I am trying to run a QR code reader app on my S7 Edge (Android 7) via Flutter in Android Studio.
Here is a link to the code for the example: https://pub.dartlang.org/packages/qrcode_reader#-example-tab-
When I run the app, it shows up on my phone but if I click the button it gives me this output (includes me trying to click the scan button multiple times to no avail):
PLEASE READ EDIT BELOW
E/flutter (31215): [ERROR:topaz/lib/tonic/logging/dart_error.cc(16)] Unhandled exception:
E/flutter (31215): MissingPluginException(No implementation found for method readQRCode on channel qrcode_reader)
E/flutter (31215): #0 MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:278:7)
E/flutter (31215): <asynchronous suspension>
E/flutter (31215): #1 QRCodeReader.scan (package:qrcode_reader/QRCodeReader.dart:67:27)
E/flutter (31215): <asynchronous suspension>
E/flutter (31215): #2 _MyHomePageState.build.<anonymous closure>.<anonymous closure> (file:///C:/Users/x/AndroidStudioProjects/qr_cod
E/lib/main.dart:56:10)
E/flutter (31215): #3 State.setState (package:flutter/src/widgets/framework.dart:1117:30)
E/flutter (31215): #4 _MyHomePageState.build.<anonymous closure> (file:///C:/Users/x/AndroidStudioProjects/qr_cod
E/lib/main.dart:49:6)
E/flutter (31215): #5 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:494:14)
E/flutter (31215): #6 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:549:30)
E/flutter (31215): #7 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
E/flutter (31215): #8 TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:161:9)
E/flutter (31215): #9 TapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:94:7)
E/flutter (31215): #10 PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:315:9)
E/flutter (31215): #11 PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:73:12)
E/flutter (31215): #12 PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:101:11)
E/flutter (31215): #13 _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:143:19)
E/flutter (31215): #14 _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:121:22)
E/flutter (31215): #15 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:101:7)
E/flutter (31215): #16 _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:64:7)
E/flutter (31215): #17 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:48:7)
E/flutter (31215): #18 _invoke1 (dart:ui/hooks.dart:134:13)
E/flutter (31215): #19 _dispatchPointerDataPacket (dart:ui/hooks.dart:91:5)
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 0
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 1
E/flutter (31215): [ERROR:topaz/lib/tonic/logging/dart_error.cc(16)] Unhandled exception:
E/flutter (31215): MissingPluginException(No implementation found for method readQRCode on channel qrcode_reader)
E/flutter (31215): #0 MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:278:7)
E/flutter (31215): <asynchronous suspension>
E/flutter (31215): #1 QRCodeReader.scan (package:qrcode_reader/QRCodeReader.dart:67:27)
E/flutter (31215): <asynchronous suspension>
E/flutter (31215): #2 _MyHomePageState.build.<anonymous closure>.<anonymous closure> (file:///C:/Users/x/AndroidStudioProjects/qr_cod
E/lib/main.dart:56:10)
E/flutter (31215): #3 State.setState (package:flutter/src/widgets/framework.dart:1117:30)
E/flutter (31215): #4 _MyHomePageState.build.<anonymous closure> (file:///C:/Users/x/AndroidStudioProjects/qr_cod
E/lib/main.dart:49:6)
E/flutter (31215): #5 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:494:14)
E/flutter (31215): #6 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:549:30)
E/flutter (31215): #7 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
E/flutter (31215): #8 TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:161:9)
E/flutter (31215): #9 TapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:94:7)
E/flutter (31215): #10 PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:315:9)
E/flutter (31215): #11 PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:73:12)
E/flutter (31215): #12 PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:101:11)
E/flutter (31215): #13 _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:143:19)
E/flutter (31215): #14 _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:121:22)
