Stuck with json in flutter - json

Question

I dont know the problem is because when debuging there isn't error info but the value of json is empty when I print info.lenght
class _HomePageState extends State<HomePage> {
List info = [];
_initData(){
DefaultAssetBundle.of(context).loadString("json/info.json").then((value){
info = jsonDecode(value);
});
}
#override
void iniState(){
super.initState();
_initData();
}
and below is my json code in json/info.json
[
{
"title": "Glue",
"img": "assets/ex1.png"
},
{
"title": "Abs",
"img": "assets/ex2.png"
},
{
"title": "Legs",
"img": "assets/ex3.png"
},
{
"title": "Arms",
"img": "assets/ex4.png"
}
]
and how to we print the img and title value of json in dart?

Answer 1

You have to first create a model class for your json response.
// To parse this JSON data, do
//
// final jsonModel = jsonModelFromJson(jsonString);
import 'dart:convert';
List<JsonModel> jsonModelFromJson(String str) => List<JsonModel>.from(json.decode(str).map((x) => JsonModel.fromJson(x)));
String jsonModelToJson(List<JsonModel> data) => json.encode(List<dynamic>.from(data.map((x) => x.toJson())));
class JsonModel {
JsonModel({
this.title,
this.img,
});
String title;
String img;
factory JsonModel.fromJson(Map<String, dynamic> json) => JsonModel(
title: json["title"] == null ? null : json["title"],
img: json["img"] == null ? null : json["img"],
);
Map<String, dynamic> toJson() => {
"title": title == null ? null : title,
"img": img == null ? null : img,
};
}
then just use this model class to decode your json file.
var result = JsonModel.fromJson(jsonResponse);
Later, you can just use
result.title or result.img to get the data

Answer 2

You have to add your json file into pubspec.yaml file.
flutter:
assets:
- json/info.json
Before loading page view, you should load values from your json file and assign a list in initState. After that, you can use list as map by [index][header].
class JsonResult extends StatefulWidget {
const JsonResult({Key? key}) : super(key: key);
#override
_JsonResultState createState() => _JsonResultState();
}
class _JsonResultState extends State<JsonResult> {
var jsonList = [];
#override
void initState() {
rootBundle.loadString("json/info.json").then((value) {
jsonList = json.decode(value);
});
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: ListView.builder(
itemBuilder: (context, index) {
return ListTile(
leading: Image.asset(jsonList[index]["img"]),
title: Text(jsonList[index]["title"]),
);
},
itemCount: jsonList.length,
),
),
);
}
}