无法在flutter中选择文本。
我想在文本字段中选择一个文本，但一直得到一个红色的屏幕，并出现以下错误。
代码：异常：无法选择文本
@override
Widget build(BuildContext context) {
return Scaffold(
floatingActionButtonLocation: FloatingActionButtonLocation.endFloat,
floatingActionButton: UtilUI.getFabExtended(constants.sDone, Icons.check, true, constants, () {
doneNote(context);
}),
appBar: AppBar(
iconTheme: IconThemeData(
color: util.getTheme(context).primaryColorDark,
),
leading: UtilUI.getIconButton(
context, constants, Icons.arrow_back_ios, util.getTheme(context).primaryColorDark, util.getTheme(context).primaryColor, () => {done(context)},
isElevated: false, iconSize: constants.d24),
title: UtilUI.getTextField(_headerController, constants.fHeader16, util.getTheme(context).accentColor, constants.sAddNoteHint,
fontWeight: constants.fWeight8, textAlign: TextAlign.start)),
body: Container(
padding: EdgeInsets.all(constants.d24),
child: Column(mainAxisAlignment: MainAxisAlignment.end, crossAxisAlignment: CrossAxisAlignment.center, children: [
Row(crossAxisAlignment: CrossAxisAlignment.center, mainAxisAlignment: MainAxisAlignment.end, children: [
UtilUI.getIcon(Icons.alarm, util.getTheme(context).primaryColorLight, constants.d24),
SizedBox(width: constants.d4),
Row(children: [UtilUI.getTextDescription(util.timeAgo(_note.time), constants)])
]),
UtilUI.getTextField(_descriptionController, constants.fHeader12, util.getTheme(context).primaryColorLight, constants.sAddNoteHint,
maxLines: constants.i200,
fontWeight: constants.fWeight6,
textAlign: TextAlign.start,
selectionEnabled: true,
copy: true,
cut: true,
paste: true,
selectAll: true)
])));
}
异常：
══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
flutter: The following assertion was thrown building
flutter: _OverlayEntryWidget-[LabeledGlobalKey<_OverlayEntryWidgetState>#ef011](dirty, state:
flutter: _OverlayEntryWidgetState#8dbc7):
flutter: No MediaQuery widget found.
flutter: _OverlayEntryWidget widgets require a MediaQuery widget ancestor.
flutter: The specific widget that could not find a MediaQuery ancestor was:
flutter: _OverlayEntryWidget-[LabeledGlobalKey<_OverlayEntryWidgetState>#ef011]
flutter: The ownership chain for the affected widget is:
flutter: "_OverlayEntryWidget-[LabeledGlobalKey<_OverlayEntryWidgetState>#ef011] ← _Theatre ← Overlay ←
flutter: Directionality ← FlutterEasyLoading ← MyApp ← [root]"
flutter: Typically, the MediaQuery widget is introduced by the MaterialApp or WidgetsApp widget at the top of
flutter: your application widget tree.
flutter:
flutter: The relevant error-causing widget was:
flutter: Overlay
flutter: file:///Users/xx/Library/Flutter/sdk/.pub-cache/hosted/pub.dartlang.org/flutter_easyloading-1.1.4/lib/src/widgets/loading.dart:35:14
flutter:
flutter: When the exception was thrown, this was the stack:
flutter: #0 debugCheckHasMediaQuery.<anonymous closure> (package:flutter/src/widgets/debug.dart:215:7)
flutter: #1 debugCheckHasMediaQuery (package:flutter/src/widgets/debug.dart:227:4)
flutter: #2 _CupertinoTextSelectionControls.buildToolbar (package:flutter/src/cupertino/text_selection.dart:308:12)
flutter: #3 TextSelectionOverlay._buildToolbar (package:flutter/src/widgets/text_selection.dart:556:34)
flutter: #4 _OverlayEntryWidgetState.build (package:flutter/src/widgets/overlay.dart:177:34)
flutter: #5 StatefulElement.build (package:flutter/src/widgets/framework.dart:4619:28)
flutter: #6 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4502:15)
flutter: #7 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4675:11)
flutter: #8 Element.rebuild (package:flutter/src/widgets/framework.dart:4218:5)
flutter: #9 StatefulElement.update (package:flutter/src/widgets/framework.dart:4707:5)
flutter: #10 Element.updateChild (package:flutter/src/widgets/framework.dart:3201:15)
flutter: #11 RenderObjectElement.updateChildren (package:flutter/src/widgets/framework.dart:5522:32)
flutter: #12 MultiChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:5957:17)
flutter: #13 Element.updateChild (package:flutter/src/widgets/framework.dart:3201:15)
flutter: #14 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4527:16)
flutter: #15 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4675:11)
flutter: #16 Element.rebuild (package:flutter/src/widgets/framework.dart:4218:5)
flutter: #17 StatefulElement.update (package:flutter/src/widgets/framework.dart:4707:5)
flutter: #18 Element.updateChild (package:flutter/src/widgets/framework.dart:3201:15)
flutter: #19 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4527:16)
flutter: #20 Element.rebuild (package:flutter/src/widgets/framework.dart:4218:5)
flutter: #21 ProxyElement.update (package:flutter/src/widgets/framework.dart:4862:5)
flutter: #22 Element.updateChild (package:flutter/src/widgets/framework.dart:3201:15)
flutter: #23 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4527:16)
flutter: #24 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4675:11)
flutter: #25 Element.rebuild (package:flutter/src/widgets/framework.dart:4218:5)
flutter: #26 StatefulElement.update (package:flutter/src/widgets/framework.dart:4707:5)
flutter: #27 Element.updateChild (package:flutter/src/widgets/framework.dart:3201:15)
flutter: #28 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4527:16)
flutter: #29 Element.rebuild (package:flutter/src/widgets/framework.dart:4218:5)
flutter: #30 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2627:33)
flutter: #31 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:883:20)
flutter: #32 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:284:5)
flutter: #33 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1113:15)
⣟flutter: #34 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1052:9)
flutter: #35 SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:861:7)
flutter: (elided 4 frames from class _RawReceivePortImpl, class _Timer, and dart:async-patch)
flutter:
你需要有一个 MaterialApp 或 WidgetsApp 在您的当前小组件之上。确保你有 MaterialApp 作为你的应用程序或页面小部件的根。