E/flutter (31215): #15 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:101:7)
E/flutter (31215): #16 _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:64:7)
E/flutter (31215): #17 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:48:7)
E/flutter (31215): #18 _invoke1 (dart:ui/hooks.dart:134:13)
E/flutter (31215): #19 _dispatchPointerDataPacket (dart:ui/hooks.dart:91:5)
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 0
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 1
E/flutter (31215): [ERROR:topaz/lib/tonic/logging/dart_error.cc(16)] Unhandled exception:
E/flutter (31215): MissingPluginException(No implementation found for method readQRCode on channel qrcode_reader)
E/flutter (31215): #0 MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:278:7)
E/flutter (31215): <asynchronous suspension>
E/flutter (31215): #1 QRCodeReader.scan (package:qrcode_reader/QRCodeReader.dart:67:27)
E/flutter (31215): <asynchronous suspension>
E/flutter (31215): #2 _MyHomePageState.build.<anonymous closure>.<anonymous closure> (file:///C:/Users/x/AndroidStudioProjects/qr_cod
E/lib/main.dart:56:10)
E/flutter (31215): #3 State.setState (package:flutter/src/widgets/framework.dart:1117:30)
E/flutter (31215): #4 _MyHomePageState.build.<anonymous closure> (file:///C:/Users/x/AndroidStudioProjects/qr_cod
E/lib/main.dart:49:6)
E/flutter (31215): #5 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:494:14)
E/flutter (31215): #6 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:549:30)
E/flutter (31215): #7 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
E/flutter (31215): #8 TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:161:9)
E/flutter (31215): #9 TapGestureRecognizer.acceptGesture (package:flutter/src/gestures/tap.dart:123:7)
E/flutter (31215): #10 GestureArenaManager.sweep (package:flutter/src/gestures/arena.dart:156:27)
E/flutter (31215): #11 _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:147:20)
E/flutter (31215): #12 _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:121:22)
E/flutter (31215): #13 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:101:7)
E/flutter (31215): #14 _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:64:7)
E/flutter (31215): #15 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:48:7)
E/flutter (31215): #16 _invoke1 (dart:ui/hooks.dart:134:13)
E/flutter (31215): #17 _dispatchPointerDataPacket (dart:ui/hooks.dart:91:5)
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 0
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 1
E/flutter (31215): [ERROR:topaz/lib/tonic/logging/dart_error.cc(16)] Unhandled exception:
E/flutter (31215): MissingPluginException(No implementation found for method readQRCode on channel qrcode_reader)
E/flutter (31215): #0 MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:278:7)
E/flutter (31215): <asynchronous suspension>
E/flutter (31215): #1 QRCodeReader.scan (package:qrcode_reader/QRCodeReader.dart:67:27)
E/flutter (31215): <asynchronous suspension>
E/flutter (31215): #2 _MyHomePageState.build.<anonymous closure>.<anonymous closure> (file:///C:/Users/x/AndroidStudioProjects/qr_cod
E/lib/main.dart:56:10)
E/flutter (31215): #3 State.setState (package:flutter/src/widgets/framework.dart:1117:30)
E/flutter (31215): #4 _MyHomePageState.build.<anonymous closure> (file:///C:/Users/x/AndroidStudioProjects/qr_cod
E/lib/main.dart:49:6)
E/flutter (31215): #5 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:494:14)
E/flutter (31215): #6 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:549:30)
E/flutter (31215): #7 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
E/flutter (31215): #8 TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:161:9)
E/flutter (31215): #9 TapGestureRecognizer.acceptGesture (package:flutter/src/gestures/tap.dart:123:7)
E/flutter (31215): #10 GestureArenaManager.sweep (package:flutter/src/gestures/arena.dart:156:27)
E/flutter (31215): #11 _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:147:20)
E/flutter (31215): #12 _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:121:22)
E/flutter (31215): #13 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:101:7)
E/flutter (31215): #14 _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:64:7)
