Flutter与firebase接入

import 'package:firebase_auth/firebase_auth.dart';
final FirebaseAuth _auth = FirebaseAuth.instance;
Future<UserCredential> signInWithEmailAndPassword(String email, String password) async {
  final UserCredential userCredential = await _auth.signInWithEmailAndPassword(
    email: email,
    password: password,
  );
  final User? user = userCredential.user;
  if (user != null && !user.emailVerified) {
    await user.sendEmailVerification();
  }
  return userCredential;
}
Future<void> signOut() async {
  await _auth.signOut();
}

import 'package:firebase_database/firebase_database.dart';
final DatabaseReference _database = FirebaseDatabase.instance.reference();
Future<void> writeData(String path, dynamic data) async {
  await _database.child(path).set(data);
}
Future<dynamic> readData(String path) async {
  final snapshot = await _database.child(path).once();
  return snapshot.value;
}

import 'dart:io';
import 'package:firebase_storage/firebase_storage.dart';
final FirebaseStorage _storage = FirebaseStorage.instance;
Future<String> uploadFile(File file, String path) async {
  final reference = _storage.ref().child(path);
  final uploadTask = reference.putFile(file);
  final snapshot = await uploadTask.whenComplete(() {});
  final url = await snapshot.ref.getDownloadURL();
  return url;
}
Future<File> downloadFile(String url, String path) async {
  final reference = _storage.refFromURL(url);
  final downloadTask = reference.writeToFile(File(path));
  await downloadTask.future;
  return File(path);
}