Flutter （使用不包含MediaQuery的上下文调用MediaQuery.of（））错误
我的颤振代码是， 此代码通过导出Adobe XD文件并使用默认的Flutter （使用不包含MediaQuery的上下文调用MediaQuery.of（））错误,flutter,dart,Flutter,Dart,我的颤振代码是， 此代码通过导出Adobe XD文件并使用默认的main.dart添加来编写 代码通过Adobe XD生成，并通过导出将其放入VS代码中。 它在调试控制台中显示此错误 请帮助输入此代码 import 'package:flutter/material.dart'; import 'package:flutter_svg/flutter_svg.dart'; import 'package:adobe_xd/blend_mask.dart'; void main() { ru
main.dart添加来编写
代码通过Adobe XD生成，并通过导出将其放入VS代码中。
它在调试控制台中显示此错误
请帮助输入此代码
import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:adobe_xd/blend_mask.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: const Color(0xffffffff),
body: Stack(
children: <Widget>[
Transform.translate(
offset: Offset(-6.0, -9.0),
child: SvgPicture.string(
_svg_hscwvz,
allowDrawingOutsideViewBox: true,
),
),
Transform.translate(
offset: Offset(-48.0, 65.0),
child: SizedBox(
width: 424.0,
height: 266.0,
child: Text.rich(
TextSpan(
style: TextStyle(
fontFamily: 'Google Sans',
fontSize: 30,
color: const Color(0xff707070),
),
children: [
TextSpan(
text: ' ',
),
TextSpan(
text: 'DO YOU KNOW?\n',
style: TextStyle(
fontWeight: FontWeight.w700,
),
),
TextSpan(
text:
'\n YOU CAN BETTER THE\n PERFORMANCE OF YOUR\n EARPHONE BY 63%.\n\n JUST BY USING THIS APP',
),
],
),
textAlign: TextAlign.center,
),
),
),
Transform.translate(
offset: Offset(18.0, 433.0),
child: SizedBox(
width: 14.0,
child: Text(
'',
style: TextStyle(
fontFamily: 'Google Sans',
fontSize: 30,
color: const Color(0xff707070),
),
textAlign: TextAlign.center,
),
),
),
Transform.translate(
offset: Offset(103.0, 402.0),
child: SizedBox(
width: 206.0,
height: 114.0,
child: Text(
'JUST FOLLOW \nTHESE SIMPLE \nSTEPS …',
style: TextStyle(
fontFamily: 'Google Sans',
fontSize: 30,
color: const Color(0xff707070),
),
textAlign: TextAlign.center,
),
),
),
// Adobe XD layer: 'graphs' (group)
BlendMask(
blendMode: BlendMode.multiply,
opacity: 1,
region: Offset(-64.0, 554.9) & Size(495.0, 149.2),
child: Stack(
children: <Widget>[
Transform.translate(
offset: Offset(-64.0, 554.86),
child: SvgPicture.string(
_svg_6t608q,
allowDrawingOutsideViewBox: true,
),
),
],
),
),
],
),
);
return MaterialApp(
title: 'Ehtasham app',
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
// This makes the visual density adapt to the platform that you run
// the app on. For desktop platforms, the controls will be smaller and
// closer together (more dense) than on mobile platforms.
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
// This call to setState tells the Flutter framework that something has
// changed in this State, which causes it to rerun the build method below
// so that the display can reflect the updated values. If we changed
// _counter without calling setState(), then the build method would not be
// called again, and so nothing would appear to happen.
_counter++;
});
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: Column(
// Column is also a layout widget. It takes a list of children and
// arranges them vertically. By default, it sizes itself to fit its
// children horizontally, and tries to be as tall as its parent.
//
// Invoke "debug painting" (press "p" in the console, choose the
// "Toggle Debug Paint" action from the Flutter Inspector in Android
// Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
// to see the wireframe for each widget.
//
// Column has various properties to control how it sizes itself and
// how it positions its children. Here we use mainAxisAlignment to
// center the children vertically; the main axis here is the vertical
// axis because Columns are vertical (the cross axis would be
// horizontal).
