#8 - BuildContext In-Depth Explanation - Fix BlocProvider.of() fails to find a context containing...
Why Stack Overflow recommends it
Stack Overflow users link it when answering Flutter BLoC errors where a BlocProvider is not found in the current context, such as in modal bottom sheets or after navigation.
Recommended by 2 people across 2 different months, 2022 to 2023.
What it is
A Flutter tutorial from the Flutterly channel, part of a BLoC series, explaining how Flutter builds the widget tree and how BuildContext organizes it. It walks through how BlocProvider.of(context) looks up a provider and how to fix the common "BlocProvider.of() fails to find a context containing a specific bloc" error.
What people said
Recommends Sumit_VE · 2022-01 · Stack Overflow · on “Flutter BlocProvider.of() called with a context that does not contain a Bloc of type”
To use the same bloc in the page you are navigating to use BlocProvider.value(). Change Navigator.push(context, MaterialPageRoute(builder: (context) { return SecondScreen(context); })); to Navigator.push(context, MaterialPageRoute(builder: (context) { return BlocProvider<MyBloc>.value( value: BlocProvider.of<MyBloc>(context), child: SecondScreen(context), ); })); Make sure there is a parent BlocProvider of type MyBloc. Simple Example: BlocProvider<MyBloc>( create: (context) => MyBloc(), child: Builder( builder: (context) => YourWidget(),//Wrap with Builder to access BlocProvider's context ), ); I also highly recommend checking out this video [this video] for better explanation. Also, this issue [
Recommends Taimoor Ghafar · 2023-05 · Stack Overflow · on “Flutter showModalBottomSheet with bloc”
Wrap your outer Container widget with Builder Widget like this child : Builder( builder: (context) { return // Your Container(...); }, ) And also read about BuildContext . This tutorial [this video] will help you to understand BuildContext w.r.t BLOC.
Cites Alex Stroescu · 2022-11 · Stack Overflow · on “Flutter: Could not find the correct Provider<ManageBloc>”
You are providing the BLoC only in the context of "MyHomePage". The Blocs you are trying to provide will go down the widget tree of MyHomePage. When you are displaying the modal bottom sheet, you are actually creating a new context for it, which is not below the MyHomePage widget tree, so the Blocs won't reach the bottom sheet. You have 2 options: Provide the Bloc manually again to the bottom sheet. Refer to Robert Sandberg answer [LINK] Provide the Bloc to the whole app. This means wrapping your MaterialApp with a MultiBlocProvider. This will make your Bloc usable everywhere. return MultiBlocProvider( providers: [ BlocProvider(create: (_) => ManageBloc()), ... ], child: MaterialApp(...), )