问颤动Cubit网

EN

class ItemCubit extends Cubit<ItemState> {
  ItemCubit(this._dataBase)
      : super(ItemInitial());
  final DataBase _dataBase;
  StreamSubscription streamSubscription;

  Future<void> pickItemImg() async {
    final currentTempImg =
        await ImagePickerWeb.getImage(outputType: ImageType.bytes);
    emit(ItemImgPicked(currentTempImg));
  }

  Future getItem() async {
    streamSubscription = _dataBase.getItem().listen((data) {
      emit(ItemLoaded(data));
    });
  }
}

@immutable
abstract class ItemState {}

class ItemLoaded extends ItemState {
  final List<Item> item;

  ItemLoaded(this.item);
}

class ItemImgPicked extends ItemState {
  final Uint8List currentTempImg;

  ItemImgPicked(this.currentTempImg);
}

class Page extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        children: [
          RaisedButton(
            onPressed: () async {
              showDialog(
                context: context,
                builder: (BuildContext context) => Dialog(
                  child: Container(
                    width: 400,
                    child: OutlineButton(
                      onPressed: () async {
                        context.bloc<ItemCubit>().pickProductImg();
                      },
                      child: BlocBuilder<ItemCubit, ItemState>(
                        builder: (context, state) {
                          if (state is ItemImgPicked) {
                            return Image.memory(state.currentTempImg);
                          } else {
                            return Container();
                          }
                        },
                      ),
                    ),
                  ),
                ),
              );
            },
            child: Text('add'),
          ),
          BlocBuilder<ItemCubit, ItemState>(
            builder: (context, state) {
              if (state is ItemLoaded) {
                return Column(
                  children: state.item.map(
                    (item) {
                      return Text(item.name);
                    },
                  ).toList(),
                );
              }
              return CircularProgressIndicator();
            },
          )
        ],
      ),
    );
  }
}