E/flutter (31215): #15 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:48:7)
E/flutter (31215): #16 _invoke1 (dart:ui/hooks.dart:134:13)
E/flutter (31215): #17 _dispatchPointerDataPacket (dart:ui/hooks.dart:91:5)
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 0
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 1
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 0
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 1
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 0
D/ViewRootImpl#526fccd[MainActivity](31215): ViewPostImeInputStage processPointer 1
E/flutter (31215): [ERROR:topaz/lib/tonic/logging/dart_error.cc(16)] Unhandled exception:
E/flutter (31215): MissingPluginException(No implementation found for method readQRCode on channel qrcode_reader)
E/flutter (31215): #0 MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:278:7)
E/flutter (31215): <asynchronous suspension>
E/flutter (31215): #1 QRCodeReader.scan (package:qrcode_reader/QRCodeReader.dart:67:27)
E/flutter (31215): <asynchronous suspension>
E/flutter (31215): #2 _MyHomePageState.build.<anonymous closure>.<anonymous closure> (file:///C:/Users/x/AndroidStudioProjects/qr_cod
E/lib/main.dart:56:10)
E/flutter (31215): #3 State.setState (package:flutter/src/widgets/framework.dart:1117:30)
E/flutter (31215): #4 _MyHomePageState.build.<anonymous closure> (file:///C:/Users/x/AndroidStudioProjects/qr_cod
E/lib/main.dart:49:6)
E/flutter (31215): #5 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:494:14)
E/flutter (31215): #6 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:549:30)
E/flutter (31215): #7 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
E/flutter (31215): #8 TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:161:9)
E/flutter (31215): #9 TapGestureRecognizer.acceptGesture (package:flutter/src/gestures/tap.dart:123:7)
E/flutter (31215): #10 GestureArenaManager.sweep (package:flutter/src/gestures/arena.dart:156:27)
E/flutter (31215): #11 _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:147:20)
E/flutter (31215): #12 _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:121:22)
E/flutter (31215): #13 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:101:7)
E/flutter (31215): #14 _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:64:7)
E/flutter (31215): #15 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:48:7)
E/flutter (31215): #16 _invoke1 (dart:ui/hooks.dart:134:13)
E/flutter (31215): #17 _dispatchPointerDataPacket (dart:ui/hooks.dart:91:5)
EDIT:
I restarted my computer to see if that was the issue, since I had only just installed Android Studio on this computer. Now whenever I run the project I get this error
C:\Users\x\Documents\Coding\Flutter\SDK\flutter\.pub-cache\hosted\pub.dartlang.org\qrcode_reader-0.3.3\android\src\main\java\com\matheusvillela\flutter\plugins\qrcodereader\QRCodeReaderPlugin.java:42: error: cannot find symbol public class QRCodeReaderPlugin implements MethodCallHandler, ActivityResultListener, PluginRegistry.RequestPermissionResultListener {
^ symbol: class RequestPermissionResultListener location: interface PluginRegistry C:\Users\x\Documents\Coding\Flutter\SDK\flutter\.pub-cache\hosted\pub.dartlang.org\qrcode_reader-0.3.3\android\src\main\java\com\matheusvillela\flutter\plugins\qrcodereader\QRCodeReaderPlugin.java:63: error: incompatible types: QRCodeReaderPlugin cannot be converted to RequestPermissionsResultListener
registrar.addRequestPermissionsResultListener(instance);
^ C:\Users\x\Documents\Coding\Flutter\SDK\flutter\.pub-cache\hosted\pub.dartlang.org\qrcode_reader-0.3.3\android\src\main\java\com\matheusvillela\flutter\plugins\qrcodereader\QRCodeReaderPlugin.java:155: error: method does not override or implement a method from a supertype
#Override
^ Note: C:\Users\x\Documents\Coding\Flutter\SDK\flutter\.pub-cache\hosted\pub.dartlang.org\qrcode_reader-0.3.3\android\src\main\java\com\matheusvillela\flutter\plugins\qrcodereader\QRCodeReaderPlugin.java uses unchecked or unsafe operations. Note: Recompile with
-Xlint:unchecked for details. Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output 3 errors
FAILURE: Build failed with an exception.
* What went wrong: Execution failed for task ':qrcode_reader:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.
