StateNotifierProvider：是否可以使用单个 StateNotifierProvider

问题描述

class SearchFilterModel {
  bool searchBydistance;
  bool filterByStatusOpen;
  String searchText;

  ...
}

class SearchFilterModelNotifier extends StateNotifier<SearchFilterModel> {
  SearchFilterModelNotifier() 
    : super(SearchFilterModel(
        searchBydistance: true,filterByStatusOpen: false,searchText: ''));

  void updateSearchBydistance(bool searchBydistance) {
    state.searchBydistance = searchBydistance;
  }

  void updatefilterByStatusOpen(bool filterByStatusOpen) {
    state.filterByStatusOpen = filterByStatusOpen;
  }

  void updateSearchText(String searchText) {
    state.searchText = searchText;
  }
}

final searchFilterModelNotifierProvider = StateNotifierProvider<SearchFilterModelNotifier,SearchFilterModel>((ref) => SearchFilterModelNotifier());

class SearchForm extends ConsumerWidget {
  @override
  Widget build(context,watch) {
    final searchFilterModelNotifier = watch(searchFilterModelNotifierProvider.notifier);
    final searchFilterModel = watch(searchFilterModelNotifierProvider);

    return Form(
      child: Column(
        children: [
          SwitchListTile(
            value: searchFilterModel.searchBydistance,onChanged: (bool value) => searchFilterModelNotifier.updateSearchBydistance(value),title: Text('Search by distance?')),SwitchListTile(
            value: searchFilterModel.filterByStatusOpen,onChanged: (bool value) => searchFilterModelNotifier.updatefilterByStatusOpen(value),title: Text('Filter by open status?')),// not even sure how to do the text one if using a TextFormField
          ]
        )
      );
    }
}

好的，我的项目结构如此，开关的值没有按预期运行，它们的值根本没有更新，我相信只是小部件没有重建。我能够为每个表单字段使用不同的状态提供程序来完成这项工作，但是当我有很多表单字段时，能够拥有一个代表整个表单的单个 StateNotifierProvider 会更好。这是不可能的事情吗？

解决方法

答案是将 StateNotifier 方法更新为类似

void updateSearchByDistance(bool searchByDistance) {
  state = SearchFilterModel(... searchByDistance: searchByDistance);
}