从BlocBuilder导航到新屏幕

Question

I am trying to navigate to a new page, when my bloc is in a specific state. However right now whenver I am trying to do this I get the following error:

I/flutter (25673): Another exception was thrown: setState() or markNeedsBuild() called during build.

In the code down below I am doing some dispatches, here I am also checking if the current state of one of my blocs are something specific, then navigate to a new screen.

if (state is Finished) {
      startOver(timerBloc, counterBloc, spotifyBloc, context);
      return [];
    }

My question is; is there anyway to navigate to a new screen from a BlocBuilder?

What i've tried: I have tried to give different contexts, passing it down, and even making it within its own class.

All classes are stateless.

The whole bloc can be seen in this pastebin .

Answer 1

You should avoid placing any 'actions' within the build statement... I would use a StatefulWidget and place those actions in the initState(). However, since you are using Flutter Bloc package(felangel.github.io/bloc), you can use BlocListener as an alternative.

Something like this:

class Actions extends StatelessWidget {
AudioPlayer audioPlayer = new AudioPlayer();

@override
Widget build(BuildContext context) {

   final TimerBloc timerBloc = BlocProvider.of<TimerBloc>(context);
   return BlocListener<TimerBloc, TimerState>(
     listener: (context, state) {

       if (state is Finished) {
           startOver(timerBloc, counterBloc, spotifyBloc, context);
       }

     },
     child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        children: _mapStateToActionButtons(
          timerBloc: BlocProvider.of<TimerBloc>(context),
          counterBloc: BlocProvider.of<CounterBloc>(context),
          spotifyBloc: BlocProvider.of<SpotifyBloc>(context),
          adBloc: BlocProvider.of<AdBloc>(context),
        ),
   );

}