* Try: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
* Get more help at https://help.gradle.org
BUILD FAILED in 2s Finished with error: Gradle build failed: 1
After adding the plugin statement in the pubspec.yaml file, you need to do a flutter packages get command.
Also, you can also try flutter upgrade first. Then check your flutter doctor output.
Sometimes, I also switch Flutter channel as there be be bugs. Change Flutter channel by issuing Flutter channel XXX where XXX is dev, master or beta.
Related
on tap submit subbmit method call .
[1]: https://i.stack.imgur.com/glYah.png
error :
successful
E/flutter (11575): [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: NoSuchMethodError: The method 'readAsBytesSync' was called on null.
E/flutter (11575): Receiver: null
E/flutter (11575): Tried calling: readAsBytesSync()
E/flutter (11575): #0 Object.noSuchMethod (dart:core-patch/object_patch.dart:54:5)
E/flutter (11575): #1 _Delivery_DetailsState.submitForm (package:shop_me/src/screens/product_delivery/ui/delivery_detail.dart:500:37)
E/flutter (11575): #2 _Delivery_DetailsState.build. (package:shop_me/src/screens/product_delivery/ui/delivery_detail.dart:384:33)
E/flutter (11575): #3 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:989:21)
E/flutter (11575): #4 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:182:24)
E/flutter (11575): #5 TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:607:11)
E/flutter (11575): #6 BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:296:5)
E/flutter (11575): #7 BaseTapGestureRecognizer.acceptGesture (package:flutter/src/gestures/tap.dart:267:7)
E/flutter (11575): #8 GestureArenaManager.sweep (package:flutter/src/gestures/arena.dart:157:27)
E/flutter (11575): #9 GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:443:20)
E/flutter (11575): #10 GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:419:22)
E/flutter (11575): #11 RendererBinding.dispatchEvent (package:flutter/src/rendering/binding.dart:287:11)
E/flutter (11575): #12 GestureBinding._handlePointerEventImmediately (package:flutter/src/gestures/binding.dart:374:7)
E/flutter (11575): #13 GestureBinding.handlePointerEvent (package:flutter/src/gestures/binding.dart:338:5)
E/flutter (11575): #14 GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:296:7)
E/flutter (11575): #15 GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:279:7)
E/flutter (11575): #16 _rootRunUnary (dart:async/zone.dart:1370:13)
E/flutter (11575): #17 _CustomZone.runUnary (dart:async/zone.dart:1265:19)
E/flutter (11575): #18 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1170:7)
E/flutter (11575): #19 _invoke1 (dart:ui/hooks.dart:182:10)
E/flutter (11575): #20 PlatformDispatcher._dispatchPointerDataPacket (dart:ui/platform_dispatcher.dart:282:7)
E/flutter (11575): #21 _dispatchPointerDataPacket (dart:ui/hooks.dart:96:31)
E/flutter (11575):
I am new to flutter. when I run my code , I got the error
E/flutter (16181): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: Unhandled error type '() => Future<List<Food>>' is not a subtype of type 'List<Food>' occurred in Instance of 'MenuBloc'.
