如何在flutter中获取列表中所需的数据？

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

class Item {
  final int id;
  final String name;
  
  Item({required this.id, required this.name});
  
  factory Item.fromJson(Map<String, dynamic> json) {
    return Item(
      id: json['id'],
      name: json['name'],
    );
  }
}

class MyListScreen extends StatefulWidget {
  @override
  _MyListScreenState createState() => _MyListScreenState();
}

class _MyListScreenState extends State<MyListScreen> {
  List<Item> itemList = [];
  bool isLoading = true;

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

  Future<void> fetchData() async {
    try {
      var response = await http.get(Uri.parse('https://example.com/api/items'));
      if (response.statusCode == 200) {
        var data = json.decode(response.body);
        List<Item> items = [];
        for (var item in data) {
          items.add(Item.fromJson(item));
        }
        setState(() {
          itemList = items;
          isLoading = false;
        });
      } else {
        throw Exception('Failed to fetch data');
      }
    } catch (error) {
      setState(() {
        isLoading = false;
      });
      showDialog(
        context: context,
        builder: (BuildContext context) {
          return AlertDialog(
            title: Text('Error'),
            content: Text('Failed to fetch data. Please try again later.'),
            actions: [
              TextButton(
                child: Text('OK'),
                onPressed: () {
                  Navigator.of(context).pop();
                },
              ),
            ],
          );
        },
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('My List'),
      ),
      body: isLoading
          ? Center(
              child: CircularProgressIndicator(),
            )
          : ListView.builder(
              itemCount: itemList.length,
              itemBuilder: (BuildContext context, int index) {
                return ListTile(
                  title: Text(itemList[index].name),
                  subtitle: Text('ID: ${itemList[index].id}'),
                );
              },
            ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: MyListScreen(),
  ));
}