Flutter 使用共享首选项按 id 保存数据

Question

I have a listView, in which I have some products. I wanted a rating system on each product details page so I go through this answer How to save User rating in flutter rating bar?. Now the problem is that I am getting my star rating the same on each product detail page. Now please suggest to me, to save the value of the star with respect to product id in my shared preferences.

Or anyone has another solution please share it with me.

Rating Controller

class RatingController extends GetxController {
  int currentRating = 0;
  final box = GetStorage();

  late SharedPreferences prefs;

  @override
  void onInit() { // called whenever we initialize the controller
    super.onInit();
    currentRating = box.read('rating') ?? 0; // initializing current rating from storage or 0 if storage is null
  }

  void updateAndStoreRating(int rating) {
    currentRating = rating;
    prefs.setInt('rating', rating); //SharedPreferences way
    update(); // triggers a rebuild of the GetBuilder Widget
  }
  Future<void> initSp() async {
    prefs = await SharedPreferences.getInstance();
    currentRating = prefs.getInt('rating') ?? 0;
  }

  Widget buildRatingStar(int index) {
    if (index < currentRating) {
      return Icon(
        Icons.star,
        color: Colors.yellow,
      );
    } else {
      return Icon(
        Icons.star,
        color: Colors.white,
      );
    }
  }
}

Rating Widget

SharedPreferences? _prefs;
 

  final controller = Get.find<RatingController>();

  Widget _buildBody() {
    final stars = List<Widget>.generate(5, (index) {
      return GetBuilder<RatingController>( // rebuilds when update() is called from GetX class
        builder: (controller) => Expanded(
          child: GestureDetector(
            child: controller.buildRatingStar(index),
            onTap: () {
              controller.updateAndStoreRating(index + 1);
              print(index + 1);// +1 because index starts at 0 otherwise the star rating is offset by one
            },
          ),
        ),
      );
    });
    return Row(
      children: [
        Expanded(
          child: Row(
            children: stars,
          ),
        ),
        Expanded(
          child: TextButton(
            onPressed: () {
              controller.updateAndStoreRating(0);
            },
            child: Text(
              "Clear",
              style: TextStyle(color: Colors.white),
            ),
          ),
        ),
      ],
    );
  }

This working and saving star values but I am getting this value in all my list data's detail page. so please suggest me to save using particular index.

Answer 1

GetStorage cant save Map based data type and in your case it's better to use Hive :

First, add hive to your dependencies:

  hive: ^2.0.4
  hive_flutter: ^1.1.0

Then initialize it at the beginning of the application:

await Hive.initFlutter();

And use it like this:

var box = await Hive.openBox('myBox');
var person = Person()
  ..name = 'Dave'
  ..age = 22;
box.add(person);
print(box.getAt(0)); // Dave - 22
person.age = 30;
person.save();
print(box.getAt(0)) // Dave - 30

You can see more examples about using hive in this link .