如何在使用bloc框架时为文本字段指定默认值

class TextFieldBloc extends Bloc<TextFieldEvent, String> {
  TextFieldBloc() : super('');

  @override
  Stream<String> mapEventToState(TextFieldEvent event) async* {
    if (event is TextFieldValueChanged) {
      yield event.value;
    }
  }
}

class MyTextField extends StatelessWidget {
  final TextFieldBloc bloc;

  MyTextField({required this.bloc});

  @override
  Widget build(BuildContext context) {
    return BlocBuilder<TextFieldBloc, String>(
      bloc: bloc,
      builder: (context, state) {
        return TextField(
          onChanged: (value) => bloc.add(TextFieldValueChanged(value)),
          controller: TextEditingController(text: state), // 设置文本字段的默认值
        );
      },
    );
  }
}

void main() {
  final textFieldBloc = TextFieldBloc();
  textFieldBloc.add(TextFieldValueChanged('Default Value'));

  runApp(MyApp(textFieldBloc: textFieldBloc));
}

class MyApp extends StatelessWidget {
  final TextFieldBloc textFieldBloc;

  MyApp({required this.textFieldBloc});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('BLoC TextField Example'),
        ),
        body: Center(
          child: MyTextField(bloc: textFieldBloc),
        ),
      ),
    );
  }
}