Flutter集成带过滤器的Algolia搜索时遭遇‘fromResponse未找到’错误的求助

大家好，我正在尝试在Flutter中实现带过滤器的Algolia搜索功能。我严格按照Algolia官方的一篇文章一步步操作，现在到了这个阶段，但运行程序时遇到了两个报错，完全不知道该怎么解决，希望大家能帮我看看：

错误信息 #

lib/services/search.dart:194:52: Error: Member not found: 'fromResponse'.

_assetsSearcher.responses.map(SearchMetadata.fromResponse);

^^^^^^^^^^^^

lib/services/search.dart:200:46: Error: Member not found: 'fromResponse'.

_assetsSearcher.responses.map(HitsPage.fromResponse);

^^^^^^^^^^^^

我的代码 #

class SearchMetadata {

final int nbHits;

const SearchMetadata(this.nbHits);

factory SearchMetadata.fromResponse(SearchResponse response) =>
SearchMetadata(response.nbHits);

}

class Asset {

final String code;
final String name;
final String desc;
final String loc;
final String img;

Asset(this.code, this.name, this.desc, this.loc, this.img);

static Asset fromJson(Map<String, dynamic> json) {
return Asset(
json['name'], json['desc'], json['desc'], json['loc'], json['img']);
}

}

class HitsPage {

const HitsPage(this.assets, this.pageKey, this.nextPageKey);

final List<Asset> assets;
final int pageKey;
final int? nextPageKey;

factory HitsPage.fromResponse(SearchResponse response) {
final assets = response.hits.map(Asset.fromJson).toList();
final isLastPage = response.page >= response.nbPages;
final nextPageKey = isLastPage ? null : response.page + 1;
return HitsPage(assets, response.page, nextPageKey);
}

}

class AlgoliaSearchFilters extends StatefulWidget {

const AlgoliaSearchFilters({Key? key, required this.title}) : super(key: key);

final String title;

@override
State<AlgoliaSearchFilters> createState() => _AlgoliaSearchFiltersState();

}

class _AlgoliaSearchFiltersState extends State<AlgoliaSearchFilters> {

final _searchTextController = TextEditingController();

final _assetsSearcher = HitsSearcher(
applicationID: 'OPN6AROJK6',
apiKey: '0ba458475d25b7e2069d700c32e42f29',
indexName: 'asset');

Stream<SearchMetadata> get _searchMetadata =>
_assetsSearcher.responses.map(SearchMetadata.fromResponse);

final PagingController<int, Asset> _pagingController =
PagingController(firstPageKey: 0);

Stream<HitsPage> get _searchPage =>
_assetsSearcher.responses.map(HitsPage.fromResponse);

final GlobalKey<ScaffoldState> _mainScaffoldKey = GlobalKey();

final _filterState = FilterState();

late final _facetList = FacetList(
searcher: _assetsSearcher, filterState: _filterState, attribute: 'loc');

@override
void initState() {
super.initState();

_searchTextController
.addListener(() => _assetsSearcher.query(_searchTextController.text));

_searchPage.listen((page) {
if (page.pageKey == 0) {
_pagingController.refresh();
}
_pagingController.appendPage(page.assets, page.nextPageKey);
}).onError((error) => _pagingController.error = error);

_pagingController.addPageRequestListener((pageKey) =>
_assetsSearcher.applyState((state) => state.copyWith(page: pageKey)));

_assetsSearcher.connectFilterState(_filterState);

_filterState.filters.listen((_) => _pagingController.refresh());
}

@override
Widget build(BuildContext context) {
return Scaffold(
key: _mainScaffoldKey,
appBar: AppBar(
backgroundColor: Colors.blue[900],
title: const Text("Algolia Flutter Search"),
actions: [
IconButton(
onPressed: () => _mainScaffoldKey.currentState?.openEndDrawer(),
icon: const Icon(Icons.filter_list_sharp))
],
),
endDrawer: Drawer(
child: _filters(context),
),
body: Center(
child: Column(
children: <Widget>[
SizedBox(
height: 44,
child: TextField(
controller: _searchTextController,
decoration: const InputDecoration(
border: InputBorder.none,
hintText: 'Enter a search term',
prefixIcon: Icon(Icons.search),
),
)),
StreamBuilder<SearchMetadata>(
stream: _searchMetadata,
builder: (context, snapshot) {
if (!snapshot.hasData) {
return const SizedBox.shrink();
}
return Padding(
padding: const EdgeInsets.all(8.0),
child: Text('${snapshot.data!.nbHits} hits'),
);
},
),
Expanded(
child: _hits(context),
)
],
),
),
);
}

Widget _hits(BuildContext context) => PagedListView<int, Asset>(
pagingController: _pagingController,
builderDelegate: PagedChildBuilderDelegate<Asset>(
noItemsFoundIndicatorBuilder: (_) => const Center(
child: Text('No results found'),
),
itemBuilder: (_, item, __) => Container(
color: Colors.white,
height: 80,
padding: const EdgeInsets.all(8.0),
child: Row(
children: [
SizedBox(width: 50, child: Image.network(item.img)),
const SizedBox(width: 20),
Expanded(child: Text(item.name))
],
),
)));

Widget _filters(BuildContext context) => Scaffold(
appBar: AppBar(
backgroundColor: Colors.blue[900],
title: const Text('Filters'),
),
body: StreamBuilder<List<SelectableItem<Facet>>>(
stream: _facetList.facets,
builder: (context, snapshot) {
if (!snapshot.hasData) {
return const SizedBox.shrink();
}
final selectableFacets = snapshot.data!;
return ListView.builder(
padding: const EdgeInsets.all(8.0),
itemCount: selectableFacets.length,
itemBuilder: (_, index) {
final selectableFacet = selectableFacets[index];
return CheckboxListTile(
value: selectableFacet.isSelected,
title: Text(
'${selectableFacet.item.value} (${selectableFacet.item.count})'),
onChanged: (_) {
_facetList.toggle(selectableFacet.item.value);
},
);
});
}),
);

@override
void dispose() {
_searchTextController.dispose();
_assetsSearcher.dispose();
_pagingController.dispose();
_filterState.dispose();
_facetList.dispose();
super.dispose();
}

}

这些错误只有在我运行程序时才会出现，恳请大家指点可行的修复方案，谢谢！

备注：内容来源于stack exchange，提问作者Vectorr