Flutter Freezed+BLoc 如何从 BLoc Listener 查看当前状态和特定状态的变量

I'm trying to learn how to execute some code in a BLoC listener depending on the state and a code variable that's only present in the success state.
I would like to be able to tell if I'm on the Success state from the Listener, and also, access It's current code

以下是我所在的集团成员国:

@freezed
class ExampleState with _$ExampleState {
  const factory ExampleState.initial() = _Initial;
  const factory ExampleState.success(int code) = _Success;
  const factory ExampleState.error() = _Error;
}

和欧盟

class ExampleBloc extends Bloc<ExampleEvent, ExampleState> {
  ExampleBloc() : super(_Initial()) {
    on<_ChangeCode>((event, emit) {
      if(state is _Success){
        int stateCode = (state as _Success).code;
        debugPrint("Ey, I got the current code:  $stateCode");
        //Would like to access this code variable in a similar way in the listener
      }
      emit(ExampleState.success(event.newCode));
    });
  }
}

最后，这是监听ExampleBloc的监听程序:

listener: (context, state) {
               //Would like to check if the state is success

               //Would like to print something if the state.code == 5
              },

我找到的解决方案如下:

将code变量添加到所有州，这样我就可以执行"state.code"

@freezed
class ExampleState with _$ExampleState {
  const factory ExampleState.initial(int code) = _Initial;
  const factory ExampleState.success(int code) = _Success;
  const factory ExampleState.error(int code) = _Error;
}

然后我可以做:

 listener: (context, state) {
    debugPrint(state.code.toString());
 },

I don't really like this solution as it is really annoying to use on the long run.
-
The other option, would be removing the underscore of the state that I want to check, like so:

@freezed
class ExampleState with _$ExampleState {
  const factory ExampleState.initial() = _Initial;
  const factory ExampleState.success(int code) = Success;
  const factory ExampleState.error() = _Error;
}

然后我可以做:

 listener: (context, state) {
   if(state is Success){
     debugPrint(state.code.toString());
   }
 },

但我不知道Second方法是否是一种糟糕的做法，因为州默认情况下它是私有的，所以也许我不应该删除下划线.