持久用户身份验证 Flutter Firebase

问题描述

我使用 Firebase Auth 和 Google 登录 Flutter.我可以登录，但是当我关闭应用程序(杀死它)时，我必须重新注册.那么有没有一种方法可以将用户身份验证持久化，直到用户专门注销?这是我的身份验证课程

import 'package:firebase_auth/firebase_auth.dart';导入包:google_sign_in/google_sign_in.dart"；类认证{FirebaseAuth _firebaseAuth;FirebaseUser _user;认证(){this._firebaseAuth = FirebaseAuth.instance;}未来isLoggedIn() 异步 {this._user = await _firebaseAuth.currentUser();如果(this._user == null){返回假；}返回真；}未来authenticationWithGoogle() 异步 {最终 googleSignIn = GoogleSignIn();最终 GoogleSignInAccount googleUser = 等待 googleSignIn.signIn();最终的 GoogleSignInAuthentication googleAuth =等待 googleUser.authentication;this._user = await _firebaseAuth.signInWithGoogle(accessToken: googleAuth.accessToken,idToken: googleAuth.idToken,);如果(this._user == null){返回假；}返回真；//对登录用户做一些事情}}

这是调用身份验证检查的起始页.

import 'package:flutter/material.dart';导入 'auth.dart';导入 'login_screen.dart';导入 'chat_screen.dart';类 Splash 扩展了 StatefulWidget {@覆盖_Splash createState() =>_溅();}class _Splash 扩展 State{@覆盖小部件构建(BuildContext 上下文){返回脚手架(身体:中心(孩子:CircularProgressIndicator(值:空，),),);}@覆盖无效的初始化状态(){super.initState();_handleStartScreen();}未来<void>_handleStartScreen() 异步 {Auth _auth = Auth();如果(等待_auth.isLoggedIn()){Navigator.of(context).pushReplacementNamed("/chat");}Navigator.pushReplacement(context, MaterialPageRoute(builder: (BuildContext context) => LoginScreen(auth: _auth,)));}}

解决方案

我相信您的问题是路由.在我的应用程序中，我使用 FirebaseAuth 并且它按照您说的那样工作，并且我不保留任何登录令牌.但是，我不知道为什么您使用 getUser 的方法不起作用.

尝试调整您的代码以使用 onAuthStateChanged.

基本上，在您的 MaterialApp 上，创建一个 StreamBuilder 监听 _auth.onAuthStateChanged 并根据 Auth 状态选择您的页面.>

我将复制并粘贴我的应用程序的部分内容，以便您有一个想法:

[...]最终 FirebaseAuth _auth = FirebaseAuth.instance;未来<void>主()异步{FirebaseApp.configure(名称: '...'，选项:平台.isIOS?const FirebaseOptions(...): const FirebaseOptions(...),);[...]运行应用程序(新材料应用程序(标题: '...'，主页:等待 getLandingPage()，主题:ThemeData(...),));}未来getLandingPage() 异步 {返回 StreamBuilder(流:_auth.onAuthStateChanged，构建器:(BuildContext 上下文，快照){如果 (snapshot.hasData && (!snapshot.data.isAnonymous)) {返回主页()；}返回 AccountLoginPage();},);}

I am using Firebase Auth with google sign in Flutter. I am able to sign in however when I close the app(kill it), I have to sign up all over again. So is there a way to persist user authentication till specifically logged out by the user?Here is my auth class

import 'package:firebase_auth/firebase_auth.dart';
import 'package:google_sign_in/google_sign_in.dart';

class Auth {
  FirebaseAuth _firebaseAuth;
  FirebaseUser _user;

  Auth() {
    this._firebaseAuth = FirebaseAuth.instance;
  }

  Future<bool> isLoggedIn() async {
    this._user = await _firebaseAuth.currentUser();
    if (this._user == null) {
      return false;
    }
    return true;
  }

  Future<bool> authenticateWithGoogle() async {
    final googleSignIn = GoogleSignIn();
    final GoogleSignInAccount googleUser = await googleSignIn.signIn();
    final GoogleSignInAuthentication googleAuth =
    await googleUser.authentication;
    this._user = await _firebaseAuth.signInWithGoogle(
      accessToken: googleAuth.accessToken,
      idToken: googleAuth.idToken,
    );
    if (this._user == null) {
      return false;
    }
    return true;
    // do something with signed-in user
  }
}

Here is my start page where the auth check is called.

import 'package:flutter/material.dart';
import 'auth.dart';
import 'login_screen.dart';
import 'chat_screen.dart';

class Splash extends StatefulWidget {

  @override
  _Splash createState() => _Splash();
}

class _Splash extends State<Splash> {

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: CircularProgressIndicator(
          value: null,
        ),
      ),
    );
  }

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

  Future<void> _handleStartScreen() async {
    Auth _auth = Auth();
    if (await _auth.isLoggedIn()) {
      Navigator.of(context).pushReplacementNamed("/chat");
    }
    Navigator.pushReplacement(context, MaterialPageRoute(builder: (BuildContext context) => LoginScreen(auth: _auth,)));
  }
}

解决方案

I believe your problem is routing. In my apps I use FirebaseAuth and it works just as you say you wanted to, and I don't persist any login token. However, I don't know why your approach of using a getUser is not working.

Try to adjust your code to use onAuthStateChanged.

Basically, on your MaterialApp, create a StreamBuilder listening to _auth.onAuthStateChanged and choose your page depending on the Auth status.

I'll copy and paste parts of my app so you can have an idea:

[...]

final FirebaseAuth _auth = FirebaseAuth.instance;

Future<void> main() async {
  FirebaseApp.configure(
    name: '...',
    options:
      Platform.isIOS
        ? const FirebaseOptions(...)
        : const FirebaseOptions(...),
    );

  [...]

  runApp(new MaterialApp(
    title: '...',
    home: await getLandingPage(),
    theme: ThemeData(...),
  ));
}

Future<Widget> getLandingPage() async {
  return StreamBuilder<FirebaseUser>(
    stream: _auth.onAuthStateChanged,
    builder: (BuildContext context, snapshot) {
      if (snapshot.hasData && (!snapshot.data.isAnonymous)) {
        return HomePage();
      }

      return AccountLoginPage();
    },
  );
}

这篇关于持久用户身份验证 Flutter Firebase的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！