从firestore获取集合，.map不工作(flutter)

import 'package:firebase_core/firebase_core.dart';
import 'package:cloud_firestore/cloud_firestore.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MyApp());
}

CollectionReference collectionRef = FirebaseFirestore.instance.collection('your_collection_name');
Stream<QuerySnapshot> snapshots = collectionRef.snapshots();

StreamBuilder<QuerySnapshot>(
  stream: snapshots,
  builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
    if (snapshot.hasError) {
      return Text('Error: ${snapshot.error}');
    }

    if (snapshot.connectionState == ConnectionState.waiting) {
      return Text('Loading...');
    }

    return ListView(
      children: snapshot.data.docs.map((DocumentSnapshot document) {
        // 在这里处理每个文档的数据
        return ListTile(
          title: Text(document.data()['title']),
          subtitle: Text(document.data()['description']),
        );
      }).toList(),
    );
  },
);