E/flutter (16181): #0 MenuBloc.mapEventToState (package:restuarant_app/Bloc/menue_bloc/menu_bloc.dart:30:7)
E/flutter (16181): <asynchronous suspension>
E/flutter (16181): #1 Bloc._bindEventsToStates.<anonymous closure> (package:bloc/src/bloc.dart:232:20)
E/flutter (16181): #2 Stream.asyncExpand.onListen.<anonymous closure> (dart:async/stream.dart:579:30)
E/flutter (16181): #3 _rootRunUnary (dart:async/zone.dart:1192:38)
E/flutter (16181): #4 _CustomZone.runUnary (dart:async/zone.dart:1085:19)
E/flutter (16181): #5 _CustomZone.runUnaryGuarded (dart:async/zone.dart:987:7)
E/flutter (16181): #6 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
E/flutter (16181): #7 _DelayedData.perform (dart:async/stream_impl.dart:594:14)
E/flutter (16181): #8 _StreamImplEvents.handleNext (dart:async/stream_impl.dart:710:11)
E/flutter (16181): #9 _PendingEvents.schedule.<anonymous closure> (dart:async/stream_impl.dart:670:7)
E/flutter (16181): #10 _rootRun (dart:async/zone.dart:1180:38)
E/flutter (16181): #11 _CustomZone.run (dart:async/zone.dart:1077:19)
E/flutter (16181): #12 _CustomZone.runGuarded (dart:async/zone.dart:979:7)
E/flutter (16181): #13 _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1019:23)
E/flutter (16181): #14 _rootRun (dart:async/zone.dart:1184:13)
E/flutter (16181): #15 _CustomZone.run (dart:async/zone.dart:1077:19)
E/flutter (16181): #16 _CustomZone.runGuarded (dart:async/zone.dart:979:7)
E/flutter (16181): #17 _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1019:23)
E/flutter (16181): #18 _microtaskLoop (dart:async/schedule_microtask.dart:43:21)
E/flutter (16181): #19 _startMicrotaskLoop (dart:async/schedule_microtask.dart:52:5)
E/flutter (16181):
E/flutter (16181): #0 Cubit.onError.<anonymous closure> (package:bloc/src/cubit.dart:140:7)
E/flutter (16181): #1 Cubit.onError (package:bloc/src/cubit.dart:141:6)
E/flutter (16181): #2 Bloc.onError (package:bloc/src/bloc.dart:113:11)
E/flutter (16181): #3 _rootRunBinary (dart:async/zone.dart:1204:38)
E/flutter (16181): #4 _CustomZone.runBinary (dart:async/zone.dart:1093:19)
E/flutter (16181): #5 _CustomZone.runBinaryGuarded (dart:async/zone.dart:995:7)
E/flutter (16181): #6 _BufferingStreamSubscription._sendError.sendError (dart:async/stream_impl.dart:358:15)
E/flutter (16181): #7 _BufferingStreamSubscription._sendError (dart:async/stream_impl.dart:376:16)
E/flutter (16181): #8 _BufferingStreamSubscription._addError (dart:async/stream_impl.dart:275:7)
E/flutter (16181): #9 _SyncBroadcastStreamController._sendError.<anonymous closure> (dart:async/broadcast_stream_controller.dart:393:20)
E/flutter (16181): #10 _BroadcastStreamController._forEachListener (dart:async/broadcast_stream_controller.dart:327:15)
E/flutter (16181): #11 _SyncBroadcastStreamController._sendError (dart:async/broadcast_stream_controller.dart:392:5)
E/flutter (16181): #12 _BroadcastStreamController._addError (dart:async/broadcast_stream_controller.dart:294:5)
E/flutter (16181): #13 _rootRunBinary (dart:async/zone.dart:1204:38)
E/flutter (16181): #14 _CustomZone.runBinary (dart:async/zone.dart:1093:19)
E/flutter (16181): #15 _CustomZone.runBinaryGuarded (dart:async/zone.dart:995:7)
E/flutter (16181): #16 _BufferingStreamSubscription._sendError.sendError (dart:async/stream_impl.dart:358:15)
E/flutter (16181): #17 _BufferingStreamSubscription._sendError (dart:async/stream_impl.dart:376:16)
E/flutter (16181): #18 _BufferingStreamSubscription._addError (dart:async/stream_impl.dart:275:7)
E/flutter (16181): #19 _ForwardingStreamSubscription._addError (dart:async/stream_pipe.dart:139:11)
E/flutter (16181): #20 _ForwardingStream._handleError (dart:async/stream_pipe.dart:104:10)
E/flutter (16181): #21 _ForwardingStreamSubscription._handleError (dart:async/stream_pipe.dart:170:13)
E/flutter (16181): #22 _rootRunBinary (dart:async/zone.dart:1204:38)
E/flutter (16181): #23 _CustomZone.runBinary (dart:async/zone.dart:1093:19)
E/flutter (16181): #24 _CustomZone.runBinaryGuarded (dart:async/zone.dart:995:7)
E/flutter (16181): #25 _BufferingStreamSubscription._sendError.sendError (dart:async/stream_impl.dart:358:15)
E/flutter (16181): #26 _BufferingStreamSubscription._sendError (dart:async/stream_impl.dart:376:16)
E/flutter (16181): #27 _DelayedError.perform (dart:async/stream_impl.dart:605:14)
E/flutter (16181): #28 _StreamImplEvents.handleNext (dart:async/stream_impl.dart:710:11)
E/flutter (16181): #29 _PendingEvents.schedule.<anonymous closure> (dart:async/stream_impl.dart:670:7)
E/flutter (16181): #30 _rootRun (dart:async/zone.dart:1180:38)
E/flutter (16181): #31 _C
I would like to get data from remote server.I use bloc library in my code.
