管理Flutter中的分组列表视图(来自Firestore的数据)

import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';

class GroupedListView extends StatefulWidget {
  @override
  _GroupedListViewState createState() => _GroupedListViewState();
}

class _GroupedListViewState extends State<GroupedListView> {
  List<Group> groups = [];

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

  Future<void> fetchData() async {
    QuerySnapshot snapshot = await FirebaseFirestore.instance
        .collection('your_collection')
        .get();

    List<Group> fetchedGroups = [];

    snapshot.docs.forEach((doc) {
      // Convert document snapshot to model object
      Group group = Group.fromSnapshot(doc);

      // Add group to the list
      fetchedGroups.add(group);
    });

    setState(() {
      groups = fetchedGroups;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Grouped ListView'),
      ),
      body: ListView.builder(
        itemCount: groups.length,
        itemBuilder: (context, index) {
          Group group = groups[index];

          return ExpansionTile(
            title: Text(group.title),
            children: group.items.map((item) {
              return ListTile(
                title: Text(item),
              );
            }).toList(),
          );
        },
      ),
    );
  }
}

class Group {
  final String title;
  final List<String> items;

  Group({required this.title, required this.items});

  factory Group.fromSnapshot(DocumentSnapshot snapshot) {
    Map<String, dynamic> data = snapshot.data() as Map<String, dynamic>;
    List<String> items = List.from(data['items']);

    return Group(
      title: data['title'],
      items: items,
    );
  }
}

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