flutter firebase 登录问题

Question

我最近在我的应用程序上使用 login/register 模块进行了一些工作，但有 2 个东西不工作：

首先，当我注册时没问题，我可以在我的 Firebase 控制台中看到该应用程序正在创建一个新用户，所以这很好。但是，当我尝试使用不存在的用户登录时，它仍然让我转到主页。
不知道如何进行持久登录，比如有人登录，有人在关闭应用程序时注册，然后重新启动应用程序，他们应该能够保持登录状态，然后在需要时注销。

有人能帮忙吗？？

我把代码留在这里：

主要

import 'package:flutter/material.dart';
import 'package:sport_app/auth_screen.dart';
import 'package:sport_app/home_screen.dart';
import 'package:sport_app/intro_screen.dart';


void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
        inputDecorationTheme: InputDecorationTheme(
          filled: true,
          fillColor: Color(0xfff2f9fe),
          enabledBorder: OutlineInputBorder(
            borderSide: BorderSide(color: Colors.grey[200]),
            borderRadius: BorderRadius.circular(25),
          ),
          focusedBorder: OutlineInputBorder(
            borderSide: BorderSide(color: Colors.grey[200]),
            borderRadius: BorderRadius.circular(25),
          ),
          disabledBorder: OutlineInputBorder(
            borderSide: BorderSide(color: Colors.grey[200]),
            borderRadius: BorderRadius.circular(25),
          ),
        ),
      ),
      home: IntroScreen(),
      routes: {
        'intro': (context) => IntroScreen(),
        'home': (context) => HomeScreen(),
        'login': (context) => AuthScreen(authType: AuthType.login),
        'register': (context) => AuthScreen(authType: AuthType.register),
      },
    );
  }
}

AUTH_PAGE

import 'package:flutter/material.dart';
import 'package:sport_app/auth_screen.dart';
import 'package:sport_app/auth.dart';
import 'package:sport_app/original_button.dart';


class AuthForm extends StatefulWidget {
  final AuthType authType;

  const AuthForm({Key key, @required this.authType}) : super(key: key);

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

class _AuthFormState extends State<AuthForm> {
  final _formKey = GlobalKey<FormState>();
  String _email = '', _password = '';
  AuthBase authBase = AuthBase();

  @override
  Widget build(BuildContext context) {
    return Form(
      key: _formKey,
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 50, vertical: 20),
        child: Column(
          children: <Widget>[
            TextFormField(
              decoration: InputDecoration(
                labelText: 'Enter your email',
                hintText: 'ex: test@gmail.com',
              ),
              onChanged: (value) {
                _email = value;
              },
              validator: (value) =>
              value.isEmpty ? 'You must enter a valid email' : null,
            ),
            SizedBox(height: 10),
            TextFormField(
              decoration: InputDecoration(
                labelText: 'Enter your password',
              ),
              obscureText: true,
              onChanged: (value) {
                _password = value;
              },
              validator: (value) => value.length <= 6
                  ? 'Your password must be larger than 6 characters'
                  : null,
            ),
            SizedBox(height: 20),
            OriginalButton(
              text: widget.authType == AuthType.login ? 'Login' : 'Register',
              color: Colors.lightBlue,
              textColor: Colors.white,
              onPressed: () async {
                if (_formKey.currentState.validate()) {
                  if (widget.authType == AuthType.login) {
                    await authBase.loginWithEmailAndPassword(_email, _password);
                    Navigator.of(context).pushReplacementNamed('home');
                  } else {
                    await authBase.registerWithEmailAndPassword(_email, _password);
                    Navigator.of(context).pushReplacementNamed('home');
                  }
//                  print(_email);
//                  print(_password);
                }
              },
            ),
            SizedBox(height: 6),
            FlatButton(
              onPressed: () {
                if (widget.authType == AuthType.login) {
                  Navigator.of(context).pushReplacementNamed('register');
                  print(widget.authType);
                } else {
                  Navigator.of(context).pushReplacementNamed('login');
                }
              },
              child: Text(
                widget.authType == AuthType.login
                    ? 'Don\'t have an account?'
                    : 'Already have an account?',
                style: TextStyle(fontSize: 18, color: Colors.black54),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

AUTHBASE

import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';

class User {
  final String uid;

  User({@required this.uid});
}

class AuthBase {
  User _userFromFirebase(FirebaseUser user) {
    return user != null ? User(uid: user.uid) : null;
  }

  Future<void> registerWithEmailAndPassword(
      String email, String password) async {
    try {
      final authResult = await FirebaseAuth.instance
          .createUserWithEmailAndPassword(email: email, password: password);
      return _userFromFirebase(authResult.user);
    } catch (e) {
      print(e.toString());
      return null;
    }
  }

  Future<void> loginWithEmailAndPassword(String email, String password) async {
    try {
      final authResult = await FirebaseAuth.instance
          .signInWithEmailAndPassword(email: email, password: password);
      return _userFromFirebase(authResult.user);
    } catch (e) {
      print(e.toString());
      return null;
    }
  }

  Future<void> logout() async {
    await FirebaseAuth.instance.signOut();
  }
}

Answer 1

更新

您只需导航至主页，即使登录未成功完成，因为没有条件逻辑。仅在您的 authBase class 中进行导航，那么您应该没问题。

您需要导入 FirebaseAuthException 才能使用它。那么，你

Future<bool> loginWithEmailAndPassword(String email, String password) async {
    try {
      final authResult = await FirebaseAuth.instance
          .signInWithEmailAndPassword(email: email, password: password);
      if(authResult.user != null) { Navigator.of(context).pushReplacementNamed('home'); }
    } on FirebaseAuthException catch (e) {
      print(e.toString());
      if(e.code == 'wrong-password') { Scaffold.of(context).showSnackBar(SnackBar(
      content: Text("Wrong Password"),
    )); } 
      else if (e.code == 'user-not-found') { Scaffold.of(context).showSnackBar(SnackBar(
      content: Text("User not found"),
    )); }
      else if (e.code == 'invalid-email') { Scaffold.of(context).showSnackBar(SnackBar(
      content: Text("Invalid E-Mail"),
    )); }
      return false;
    }
  }

并删除将您的小部件代码更改为：

if (_formKey.currentState.validate()) {
  if (widget.authType == AuthType.login) {
    await authBase.loginWithEmailAndPassword(_email, _password);
  } else {
    await authBase.registerWithEmailAndPassword(_email, _password);
  }
}

第二个问题：您可以尝试在第一次登录后将登录凭据存储在存储（用户flutter_secure_storage 加密包）中，然后在应用程序启动时检索它以执行上述登录

这是一个 link 用于存储凭据的包

flutter_secure_storage

flutter firebase 登录问题

issue with flutter firebase login

firebase

flutter

firebase-authentication

persistent

更新