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
const String _svg_hscwvz =
'<svg viewBox="-6.0 -9.0 424.0 866.0" ><defs><linearGradient id="gradient" x1="0.5" y1="0.2911" x2="0.5" y2="1.0"><stop offset="0.0" stop-color="#ff4fffb7" /><stop offset="1.0" stop-color="#ff5173fb" /><stop offset="1.0" stop-color="#ff76998b" /><stop offset="1.0" stop-color="#ff808080" /></linearGradient></defs><path transform="translate(-6.0, -9.0)" d="M 0 0 L 424 0 L 424 866 L 0 866 L 0 0 Z" fill="url(#gradient)" stroke="#090909" stroke-width="1" stroke-miterlimit="4" stroke-linecap="butt" /></svg>';
const String _svg_6t608q =
'<svg viewBox="-64.0 554.9 495.0 149.2" ><path transform="translate(-1146.85, -6457.22)" d="M 1533.19384765625 7060.17333984375 C 1464.86669921875 7058.81982421875 1463.255249023438 7082.07958984375 1418.307250976562 7082.07958984375 C 1373.359252929688 7082.07958984375 1346.678833007812 7047.59765625 1300.068969726562 7047.59765625 C 1253.459106445312 7047.59765625 1239.491333007812 7052.82373046875 1189.326782226562 7052.82373046875 C 1139.162231445312 7052.82373046875 1082.85009765625 7012.07958984375 1082.85009765625 7012.07958984375 C 1082.85009765625 7012.07958984375 1082.85009765625 7161.27685546875 1082.85009765625 7161.27685546875 C 1082.85009765625 7161.27685546875 1533.19384765625 7161.27685546875 1533.19384765625 7161.27685546875 C 1533.19384765625 7161.27685546875 1533.19384765625 7060.17333984375 1533.19384765625 7060.17333984375 Z" fill="none" fill-opacity="0.05" stroke="#2699fb" stroke-width="10" stroke-opacity="0.05" stroke-miterlimit="4" stroke-linecap="butt" /><path transform="translate(-1150.85, -6434.0)" d="M 1533.19384765625 7062.5625 C 1464.86669921875 7061.75927734375 1470.591186523438 7037.07421875 1425.643188476562 7037.07421875 C 1380.695190429688 7037.07421875 1362.970458984375 7074.9140625 1295.2060546875 7074.9140625 C 1258.198974609375 7074.9140625 1227.359741210938 7037.07421875 1193.514282226562 7037.07421875 C 1159.668579101562 7037.07421875 1112.85009765625 7054.0546875 1112.85009765625 7054.0546875 C 1112.85009765625 7054.0546875 1112.85009765625 7109.0546875 1112.85009765625 7109.0546875 C 1112.85009765625 7109.0546875 1533.19384765625 7109.0546875 1533.19384765625 7109.0546875 C 1533.19384765625 7109.0546875 1533.19384765625 7062.5625 1533.19384765625 7062.5625 Z" fill="none" fill-opacity="0.2" stroke="#2699fb" stroke-width="5" stroke-opacity="0.2" stroke-miterlimit="4" stroke-linecap="butt" /><path transform="translate(-1181.85, -6419.0)" d="M 1142.850219726562 7049.0546875 C 1221.619995117188 7048.25146484375 1220.568115234375 7001.95703125 1272.385375976562 7001.95703125 C 1324.20263671875 7001.95703125 1339.0888671875 7071.9140625 1417.209594726562 7071.9140625 C 1472.696044921875 7071.9140625 1491.203125 7032.0546875 1530.221313476562 7032.0546875 C 1569.239501953125 7032.0546875 1612.850219726562 7049.0546875 1612.850219726562 7049.0546875 C 1612.850219726562 7049.0546875 1612.850219726562 7109.0546875 1612.850219726562 7109.0546875 C 1612.850219726562 7109.0546875 1142.850219726562 7109.0546875 1142.850219726562 7109.0546875 C 1142.850219726562 7109.0546875 1142.850219726562 7049.0546875 1142.850219726562 7049.0546875 Z" fill="none" fill-opacity="0.5" stroke="#2699fb" stroke-width="2" stroke-opacity="0.5" stroke-miterlimit="4" stroke-linecap="butt" /></svg>';
I/flutter (24258): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter (24258): The following assertion was thrown building MyApp:
I/flutter (24258): MediaQuery.of() called with a context that does not contain a MediaQuery.
I/flutter (24258): No MediaQuery ancestor could be found starting from the context that was passed to MediaQuery.of().
I/flutter (24258): This can happen because you do not have a WidgetsApp or MaterialApp widget (those widgets introduce
I/flutter (24258): a MediaQuery), or it can happen if the context you use comes from a widget above those widgets.
