = const <Page<dynamic>>[],
	@Deprecated(
		'Use onDidRemovePage instead. '
		'This feature was deprecated after v3.16.0-17.0.pre.'
	)
	PopPageCallback? onPopPage,
	String? initialRoute,
	RouteListFactory onGenerateInitialRoutes = Navigator.defaultGenerateInitialRoutes,
	RouteFactory? onGenerateRoute,
	RouteFactory? onUnknownRoute,
	TransitionDelegate transitionDelegate = const DefaultTransitionDelegate<dynamic>(),
	bool reportsRouteUpdateToEngine = false,
	Clip clipBehavior = Clip.hardEdge,
	List<NavigatorObserver> observers = const <NavigatorObserver>[],
	bool requestFocus = true,
	String? restorationScopeId,
	TraversalEdgeBehavior routeTraversalEdgeBehavior = kDefaultRouteTraversalEdgeBehavior,
	DidRemovePageCallback? onDidRemovePage
})

静态方法
- pop<T extends Object?>(BuildContext context, [T? result]) → void：退出当前页面，返回上一个页面。
- push<T extends Object?>(BuildContext context, Route<T> route) → Future<T?>：跳转动态定义的页面。
- pushNamed<T extends Object?>(BuildContext context, String routeName, {Object? arguments}) → Future<T?>：跳转静态定义的页面。

Notification —— 通知

方法
- dispatch(BuildContext? target) → void：分发通知。

NotificationListener<T extends Notification> —— 通知监听器

通知会逐层上报。

继承
Object > DiagnosticableTree > Widget > ProxyWidget > NotificationListener

构造函数

NotificationListener({
	Key? key,
	required Widget child,
	NotificationListenerCallback<T>? onNotification
})

属性
- onNotification → NotificationListenerCallback<T>?：通知回调。

Padding —— 内边距

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SingleChildRenderObjectWidget > Padding

构造函数

Padding({
	Key? key,
	required EdgeInsetsGeometry padding,
	Widget? child
})

属性
- child → Widget?：子组件。
- padding → EdgeInsetsGeometry：边距。

PerformanceOverlay —— 性能图表

显示GPU和CPU的性能图表。二者的理想状态是每秒60帧，即约16毫秒刷新一帧。

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > LeafRenderObjectWidget > PerformanceOverlay

构造函数

PerformanceOverlay.allEnabled({Key? key})

Positioned —— 定位

继承
Object > DiagnosticableTree > Widget > ProxyWidget > ParentDataWidget<StackParentData> > Positioned

构造函数

Positioned({
	Key? key,
	double? left,
	double? top,
	double? right,
	double? bottom,
	double? width,
	double? height,
	required Widget child
})

left、right、width只可使用其二；top、bottom、height只可使用其二。

属性
- bottom → double?：距离父组件的底部距离。
- height → double?：子组件的高度。
- left → double?：距离父组件的左侧距离。
- right → double?：距离父组件的右侧距离。
- top → double?：距离父组件的顶部距离。
- width → double?：子组件的宽度。

Route<T> —— 路由

构造函数
```
Route({RouteSettings? settings})
```

Row —— 行布局/水平布局

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > MultiChildRenderObjectWidget > Flex > Row

构造函数

Row({
	Key? key,
	MainAxisAlignment mainAxisAlignment = MainAxisAlignment.start,
	MainAxisSize mainAxisSize = MainAxisSize.max,
	CrossAxisAlignment crossAxisAlignment = CrossAxisAlignment.center,
	TextDirection? textDirection,
	VerticalDirection verticalDirection = VerticalDirection.down,
	TextBaseline? textBaseline,
	List<Widget> children = const <Widget>[]
})

属性
- children → List<Widget>：子组件列表。
- crossAxisAlignment → CrossAxisAlignment：交叉轴对齐方式。
- mainAxisAlignment → MainAxisAlignment：主轴对齐方式。当mainAxisSize为MainAxisSize.min时，本属性不起作用，因为空间已被占满。
- mainAxisSize → MainAxisSize：主轴所占空间大小。默认为MainAxisSize.max。
- textDirection → TextDirection?：子组件的水平排布方向。默认跟随系统，大多为TextDirection.ltr。
- verticalDirection → VerticalDirection：子组件的垂直排布方向。默认为VerticalDirection.down。

ScrollController —— 滚动控制器

继承
Object > ChangeNotifier > ScrollController

构造函数

ScrollController({
	double initialScrollOffset = 0.0,
	bool keepScrollOffset = true,
	String? debugLabel,
	ScrollControllerCallback? onAttach,
	ScrollControllerCallback? onDetach
})

方法
- addListener(VoidCallback listener) → void：添加事件监听器。
- animateTo(double offset, {required Duration duration, required Curve curve}) → Future<void>：使用动画滚动。
- jumpTo(double value) → void：不适用动画滚动。

