expected a value of type 'int' but got one of type 'string' flutter-CodePudding

I am trying to fetch data from realtime database using http mathod "GET". The data is being retreived but it's not showing up in listview and when i print the length of my list it's 0. And this is what the error is being shown in my terminal: Error: Expected a value of type 'int', but got one of type 'String'

I can't figure out what the problem is. Please help me solve this problem because i am trying for around 5 days but can't solve it.

Thank you.

These are my codes for fetching the data in lists.

   import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;

void main() => runApp(myapp());

class myapp extends StatelessWidget {
  const myapp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Home(),
    );
  }
}

/*Future<List> getData() async {
  final response =
      await http.get(Uri.https('dontworry.in', 'app/viewuser.php'));
  var datareceived = jsonDecode(response.body);
  //print(datareceived);
  return datareceived;
}*/

class Home extends StatefulWidget {
  const Home({Key? key}) : super(key: key);

  @override
  _HomeState createState() => _HomeState();
}

class _HomeState extends State<Home> {
  Future<List> getData() async {
    //final response = await http.get(Uri.https('dontworry.in', 'app/viewuser.php'));
    final response =
        await http.get(Uri.parse('https://dontworry.in/app/viewuser.php'));
    var datareceived = jsonDecode(response.body);
    print(datareceived);
    return datareceived;
  }

  @override
  void initState() {
    getData();
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Flutter Database"),
      ),
      body: FutureBuilder(
        future: getData(),
        builder: (context, snapshot) {
          if (snapshot.hasError) {
            print('Error in loading'   snapshot.hasError.toString());
          }
          return snapshot.hasData
              ? new Itemlist(
                  list: [snapshot.data],
                )
              : const Center(
                  child: CircularProgressIndicator(),
                );
        },
      ),
    );
  }
}

class Itemlist extends StatelessWidget {
  final List list;
  const Itemlist({Key? key, required this.list}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return ListView.builder(
        itemCount: list == null ? 0 : list.length,
        itemBuilder: (context, i) {
          return Card(
            child: ListTile(
              title: new Text(list[i]['NAME']),
            ),
          );
        });
  }
}

My PHP Code json encode is

<?php
include "config.php";

$sql= "SELECT * FROM contacts ORDER BY NAME";
$result= array();
$res=$con->query($sql);

if($res->num_rows>0){
    while($row=$res->fetch_assoc()){
        $result[]=$row;
    }
}

echo json_encode($result);

    ?>

Please help me

CodePudding user response：

If you want a quick fix, and you are sure that the value is an int but in a string format, then you can use tryParse method

print(int.tryParse('2021')); // 2021
print(int.tryParse('1f')); // null

CodePudding user response：

I ran your code, your only issue is that you were wrapping your list into another list. Your code is this:

new Itemlist(list: [snapshot.data])

This means you are adding snapshot.data which is already a list, and you are adding it inside another list (by adding it inside brackets), so just do it like this:

new Itemlist(list: snapshot.data as List)

I see now your data coming through:

Suggestion:

Try creating a separate class that maps your data into a strongly typed model after fetching the JSON data, like in here https://docs.flutter.dev/cookbook/networking/fetch-data#create-an-album-class