This is part of menue_bloc.dart .I got error on line allFood= await _foodRepositiry.getAllFood() ;.
class MenuBloc extends Bloc<FoodEvent, MenuState> {
final _foodRepositiry = FoodRepository();
Map<String, List<Food>> mapFoodList;
MenuBloc({this.mapFoodList=const{}}) : super(InitialMenuState());
#override
// TODO: implement initialState
MenuState get initialState => InitialMenuState();
#override
Stream<MenuState> mapEventToState(FoodEvent event) async* {
print("loading....");
yield Loading();
if (event is GetAllFoodEvent) {
print("Get all food....");
this.mapFoodList = {};
List<Food> allFood;
allFood= await _foodRepositiry.getAllFood() ;
try {
print("in menu bloc...... ");
allFood.forEach((food) {
print(food.toString());
if (!this.mapFoodList.containsKey(food.category)) {
this.mapFoodList[food.category.toString()] = [];
}
this.mapFoodList[food.category].add(food);
});
yield Loaded(mapFoodList: this.mapFoodList);
} catch (e, stacktrace) {
print(e.toString());
print(stacktrace.toString());
When I change List<Food> allFood;to Future<List<Food>> allFood; it gives me following error
I/flutter (16181): type '() => Future<List<Food>>' is not a subtype of type 'Future<List<Food>>'
This FoodRepository code.
class FoodRepository{
final foodDao=new FoodDao();
final foodApiClient =new FoodApiClient();
Future getAllFood() async{
if(await checkInternetConnection()) {
print("fetch data from remote server");
return foodApiClient.fetchAllFood;
}else{
print("from db");
return foodDao.getAllFood();
}
}
}
This is FoodApiClient code:
class FoodApiClient{
static const baseUrl = '10.0.2.2';
final http.Client httpClient;
FoodApiClient({this.httpClient});
Future<List<Food>> fetchAllFood()async{
String url=":8080/resturant/food/allFood";
// print(url);
List<Food> foodList;
print(url);
final allFoodResponse=await httpClient.get(baseUrl+url);
print(allFoodResponse);
if (allFoodResponse.statusCode != 200) {
throw Exception('An error occured while loading food list!!! status code: '+allFoodResponse.statusCode.toString());
}
print("foodJson");
List foodJson = json.decode(allFoodResponse.body);
print(foodJson);
//foodJson.forEach((food) {foodList.add(Food.fromJson(food)); });
foodList=foodJson.map((f)=>Food.fromJson(f)).toList();
return foodList;
}
}
Future getAllFood() async{
needs to be
Future<List<Food>> getAllFood() async {
and then you need to follow the compiler errors from there, because there are a lot more instances that I cannot all name and describe here.
I strongly advise you to use proper dart formatting, and the package pedantic to tell you all about your code and how to improve it if you cannot find those places yourself.
The ad loads and is shown successfully the first time but throws an exception if called again.
