I have code as below, bloc.stateController.stream.listen() not work when data change.
I try to use StreamBuilder but still not work. Please help me. Thank you!:

In task_filter.dart function:

final TaskInfoBloc bloc = TaskInfoBloc();

@override
Widget build(...){
  bloc.stateController.stream.listen((data) {
      setState(() {
        allTasks = data;                  // <====== NOT WORK WHEN CHANGE
      });
    });

    return ...
 }

and:

class TaskInfoBloc {
  final eventController = StreamController<TaskFilterEvents>();
  final stateController = 
      StreamController<List<TaskFilterItemModel>>.broadcast();

  var params = TaskFilterParameterModel();
  var state = TaskFilterState(null);

  TaskInfoBloc() {
    eventController.stream.listen((event) {
      if (event is ChangeTaskFilterStatus) {
        params.taskStatus = event.selected;
      } else {
        /// (event is LoadingData)
        /// Do somethings
      }
      loadData();
    });
  }

  void loadData() async {
    var result = await fetchTaskList(params);
    stateController.add(result);             // <======= CATCH result AND SUCCESS
  }

The code: bloc.stateController.stream.listen() not work when data change.
I try to use StreamBuilder but still not work. Please help me. Thank you!