title: Exception Caught By Widgets Library error in Flutter
body: <p>I have this application in Flutter. It has two classes it spouses to generate a list of notes.</p>
  <p>This is the main class, the MyApp class:</p>
  <pre><code>import 'package:flutter/cupertino.dart';
  import 'package:flutter/material.dart';
  import 'package:notesgenerator/sala.dart';
  
  void main() =&gt; runApp(MyApp());
  
  class MyApp extends StatelessWidget {
    // This widget is the root of your application.
    @override
  
    Widget build(BuildContext context) {
  
      List&lt;Sala&gt; locs = [
        Sala(note: 'Study', noteDes: 'from 6pm ~ 8pm'),
        Sala(note: 'Work', noteDes: 'from 8pm ~ 9pm'),
        Sala(note: 'Play', noteDes: 'from 9pm ~ 9:30pm'),
        Sala(note: 'Eat', noteDes: 'from 9:30pm ~ 10pm'),
      ];
  
      return Scaffold(
        appBar: AppBar(
          title: Text('NoteIndex'),
          centerTitle: true,
        ),
        body: ListView.builder(
            itemCount: 10,
            itemBuilder: (context, index) {
              return Card(
                child: ListTile(
                  onTap: () {},
                  title: (Text(locs[index].note)),
                ),
              );
            }),
      );}}
  </code></pre>
  <p>This is the class that stores the data, the Sala class:</p>
  <pre><code>class Sala {
    String note;
    String noteDes;
    Sala({this.note, this.noteDes});
  }
  </code></pre>
  <p>When I try to run it, I get this:</p>
  <pre><code>I/flutter (21388): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
  I/flutter (21388): The following assertion was thrown building MyApp:
  I/flutter (21388): MediaQuery.of() called with a context that does not contain a MediaQuery.
  I/flutter (21388): No MediaQuery ancestor could be found starting from the context that was passed to MediaQuery.of().
  I/flutter (21388): This can happen because you do not have a WidgetsApp or MaterialApp widget (those widgets introduce
  I/flutter (21388): a MediaQuery), or it can happen if the context you use comes from a widget above those widgets.
  I/flutter (21388): The context used was:
  I/flutter (21388):   Scaffold
  I/flutter (21388): 
  I/flutter (21388): The relevant error-causing widget was:
  I/flutter (21388):   MyApp file:///F:/FlutterProjects/notesgenerator/lib/main.dart:6:23
  I/flutter (21388): 
  I/flutter (21388): When the exception was thrown, this was the stack:
  I/flutter (21388): #0      MediaQuery.of (package:flutter/src/widgets/media_query.dart:798:5)
  I/flutter (21388): #1      ScaffoldState.didChangeDependencies (package:flutter/src/material/scaffold.dart:1993:50)
  I/flutter (21388): #2      StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4376:12)
  I/flutter (21388): #3      ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
  I/flutter (21388): #4      Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
  I/flutter (21388): #5      Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
  I/flutter (21388): #6      ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)
  I/flutter (21388): #7      Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)
  I/flutter (21388): #8      ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4206:5)
  I/flutter (21388): #9      ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
  I/flutter (21388): #10     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
  I/flutter (21388): #11     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
  I/flutter (21388): #12     RenderObjectToWidgetElement._rebuild (package:flutter/src/widgets/binding.dart:1028:16)
  I/flutter (21388): #13     RenderObjectToWidgetElement.mount (package:flutter/src/widgets/binding.dart:999:5)
  I/flutter (21388): #14     RenderObjectToWidgetAdapter.attachToRenderTree.&lt;anonymous closure&gt; (package:flutter/src/widgets/binding.dart:942:17)
  I/flutter (21388): #15     BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2412:19)
  I/flutter (21388): #16     RenderObjectToWidgetAdapter.attachToRenderTree (package:flutter/src/widgets/binding.dart:941:13)
  I/flutter (21388): #17     WidgetsBinding.attachRootWidget (package:flutter/src/widgets/binding.dart:819:7)
  I/flutter (21388): #18     WidgetsBinding.scheduleAttachRootWidget.&lt;anonymous closure&gt; (package:flutter/src/widgets/binding.dart:804:7)
  I/flutter (21388): #27     _Timer._runTimers (dart:isolate-patch/timer_impl.dart:384:19)
  I/flutter (21388): #28     _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:418:5)
  I/flutter (21388): #29     _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:174:12)
  I/flutter (21388): (elided 8 frames from package dart:async and package dart:async-patch)
  I/flutter (21388): 
  I/flutter (21388): ════════════════════════════════════════════════════════════════════════════════════════════════════
  </code></pre>
  <p>If you can help, I will really appreciate it! If you have any questions, please let me know in the comments!</p>