This is the code snippet for where an interstitial ad is made -
InterstitialAd createInterstitialAd() {
return InterstitialAd(
adUnitId: InterstitialAd.testAdUnitId,
targetingInfo: targetingInfo,
listener: (MobileAdEvent event) {
print("InterstitialAd event $event");
},
);
}
This is the code snippet for where it is called -
if (!(await interstitialAd.isLoaded()))
interstitialAd = createInterstitialAd()..load();
interstitialAd.show();
interstitialAd?.dispose();
interstitialAd = createInterstitialAd()..load();
Error body -
[ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: PlatformException(no_ad_for_id, isAdLoaded failed, no add exists for id=444270692, null)
E/flutter (19241): #0 StandardMethodCodec.decodeEnvelope
package:flutter/…/services/message_codecs.dart:569
E/flutter (19241): #1 MethodChannel._invokeMethod
package:flutter/…/services/platform_channel.dart:156
E/flutter (19241): <asynchronous suspension>
E/flutter (19241): #2 MethodChannel.invokeMethod
package:flutter/…/services/platform_channel.dart:329
E/flutter (19241): #3 _invokeBooleanMethod
package:firebase_admob/firebase_admob.dart:611
E/flutter (19241): #4 MobileAd.isLoaded
package:firebase_admob/firebase_admob.dart:255
E/flutter (19241): #5 buildConsumer.<anonymous closure>.<anonymous closure>
package:compactimg/widgets/select_image_button.dart:56
E/flutter (19241): <asynchronous suspension>
E/flutter (19241): #6 buildConsumer.<anonymous closure>.<anonymous closure> (package:compactimg/widgets/select_image_button.dart)
E/flutter (19241): #7 _InkResponseState._handleTap
package:flutter/…/material/ink_well.dart:779
E/flutter (19241): #8 _InkResponseState.build.<anonymous closure>
package:flutter/…/material/ink_well.dart:862
E/flutter (19241): #9 GestureRecognizer.invokeCallback
package:flutter/…/gestures/recognizer.dart:182
E/flutter (19241): #10 TapGestureRecognizer.handleTapUp
package:flutter/…/gestures/tap.dart:504
E/flutter (19241): #11 BaseTapGestureRecognizer._checkUp
package:flutter/…/gestures/tap.dart:282
E/flutter (19241): #12 BaseTapGestureRecognizer.handlePrimaryPointer
package:flutter/…/gestures/tap.dart:217
E/flutter (19241): #13 PrimaryPointerGestureRecognizer.handleEvent
package:flutter/…/gestures/recognizer.dart:475
E/flutter (19241): #14 PointerRouter._dispatch
package:flutter/…/gestures/pointer_router.dart:76
E/flutter (19241): #15 PointerRouter._dispatchEventToRoutes.<anonymous closure>
package:flutter/…/gestures/pointer_router.dart:122
E/flutter (19241): #16 _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:379:8)
E/flutter (19241): #17 PointerRouter._dispatchEventToRoutes
I'm trying to login in Flutter and this is the error I'm getting when I try to login with a Google email:
E/flutter (26329): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: NoSuchMethodError: The method '[]' was called on null.
