No MediaQuery ancestor could be found with MaterialApp available

[skiunke]

Steps to Reproduce

1. Run flutter create bug.

2.Create a basic StatlessWidget

import 'package:flutter/material.dart';

void main() {
  runApp(Bug());
}

class Bug extends StatelessWidget {
  const Bug({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: SafeArea(
        child: Scaffold(
          body: Container(
            height: MediaQuery.of(context).size.height * 0.50,
          ),
        ),
      ),
    );
  }
}

Expected results:
Container with size of 50% of devices height

Actual results:
Exception: No MediaQuery ancestor could be found starting from the context that was passed to MediaQuery.of(). This can happen because you have not added a WidgetsApp, CupertinoApp, or MaterialApp widget (those widgets introduce a MediaQuery), or it can happen if the context you use comes from a widget above those widgets.

Logs

flutter run -d chrome --verbose
[  +47 ms] executing: uname -m
[  +22 ms] Exit code 0 from: uname -m
[        ] x86_64
[   +4 ms] executing: [/home/seby/snap/flutter/common/flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
[   +3 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
[        ] 02c026b03cd31dd3f867e5faeb7e104cce174c5f
[        ] executing: [/home/seby/snap/flutter/common/flutter/] git tag --points-at 02c026b03cd31dd3f867e5faeb7e104cce174c5f
[   +8 ms] Exit code 0 from: git tag --points-at 02c026b03cd31dd3f867e5faeb7e104cce174c5f
[        ] 2.2.1
[   +4 ms] executing: [/home/seby/snap/flutter/common/flutter/] git rev-parse --abbrev-ref --symbolic @{u}
[   +3 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{u}
[        ] origin/stable
[        ] executing: [/home/seby/snap/flutter/common/flutter/] git ls-remote --get-url origin
[   +2 ms] Exit code 0 from: git ls-remote --get-url origin
[        ] https://github.com/flutter/flutter.git
[  +57 ms] executing: [/home/seby/snap/flutter/common/flutter/] git rev-parse --abbrev-ref HEAD
[   +3 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[        ] stable
[  +38 ms] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[   +1 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[  +40 ms] executing: /home/seby/Android/Sdk/platform-tools/adb devices -l
[  +11 ms] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[  +40 ms] executing: /home/seby/Android/Sdk/platform-tools/adb devices -l
[   +7 ms] Skipping pub get: version match.
[  +79 ms] Generating /home/seby/bug/android/app/src/main/java/io/flutter/plugins/GeneratedPluginRegistrant.java
[  +60 ms] List of devices attached
           emulator-5554          device product:sdk_phone_x86 model:Android_SDK_built_for_x86 device:generic_x86 transport_id:2
[   +3 ms] List of devices attached
           emulator-5554          device product:sdk_phone_x86 model:Android_SDK_built_for_x86 device:generic_x86 transport_id:2
[  +37 ms] This application is not configured to build on the web.
[        ] To add web support to a project, run `flutter create .`.
[        ] Launching lib/main.dart on Chrome in debug mode...
[  +67 ms] Updating assets
[  +53 ms] Waiting for connection from debug service on Chrome...
[  +70 ms] <- reset
[   +3 ms] /home/seby/snap/flutter/common/flutter/bin/cache/dart-sdk/bin/dart --disable-dart-dev /home/seby/snap/flutter/common/flutter/bin/cache/artifacts/engine/linux-x64/frontend_server.dart.snapshot --sdk-root /home/seby/snap/flutter/common/flutter/bin/cache/flutter_web_sdk/ --incremental --target=dartdevc
--debugger-module-names --experimental-emit-debug-metadata -DFLUTTER_WEB_AUTO_DETECT=true --output-dill /tmp/flutter_tools.ZZUWRX/flutter_tool.NUINBB/app.dill --libraries-spec file:///home/seby/snap/flutter/common/flutter/bin/cache/flutter_web_sdk/libraries.json --packages
/home/seby/bug/.dart_tool/package_config.json -Ddart.vm.profile=false -Ddart.vm.product=false --enable-asserts --track-widget-creation --filesystem-root /tmp/flutter_tools.ZZUWRX/flutter_tools.GJVMJX --filesystem-scheme org-dartlang-app --initialize-from-dill
build/b1b715402d823b7fd5c2b68d2edcb2ce.cache.dill.track.dill --platform file:///home/seby/snap/flutter/common/flutter/bin/cache/flutter_web_sdk/kernel/flutter_ddc_sdk_sound.dill --sound-null-safety
[   +7 ms] <- compile org-dartlang-app:/web_entrypoint.dart
[+12996 ms] Waiting for connection from debug service on Chrome... (completed in 13.1s)
[        ] Synced 28.2MB.
[        ] <- accept
[        ] Caching compiled dill
[ +122 ms] Using Google Chrome 92.0.4515.159 

[ +227 ms] [CHROME]:
[        ] [CHROME]:DevTools listening on ws://127.0.0.1:32981/devtools/browser/88a26062-8d0d-4311-a43d-52442550168b
[ +202 ms] DwdsInjector: Received request for entrypoint at http://localhost:45295/main_module.bootstrap.js
[   +3 ms] MetadataProvider: Loading debug metadata...
[   +9 ms] MetadataProvider: Loaded debug metadata (sound null safety)
[   +4 ms] DwdsInjector: Injected debugging metadata for entrypoint at http://localhost:45295/main_module.bootstrap.js
[+1201 ms] ChromeProxyService: Initializing expression compiler for main_module.bootstrap.js with sound null safety: true
[  +48 ms] DevHandler: Debug service listening on ws://127.0.0.1:39737/NjobN7PY60U=/ws