I/flutter (24258): The context used was:
I/flutter (24258): Scaffold
I/flutter (24258):
I/flutter (24258): The relevant error-causing widget was:
I/flutter (24258): MyApp
lib\main.dart:6
I/flutter (24258):
I/flutter (24258): When the exception was thrown, this was the stack:
I/flutter (24258): ... Normal element mounting (7 frames)
I/flutter (24258): (elided 11 frames from class _RawReceivePortImpl, class _Timer, dart:async, and dart:async-patch)
I/flutter (24258):
I/flutter (24258): ════════════════════════════════════════════════════════════════════════════════════════════════════
代码通过Adobe XD生成，并通过导出放入VS代码。您需要将生成的代码放入Material app中。我将所有代码移动到MyHomePage
import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:adobe_xd/blend_mask.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Ehtasham app',
theme: ThemeData(
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: const Color(0xffffffff),
body: Stack(
children: <Widget>[
Transform.translate(
offset: Offset(-6.0, -9.0),
child: SvgPicture.string(
_svg_hscwvz,
allowDrawingOutsideViewBox: true,
),
),
Transform.translate(
offset: Offset(-48.0, 65.0),
child: SizedBox(
width: 424.0,
height: 266.0,
child: Text.rich(
TextSpan(
style: TextStyle(
fontFamily: 'Google Sans',
fontSize: 30,
color: const Color(0xff707070),
),
children: [
TextSpan(
text: ' ',
),
TextSpan(
text: 'DO YOU KNOW?\n',
style: TextStyle(
fontWeight: FontWeight.w700,
),
),
TextSpan(
text:
'\nYOU CAN BETTER THE\n PERFORMANCE OF YOUR\n EARPHONE BY 63%.\n\n JUST BY USING THIS APP',
),
],
),
textAlign: TextAlign.center,
),
),
),
Transform.translate(
offset: Offset(18.0, 433.0),
child: SizedBox(
width: 14.0,
child: Text(
'',
style: TextStyle(
fontFamily: 'Google Sans',
fontSize: 30,
color: const Color(0xff707070),
),
textAlign: TextAlign.center,
),
),
),
Transform.translate(
offset: Offset(103.0, 402.0),
child: SizedBox(
width: 206.0,
height: 114.0,
child: Text(
'JUST FOLLOW \nTHESE SIMPLE \nSTEPS …',
style: TextStyle(
fontFamily: 'Google Sans',
fontSize: 30,
color: const Color(0xff707070),
),
textAlign: TextAlign.center,
),
),
),
// Adobe XD layer: 'graphs' (group)
BlendMask(
blendMode: BlendMode.multiply,
opacity: 1,
region: Offset(-64.0, 554.9) & Size(495.0, 149.2),
child: Stack(
children: <Widget>[
Transform.translate(
offset: Offset(-64.0, 554.86),
child: SvgPicture.string(
_svg_6t608q,
allowDrawingOutsideViewBox: true,
),
),
],
),
),
],
),
);
}
}
const String _svg_hscwvz =
'<svg viewBox="-6.0 -9.0 424.0 866.0" ><defs><linearGradient id="gradient" x1="0.5" y1="0.2911" x2="0.5" y2="1.0"><stop offset="0.0" stop-color="#ff4fffb7" /><stop offset="1.0" stop-color="#ff5173fb" /><stop offset="1.0" stop-color="#ff76998b" /><stop offset="1.0" stop-color="#ff808080" /></linearGradient></defs><path transform="translate(-6.0, -9.0)" d="M 0 0 L 424 0 L 424 866 L 0 866 L 0 0 Z" fill="url(#gradient)" stroke="#090909" stroke-width="1" stroke-miterlimit="4" stroke-linecap="butt" /></svg>';
const String _svg_6t608q =
'<svg viewBox="-64.0 554.9 495.0 149.2" ><path transform="translate(-1146.85, -6457.22)" d="M 1533.19384765625 7060.17333984375 C 1464.86669921875 7058.81982421875 1463.255249023438 7082.07958984375 1418.307250976562 7082.07958984375 C 1373.359252929688 7082.07958984375 1346.678833007812 7047.59765625 1300.068969726562 7047.59765625 C 1253.459106445312 7047.59765625 1239.491333007812 7052.82373046875 1189.326782226562 7052.82373046875 C 1139.162231445312 7052.82373046875 1082.85009765625 7012.07958984375 1082.85009765625 7012.07958984375 C 1082.85009765625 7012.07958984375 1082.85009765625 7161.27685546875 