SingleChildRenderObjectWidget —— 单子组件组件

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SingleChildRenderObjectWidget
属性
- child → Widget?：子组件。

SingleChildRenderObjectElement —— 单子组件组件的元素

SingleChildScrollView —— 单个子组件的滚动视图

继承
Object > DiagnosticableTree > Widget > StatelessWidget > SingleChildScrollView

构造函数

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

属性
- child → Widget?：子组件。
- controller → ScrollController?：滚动控制器。
- padding → EdgeInsetsGeometry?：外边距。
- physics → ScrollPhysics?：滚动到尽头后继续滚动的物理效果。
- primary → bool?：是否是主滑块。通常在嵌套其它滚动组件时使用。默认为true。
- reverse → bool：是否反向滚动。默认为false。
- scrollDirection → Axis：滚动的方向。

SizedBox —— 尺寸盒

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SingleChildRenderObjectWidget > SizedBox

构造函数

SizedBox({
	Key? key,
	double? width,
	double? height,
	Widget? child
})

SliverChildBuilderDelegate —— Sliver家族的子组件创建器代理

继承
Object > SliverChildDelegate > SliverChildBuilderDelegate

构造函数

SliverChildBuilderDelegate(
	NullableIndexedWidgetBuilder builder,
	{
	ChildIndexGetter? findChildIndexCallback,
	int? childCount,
	bool addAutomaticKeepAlives = true,
	bool addRepaintBoundaries = true,
	bool addSemanticIndexes = true,
	SemanticIndexCallback semanticIndexCallback = _kDefaultSemanticIndexCallback,
	int semanticIndexOffset = 0
})

方法
- didFinishLayout(int firstIndex, int lastIndex) → void：再绘制完组件时被调用。

SliverFixedExtentList —— Sliver家族的固定尺寸列表

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SliverWithKeepAliveWidget > SliverMultiBoxAdaptorWidget > SliverFixedExtentList

构造函数

SliverFixedExtentList({
	Key? key,
	required SliverChildDelegate delegate,
	required double itemExtent
})

SliverGrid —— Sliver家族的网格

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SliverWithKeepAliveWidget > SliverMultiBoxAdaptorWidget > SliverGrid

构造函数

SliverGrid({
	Key? key,
	required SliverChildDelegate delegate,
	required SliverGridDelegate gridDelegate
})

Stack —— 栈布局/堆叠布局

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > MultiChildRenderObjectWidget > Stack

构造函数

Stack({
	Key? key,
	AlignmentGeometry alignment = AlignmentDirectional.topStart,
	TextDirection? textDirection,
	StackFit fit = StackFit.loose,
	Clip clipBehavior = Clip.hardEdge,
	List<Widget> children = const <Widget>[]
})

属性
- alignment → AlignmentGeometry：对齐。只对没有使用Positioned包裹的子组件或已使用Positioned包裹但没有充足定位信息的子组件使用。
- children → List<Widget>：子组件列表。
- fit → StackFit：对没有定位信息的子组件的尺寸适应方式。
- textDirection → TextDirection?：子组件的水平排布方向。默认跟随系统，大多为TextDirection.ltr。

State<T extends StatefulWidget> —— 状态

构造函数
```
State()
```
方法
- build(BuildContext context) → Widget：构建组件。会在一些其它方法（如：setState）后被自动调用。
- deactivate() → void：从组件树中移除时被调用。
- didChangeDependencies() → void：依赖变更时被调用。
- didUpdateWidget(covariant T oldWidget) → void：重新构建组件时被调用。
- dispose() → void：从组件树中永久销毁时被调用。
- initState() → void：添加至组件树中时被调用。
- reassemble() → void：热重载时被调用。
- setState(VoidCallback fn) → void：设置状态。
属性
- widget → T

StatefulElement —— 有状态元素

继承
Object > DiagnosticableTree > Element > ComponentElement > StatefulElement
构造函数
```
StatefulElement(StatefulWidget widget)
```

StatefulWidget —— 有状态组件

继承
Object > DiagnosticableTree > Widget > StatefulWidget
构造函数
```
StatefulWidget({Key? key})
```
方法
- createElement() → StatefulElement：创建元素。
- createState() → State<StatefulWidget>：创建状态。

StatelessElement —— 无状态元素

继承
Object > DiagnosticableTree > Element > ComponentElement > StatelessElement

构造函数

StatelessElement(StatelessWidget widget)

StatelessWidget —— 无状态组件

继承
Object > DiagnosticableTree > Widget > StatelessWidget
构造函数
```
StatelessWidget({Key? key})
```
方法
- createElement() → StatelessElement：创建元素。
- build() → Widget：构建组件。