`enter code here`E/flutter (26329): Receiver: null
E/flutter (26329): Tried calling: []("email")
E/flutter (26329): #0 Object.noSuchMethod (dart:core-patch/object_patch.dart:53:5)
E/flutter (26329): #1 DocumentSnapshot.[] (package:cloud_firestore/src/document_snapshot.dart:29:42)
E/flutter (26329): #2 new User.fromDocument (package:buddiesgram/models/user.dart:23:17)
E/flutter (26329): #3 _HomePageState.saveUserInfoFirestore (package:buddiesgram/pages/HomePage.dart:83:26)
E/flutter (26329): <asynchronous suspension>
E/flutter (26329): #4 _HomePageState.controlSignIn (package:buddiesgram/pages/HomePage.dart:54:13)
E/flutter (26329): #5 _HomePageState.initState.<anonymous closure> (package:buddiesgram/pages/HomePage.dart:40:9)
E/flutter (26329): #6 _rootRunUnary (dart:async/zone.dart:1192:38)
E/flutter (26329): #7 _CustomZone.runUnary (dart:async/zone.dart:1085:19)
E/flutter (26329): #8 _CustomZone.runUnaryGuarded (dart:async/zone.dart:987:7)
E/flutter (26329): #9 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
E/flutter (26329): #10 _DelayedData.perform (dart:async/stream_impl.dart:594:14)
E/flutter (26329): #11 _StreamImplEvents.handleNext (dart:async/stream_impl.dart:710:11)
E/flutter (26329): #12 _PendingEvents.schedule.<anonymous closure> *emphasized text*(dart:async/stream_impl.dart:670:7)
E/flutter (26329): #13 _rootRun (dart:async/zone.dart:1180:38)
E/flutter (26329): #14 _CustomZone.run (dart:async/zone.dart:1077:19)
E/flutter (26329): #15 _CustomZone.runGuarded (dart:async/zone.dart:979:7)
E/flutter (26329): #16 _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1019:23)`**`*enter code here*`**`
E/flutter (26329): #17 _rootRun (dart:async/zone.dart:1184:13)
E/flutter (26329): #18 _CustomZone.run (dart:async/zone.dart:1077:19)
E/flutter (26329): #19 _CustomZone.runGuarded (dart:async/zone.dart:979:7)
E/flutter (26329): #20 _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1019:23)
E/flutter (26329): #21 _microtaskLoop (dart:async/schedule_microtask.dart:43:21)
E/flutter (26329): #22 _startMicrotaskLoop (dart:async/schedule_microtask.dart:52:5)
E/flutter (26329):
What am I missing?
Please include a code snippet of what you are trying to do
In my understanding of your stackTrace you are trying to call list on a null object like this:
final UserData userData = someObjectHere;
function login(UserData userData){
//The problem is that userData might be null which causes your issue
String email = userData[]("Email");
}
You're solution might be to use null aware operators or to manually check whether the object you're calling a method on is not null.
String email = userData?.[]("Email");
or
if(userData != null) String email = userData?.[]("Email");
I wanted to use google play services in my flutter application for which i used games_services plugin. I followed all the steps in this medium post. But it still gave me this error.
E/flutter (27643): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: PlatformException(error, 4: 4: , null)
E/flutter (27643): #0 StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:569)
E/flutter (27643): #1 MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:321)
E/flutter (27643): <asynchronous suspension>
E/flutter (27643): #2 GamesServices.signIn (package:games_services/games_services.dart:52)
E/flutter (27643): #3 _WelcomePageState.build.<anonymous closure> (package:quizbee/pages/home/welcome.dart:182)
E/flutter (27643): #4 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:706)
E/flutter (27643): #5 _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:789)
E/flutter (27643): #6 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:182)
E/flutter (27643): #7 TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:486)
E/flutter (27643): #8 BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:282)
E/flutter (27643): #9 BaseTapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:199)
E/flutter (27643): #10 PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:467)
E/flutter (27643): #11 PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:76)
E/flutter (27643): #12 PointerRouter._dispatchEventToRoutes.<anonymous closure> (package:flutter/src/gestures/pointer_router.dart:117)
E/flutter (27643): #13 _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:379)
E/flutter (27643): #14 PointerRouter._dispatchEventToRoutes (package:flutter/src/gestures/pointer_router.dart:115)
E/flutter (27643): #15 PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:101)
E/flutter (27643): #16 GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:218)
E/flutter (27643): #17 GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:198)
E/flutter (27643): #18 GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:156)
E/flutter (27643): #19 GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:102)
E/flutter (27643): #20 GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:86)
E/flutter (27643): #21 _rootRunUnary (dart:async/zone.dart:1138)
E/flutter (27643): #22 _CustomZone.runUnary (dart:async/zone.dart:1031)
E/flutter (27643): #23 _CustomZone.runUnaryGuarded (dart:async/zone.dart:933)
E/flutter (27643): #24 _invoke1 (dart:ui/hooks.dart:273)
E/flutter (27643): #25 _dispatchPointerDataPacket (dart:ui/hooks.dart:182)
Thank You in advance.