使用BLoC从ListView更改为GridView

class GridBLoC {
  final _items = <String>[];
  final _controller = StreamController<List<String>>.broadcast();

  Stream<List<String>> get itemsStream => _controller.stream;

  void fetchItems() {
    // 从网络或其他数据源获取数据
    // 将数据添加到_items列表中
    // 通过_controller将_items列表发送给订阅者
    _controller.add(_items);
  }

  void dispose() {
    _controller.close();
  }
}

class GridPage extends StatefulWidget {
  @override
  _GridPageState createState() => _GridPageState();
}

class _GridPageState extends State<GridPage> {
  final _bloc = GridBLoC();

  @override
  void initState() {
    super.initState();
    _bloc.fetchItems();
  }

  @override
  void dispose() {
    _bloc.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<List<String>>(
      stream: _bloc.itemsStream,
      builder: (context, snapshot) {
        if (snapshot.hasData) {
          return GridView.builder(
            gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
              crossAxisCount: 2,
            ),
            itemCount: snapshot.data.length,
            itemBuilder: (context, index) {
              return GridTile(
                child: Text(snapshot.data[index]),
              );
            },
          );
        } else if (snapshot.hasError) {
          return Text('Error: ${snapshot.error}');
        } else {
          return CircularProgressIndicator();
        }
      },
    );
  }
}