Why my Flutter JSON data didn't updated from setState?

I've made the JSON data and appear it into FutureBuilder with ListView.builder widget. I want to create a favorite Icon in the trailing of the ListView.builder. So i created it with IconButton, but when I create setState to make some item as favorited, the data didn't updated.

Here is my code

import 'package:flutter/material.dart';  import 'package:json_test/class/doa.dart';  import 'package:json_test/page/DoaPage.dart';    class MainPage extends StatefulWidget {    @override    _MainPageState createState() => _MainPageState();  }    class _MainPageState extends State<MainPage> {    Future<List<Doa>> fetchDoa(BuildContext context) async {      final jsonstring =          await DefaultAssetBundle.of(context).loadString('assets/doa.json');      return doaFromJson(jsonstring);    }      @override    Widget build(BuildContext context) {      return Scaffold(          appBar: AppBar(            title: Text("JSON Data test"),          ),          body: Container(              child: FutureBuilder(                  future: fetchDoa(context),                  builder: (context, snapshot) {                    if (snapshot.hasData) {                      return ListView.builder(                        itemCount: snapshot.data.length,                        itemBuilder: (BuildContext context, int index) {                          Doa doa = snapshot.data[index];                          return Card(                              margin: EdgeInsets.all(8),                              child: ListTile(                                  title: Text(doa.judul),                                  onTap: () {                                    Navigator.of(context).push(MaterialPageRoute(                                        builder: (BuildContext context) =>                                            DoaPage(                                              doa: doa,                                            )));                                  },                                  trailing: IconButton(                                    icon: Icon(                                      doa.fav                                          ? Icons.favorite                                          : Icons.favorite_border,                                      color: doa.fav ? Colors.red : null,                                    ),                                    onPressed: () =>                                        setState(() => doa.fav = !doa.fav),                                  )));                        },                      );                    }                    return CircularProgressIndicator();                  })));    }  }  

and this is the preview

https://stackoverflow.com/questions/67040738/why-my-flutter-json-data-didnt-updated-from-setstate April 11, 2021 at 09:38AM