[  +16 ms] This app is linked to the debug service: ws://127.0.0.1:39737/NjobN7PY60U=/ws
[   +5 ms] Debug service listening on ws://127.0.0.1:39737/NjobN7PY60U=/ws
[        ] 💪 Running with sound null safety 💪
[   +2 ms] 🔥  To hot restart changes while running, press "r" or "R".
[        ] For a more detailed help message, press "h". To quit, press "q".
[ +891 ms] ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
[        ] The following assertion was thrown building Bug(dirty):
[        ] No MediaQuery widget ancestor found.
[        ] Bug widgets require a MediaQuery widget ancestor.
[  +13 ms] The specific widget that could not find a MediaQuery ancestor was:
[        ]   Bug
[        ] The ownership chain for the affected widget is: "Bug ← [root]"
[        ] No MediaQuery ancestor could be found starting from the context that was passed to MediaQuery.of().
[        ] This can happen because you have not added a WidgetsApp, CupertinoApp, or MaterialApp widget (those
[        ] widgets introduce a MediaQuery), or it can happen if the context you use comes from a widget above
[        ] those widgets.
[        ] The relevant error-causing widget was:
[        ]   Bug file:///home/seby/bug/lib/main.dart:4:10
[        ] When the exception was thrown, this was the stack:
[        ] dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 236:49  throw_
[        ] packages/flutter/src/widgets/debug.dart 219:7                                 <fn>
[        ] packages/flutter/src/widgets/debug.dart 233:12                                debugCheckHasMediaQuery
[        ] packages/flutter/src/widgets/media_query.dart 820:12                          of
[        ] packages/bug/main.dart 12:113                                                 build
[        ] packages/flutter/src/widgets/framework.dart 4648:28                           build
[        ] packages/flutter/src/widgets/framework.dart 4574:15                           performRebuild
[        ] packages/flutter/src/widgets/framework.dart 4267:5                            rebuild
[   +2 ms] packages/flutter/src/widgets/framework.dart 4553:5                            [_firstBuild]
[        ] packages/flutter/src/widgets/framework.dart 4548:5                            mount
[        ] packages/flutter/src/widgets/framework.dart 3611:13                           inflateWidget
[        ] packages/flutter/src/widgets/framework.dart 3363:18                           updateChild
[        ] packages/flutter/src/widgets/binding.dart 1189:16                             [_rebuild]
[        ] packages/flutter/src/widgets/binding.dart 1159:5                              mount
[        ] packages/flutter/src/widgets/binding.dart 1104:16                             <fn>
[        ] packages/flutter/src/widgets/framework.dart 2535:19                           buildScope
[        ] packages/flutter/src/widgets/binding.dart 1103:12                             attachToRenderTree
[        ] packages/flutter/src/widgets/binding.dart 936:24                              attachRootWidget
[        ] packages/flutter/src/widgets/binding.dart 917:7                               <fn>
[        ] dart-sdk/lib/_internal/js_dev_runtime/private/isolate_helper.dart 48:19       internalCallback
[        ] ════════════════════════════════════════════════════════════════════════════════════════════════════

No issues found

[✓] Flutter (Channel stable, 2.2.1, on Linux, locale en_US.UTF-8)
    • Flutter version 2.2.1 at /home/seby/snap/flutter/common/flutter
    • Framework revision 02c026b03c (3 months ago), 2021-05-27 12:24:44 -0700
    • Engine revision 0fdb562ac8
    • Dart version 2.13.1

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
    • Android SDK at /home/seby/Android/Sdk
    • Platform android-31, build-tools 31.0.0
    • Java binary at: /home/seby/.local/share/JetBrains/Toolbox/apps/AndroidStudio/ch-0/203.7621141/jre/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7249189)
    • All Android licenses accepted.

[✓] Chrome - develop for the web
    • Chrome at google-chrome

[✓] Android Studio (version 2020.3)
    • Android Studio at /home/seby/.local/share/JetBrains/Toolbox/apps/AndroidStudio/ch-0/203.7621141
    • Flutter plugin version 59.0.2
    • Dart plugin version 203.8292
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7249189)

[✓] IntelliJ IDEA Ultimate Edition (version 2021.2)
    • IntelliJ at /home/seby/.local/share/JetBrains/Toolbox/apps/IDEA-U/ch-0/212.4746.92
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
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[✓] Connected device (2 available)
    • Android SDK built for x86 (mobile) • emulator-5554 • android-x86    • Android 11 (API 30) (emulator)
    • Chrome (web)                       • chrome        • web-javascript • Google Chrome 92.0.4515.159

• No issues found!

[cedvdb]

it needs to be in a separate widget or in a builder. That's when the context will be accessible. So put your container in a separate widget and it will work.

[skiunke]

That's what I'm usually doing, but why is this the default behaviour of context?

Does MaterialApp return parameters like width and height and therefore the context's width and height is only available in the first "chained" widget?

[TahaTesser]

Hi @SebyKiu
As the error message suggests, there is no MaterialApp as an ancestor, it is a direct child in your case. You need to make it an ancestor so the context contains this information from MaterialApp, see https://api.flutter.dev/flutter/widgets/MediaQuery/of.html

Closing, as this isn't an issue with Flutter itself. If you disagree, please write in the comments and I will reopen it.
Thank you

[cedvdb]

@TahaTesser I was giving OP an answer to his question, maybe you meant to answer him

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.