1082.85009765625 7161.27685546875 C 1082.85009765625 7161.27685546875 1533.19384765625 7161.27685546875 1533.19384765625 7161.27685546875 C 1533.19384765625 7161.27685546875 1533.19384765625 7060.17333984375 1533.19384765625 7060.17333984375 Z" fill="none" fill-opacity="0.05" stroke="#2699fb" stroke-width="10" stroke-opacity="0.05" stroke-miterlimit="4" stroke-linecap="butt" /><path transform="translate(-1150.85, -6434.0)" d="M 1533.19384765625 7062.5625 C 1464.86669921875 7061.75927734375 1470.591186523438 7037.07421875 1425.643188476562 7037.07421875 C 1380.695190429688 7037.07421875 1362.970458984375 7074.9140625 1295.2060546875 7074.9140625 C 1258.198974609375 7074.9140625 1227.359741210938 7037.07421875 1193.514282226562 7037.07421875 C 1159.668579101562 7037.07421875 1112.85009765625 7054.0546875 1112.85009765625 7054.0546875 C 1112.85009765625 7054.0546875 1112.85009765625 7109.0546875 1112.85009765625 7109.0546875 C 1112.85009765625 7109.0546875 1533.19384765625 7109.0546875 1533.19384765625 7109.0546875 C 1533.19384765625 7109.0546875 1533.19384765625 7062.5625 1533.19384765625 7062.5625 Z" fill="none" fill-opacity="0.2" stroke="#2699fb" stroke-width="5" stroke-opacity="0.2" stroke-miterlimit="4" stroke-linecap="butt" /><path transform="translate(-1181.85, -6419.0)" d="M 1142.850219726562 7049.0546875 C 1221.619995117188 7048.25146484375 1220.568115234375 7001.95703125 1272.385375976562 7001.95703125 C 1324.20263671875 7001.95703125 1339.0888671875 7071.9140625 1417.209594726562 7071.9140625 C 1472.696044921875 7071.9140625 1491.203125 7032.0546875 1530.221313476562 7032.0546875 C 1569.239501953125 7032.0546875 1612.850219726562 7049.0546875 1612.850219726562 7049.0546875 C 1612.850219726562 7049.0546875 1612.850219726562 7109.0546875 1612.850219726562 7109.0546875 C 1612.850219726562 7109.0546875 1142.850219726562 7109.0546875 1142.850219726562 7109.0546875 C 1142.850219726562 7109.0546875 1142.850219726562 7049.0546875 1142.850219726562 7049.0546875 Z" fill="none" fill-opacity="0.5" stroke="#2699fb" stroke-width="2" stroke-opacity="0.5" stroke-miterlimit="4" stroke-linecap="butt" /></svg>';
导入“包装：颤振/材料.省道”；
导入“package:flatter_svg/flatter_svg.dart”；
导入“package:adobe_xd/blend_mask.dart”；
void main（）{
runApp（MyApp（））；
}
类MyApp扩展了无状态小部件{
@凌驾
小部件构建（构建上下文）{
返回材料PP(
标题：“Ehtasham应用程序”，
主题：主题数据(
视觉密度：视觉密度。自适应平台密度，
),
主页：MyHomePage（），
);
}
}
类MyHomePage扩展StatefulWidget{
@凌驾
_MyHomePageState createState（）=>\u MyHomePageState（）；
}
类_MyHomePageState扩展状态{
@凌驾
小部件构建（构建上下文）{
返回脚手架(
背景颜色：常量颜色（0xFFFFFF），
主体：堆栈(
儿童：[
转换(
偏移量：偏移量（-6.0，-9.0），
子项：SvgPicture.string(
_svg_hscwvz，
allowDrawingOutsideViewBox:true，
),
),
转换(
偏移量：偏移量（-48.0,65.0），
孩子：大小盒子(
宽度：424.0，
身高：266.0，
孩子：Text.rich(
TextSpan(
样式：TextStyle(
fontFamily:“谷歌SAN”，
尺寸：30，
颜色：常量颜色（0xff707070），
),
儿童：[
TextSpan(
文本：“”，
),
TextSpan(
文本：“你知道吗？\n”，
样式：TextStyle(
fontWeight:fontWeight.w700，
),
),
TextSpan(
正文：
“\n您可以将耳机的性能\n提高63%。\n\n仅使用此应用程序”，
),
],
),
textAlign:textAlign.center，
),
),
),
转换(
偏移量：偏移量（18.0433.0），
孩子：大小盒子(
宽度：14.0，
子：文本(
'',
样式：TextStyle(
fontFamily:“谷歌SAN”，
尺寸：30，
颜色：常量颜色（0xff707070），
),
textAlign:textAlign.center，
),
),
),
转换(
偏移量：偏移量（103.0402.0），
孩子：大小盒子(
宽度：206.0，
身高：114.0，
子：文本(
'只需遵循这些简单的步骤即可…'，
样式：TextStyle(
fontFamily:“谷歌SAN”，
尺寸：30，
颜色：常量颜色（0xff707070），
),
textAlign:textAlign.center，
),
),
),
//Adobe XD层：“图形”（组）
混合任务(
blendMode:blendMode.multiply，
不透明度：1，
地区：偏移量（-64.0554.9）和大小（495.0149.2），
子：堆栈(
儿童：[
转换(
偏移量：偏移量（-64.0554.86），
子项：SvgPicture.string(
_svg_6t608q，
allowDrawingOutsideViewBox:true，
),
),
],
),
),
],
),
);
}
}
常量字符串_svg_hscwvz=
'';
常量字符串_svg_6t608q=
'';