"Flutter Riverpod 不调用函数"

Question

I'm starting with Flutter and I chose Riverpod to manage my state. I created a StateNotifier that has two functions, one setSelected that chooses the item in the menu and the other getSelected that checks who was selected and changes the colors. The first works on click but the second only works when starting the page.

Below are my classes:

1- MenuNotifier

class MenuNotifier extends StateNotifier<CategoryModel> {
  MenuNotifier() : super(menuItem);

  static CategoryModel menuItem = CategoryModel.allCategories.first;

  void setSelected(CategoryModel item) {
    menuItem = item;
    print(menuItem.id);
  }

  bool getSelected(CategoryModel item) {
    return menuItem.id == item.id ? true : false;
  }
}

2 - MenuCategoryComponent

final menuProvider = StateNotifierProvider<MenuNotifier, CategoryModel>((ref) {
  return MenuNotifier();
});

class MenuCategoryComponent extends ConsumerWidget {
  List<CategoryModel> allCategories = CategoryModel.allCategories;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    return Container(
      color: uiColor.second,
      child: ListView.builder(
          itemCount: allCategories.length,
          scrollDirection: Axis.horizontal,
          itemBuilder: (BuildContext context, int index) {
            return Consumer(builder: (context, ref, _) {
              final _menuItem = ref.watch(menuProvider.notifier);
              return Container(
                color: ref
                        .read(menuProvider.notifier)
                        .getSelected(allCategories[index])
                    ? uiColor.comp_1
                    : uiColor.second,
                child: TextButton(
                  style: TextButton.styleFrom(
                    padding: EdgeInsets.zero,
                    alignment: Alignment.center,
                    shape: RoundedRectangleBorder(
                      borderRadius: BorderRadius.circular(20),
                    ),
                  ),
                  child: Padding(
                    padding: const EdgeInsets.all(10),
                    child: Text(allCategories[index].label!,
                        style: uiTextStyle.text1),
                  ),
                  onPressed: () {
                    ref
                        .read(menuProvider.notifier)
                        .setSelected(allCategories[index]);
                  },
                ),
              );
            });
          }),
    );
  }
}

As you can see I have a Container that should change color with a condition that returns a boolean if the selected item is the same as the current one in the ListView. And I use read from Riverpod.

Answer 1

I think the problem is you are watching the .notifier<\/code> instead of listening to its changes, by the docs: