您应该使用listen()侦听stream，并基于event，您可以emit所需的状态。

yourstream.listen((event) {
      if (event.play)
          emit(First State)
      else
          emit(Second State)
    });

额外：根据提问者的需求

要停止侦听流：

StreamSubscription<Map<PlaceParam, dynamic>> subscription;
subscription = yourstream.listen((event) {
      if (event.play)
          emit(First State)
      else
          emit(Second State)

      ...
   
      subscription.cancel(); 👈 cancel this way
    });

我的最终结果是

enum ConnectionStatus { unknown, connected, disconnected, poor }

class ConnectionCubit extends Cubit<ConnectionStatus> {
  ConnectionCubit() : super(ConnectionStatus.unknown);
  late final StreamSubscription<ConnectivityResult> _streamSubscription;

  void checkConnection() async {
    _streamSubscription = Connectivity().onConnectivityChanged.listen((event) {
      if (event == ConnectivityResult.mobile ||
          event == ConnectivityResult.wifi) {
        emit(ConnectionStatus.connected);
      } else {
        emit(ConnectionStatus.disconnected);
      }
    });
  }

  @override
  Future<void> close() {
    _streamSubscription.cancel();
    return super.close();
  }