显示来自firestore的N个uid我是flutter新手

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 usersCollection = FirebaseFirestore.instance.collection('users');

Future<List<String>> getUIDs(int n) async {
  QuerySnapshot querySnapshot = await usersCollection.limit(n).get();
  List<String> uids = [];
  querySnapshot.docs.forEach((doc) {
    uids.add(doc.id);
  });
  return uids;
}

// 在Flutter界面上展示N个uid
Widget buildUIDList() {
  return FutureBuilder<List<String>>(
    future: getUIDs(N),
    builder: (context, snapshot) {
      if (snapshot.connectionState == ConnectionState.waiting) {
        return CircularProgressIndicator();
      } else if (snapshot.hasError) {
        return Text('Error: ${snapshot.error}');
      } else {
        List<String> uids = snapshot.data;
        return ListView.builder(
          itemCount: uids.length,
          itemBuilder: (context, index) {
            return ListTile(
              title: Text(uids[index]),
            );
          },
        );
      }
    },
  );
}