如何为Flutter应用程序创建Firebase firestore

dependencies:
  firebase_core: ^1.0.0
  cloud_firestore: ^2.0.0

import 'package:firebase_core/firebase_core.dart';

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

import 'package:cloud_firestore/cloud_firestore.dart';

Future<void> getData() async {
  QuerySnapshot snapshot = await FirebaseFirestore.instance.collection('users').get();
  snapshot.docs.forEach((doc) {
    print(doc.data());
  });
}

Future<void> setData() async {
  await FirebaseFirestore.instance.collection('users').doc('user1').set({
    'name': 'John Doe',
    'age': 30,
  });
}

void listenData() {
  FirebaseFirestore.instance.collection('users').snapshots().listen((snapshot) {
    snapshot.docs.forEach((doc) {
      print(doc.data());
    });
  });
}