错误：未为类型“Bloc”定义设置器“observer”<event, state> '</event,>

Question

I'm using flutter_bloc and according to this example I want to observe the bloc. but I get this error:

error: The setter 'observer' isn't defined for the type 'Bloc<Event, State>'. (undefined_setter at [login_bloc_project] lib\main.dart:12)

when calling this method:

void main() {
  Bloc.observer = MyBlocObserver();
  runApp(MyApp());
}

how can I fix this error?

Answer 1

You can try like this:

  BlocOverrides.runZoned(
    () => runApp(const MyApp()),
    blocObserver: MyBlocObserver(),
  );

Answer 2

Your package version might be lower than v8.1.0. BlocObserver is updated with that version. You can upgrade your dependency to solve this.

For more info: https://bloclibrary.dev/#/migration?id=v810