Text —— 文本

继承
Object > DiagnosticableTree > Widget > StatelessWidget > Text

构造函数

Text(
	String data, 
	{
	Key? key,
	TextStyle? style,
	StrutStyle? strutStyle,
	TextAlign? textAlign,
	TextDirection? textDirection,
	Locale? locale,
	bool? softWrap,
	TextOverflow? overflow,
	@Deprecated(
		'Use textScaler instead. '
		'Use of textScaleFactor was deprecated in preparation for the upcoming nonlinear text scaling support. '
		'This feature was deprecated after v3.12.0-2.0.pre.'
	)
	double? textScaleFactor,
	TextScaler? textScaler,
	int? maxLines,
	String? semanticsLabel,
	TextWidthBasis? textWidthBasis,
	TextHeightBehavior? textHeightBehavior,
	Color? selectionColor
	}
)

Text.rich(
	InlineSpan textSpan,
	{
	Key? key,
	TextStyle? style,
	StrutStyle? strutStyle,
	TextAlign? textAlign,
	TextDirection? textDirection,
	Locale? locale,
	bool? softWrap,
	TextOverflow? overflow,
	@Deprecated(
		'Use textScaler instead. '
		'Use of textScaleFactor was deprecated in preparation for the upcoming nonlinear text scaling support. '
		'This feature was deprecated after v3.12.0-2.0.pre.'
	)
	double? textScaleFactor,
	TextScaler? textScaler,
	int? maxLines,
	String? semanticsLabel,
	TextWidthBasis? textWidthBasis,
	TextHeightBehavior? textHeightBehavior,
	Color? selectionColor
	}
)

属性
- maxLines → int?：显示的最大行数。默认位自动换行。通常和overflow结合使用。
- overflow → TextOverflow?：文本超出显示范围时的省略方式。
- style → TextStyle?：文本样式。
- textAlign → TextAlign?：文本的对齐方式。

TextEditingController —— 文本编辑控制器

继承
Object > ChangeNotifier > ValueNotifier<TextEditingValue> > TextEditingController

构造函数

TextEditingController({
	String? text
})

属性
- text ↔ String：当前的文本内容。

Transform —— 变换

无论怎样变换，组件的尺寸始终是未变换时的大小。

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > SingleChildRenderObjectWidget > Transform

构造函数

矩阵变换：

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

旋转变换：

Transform.rotate({
	Key? key,
	required double angle,
	Offset? origin,
	AlignmentGeometry? alignment = Alignment.center,
	bool transformHitTests = true,
	FilterQuality? filterQuality,
	Widget? child
})

缩放变换：

Transform.scale({
	Key? key,
	double? scale,
	double? scaleX,
	double? scaleY,
	Offset? origin,
	AlignmentGeometry? alignment = Alignment.center,
	bool transformHitTests = true,
	FilterQuality? filterQuality,
	Widget? child
})

平移变换：

Transform.translate({
	Key? key,
	required Offset offset,
	bool transformHitTests = true,
	FilterQuality? filterQuality,
	Widget? child
})

与交互有关的。

构造函数
```
Widget({Key? key})
```

WillPopScope —— 返回拦截

继承
Object > DiagnosticableTree > Widget > StatefulWidget > WillPopScope

构造函数

WillPopScope({
	Key? key,
	required Widget child,
	required WillPopCallback? onWillPop
})

属性
- child → Widget：弹出提示的组件。
- onWillPop → WillPopCallback?：页面返回时的回调。默认的回调返回Future.value(true)，表示正常推出页面。如回调返回Future.value(false)则不退出，停留在当前页面。

Wrap —— 流式布局

继承
Object > DiagnosticableTree > Widget > RenderObjectWidget > MultiChildRenderObjectWidget > Wrap

构造函数

Wrap({
	Key? key,
	Axis direction = Axis.horizontal,
	WrapAlignment alignment = WrapAlignment.start,
	double spacing = 0.0,
	WrapAlignment runAlignment = WrapAlignment.start,
	double runSpacing = 0.0,
	WrapCrossAlignment crossAxisAlignment = WrapCrossAlignment.start,
	TextDirection? textDirection,
	VerticalDirection verticalDirection = VerticalDirection.down,
	Clip clipBehavior = Clip.none,
	List<Widget> children = const <Widget>[]
})

属性
- alignment → WrapAlignment：主轴方向上子组件的对齐方式。
- direction → Axis：子组件的排布方向。
- runAlignment → WrapAlignment：交叉轴方向上子组件的对齐方式。
- runSpacing → double：交叉轴方向上子组件之间的间距。
- spacing → double：主轴方向上子组件之间的间距。

函数

debugDumpApp —— 转储组件层

需至少构建过一次组件，且不能在build方法执行过程中调用。

void debugDumpApp()

转储信息实际上是把所有组件按树形结构罗列出来。如组件被标记为dirty，表示转储行为是通过该组件触发的。