安卓——我添加了一个底部栏，但当我登录时，该栏消失了

所以我正在构建一个有登录名的应用程序（我知道我会飞，所以我只是在youtube上获取代码并尝试添加它），它应该有一个底部栏，利兹可以删除主页和个人资料屏幕。在个人资料屏幕中，他可以注销。

问题是，应用程序都很好，但我试图添加底部栏（我必须添加一个AuthWrapper（）

import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';
import 'package:pap_test/tabs_screen.dart';
import 'login_signup/screens/login_screen.dart';

class AuthWrapper extends StatelessWidget {
  const AuthWrapper({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final FirebaseAuth _auth = FirebaseAuth.instance;
    return StreamBuilder(
      stream: _auth.authStateChanges(),
      builder: (context, user) {
        User? _user = user.data as User?;
        if (_user != null) {
          return const TabsScreen();
        } else {
          return const LoginScreen();
        }
      },
    );
  }
}

进入主页和个人资料页面。

// ignore_for_file: prefer_const_constructors, prefer_const_literals_to_create_immutables

import 'package:flutter/material.dart';
import 'disciplinas/disciplinas_screen.dart';
import 'login_signup/screens/home_screen.dart';

class TabsScreen extends StatefulWidget {
  const TabsScreen({Key? key}) : super(key: key);

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

class _TabsScreenState extends State {
  final List _pages = [
    DisciplinasScreen(),
    HomeScreen(),
  ];

  int _selectedPageIndex = 0;

  void _selectPage(int index) {
    setState(() {
      _selectedPageIndex = index;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
          '',
        ), //seja qual for a opção do bottom bar selecionada ele irá dar o titulo que indicamos e mesmo para a outra página
      ),
      body: _pages[_selectedPageIndex],
      bottomNavigationBar: BottomNavigationBar(
        onTap: _selectPage,
        backgroundColor: Colors.black,
        items: [
          BottomNavigationBarItem(
            icon: Icon(Icons.home),
            label: 'Home',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.account_circle_outlined),
            label: 'Profile',
          ),
        ],
      ),
    );
  }
}

问题是，当我在应用程序中，当我重建它时，底部栏在那里，但应用程序栏变得很奇怪，当我进入配置文件屏幕时，注销然后登录，应用程序栏恢复正常，但底部栏不在那里。

主要是死记硬背

routes: {
        '/': (ctx) => AuthWrapper(),
        DisciplinaModuloScreen.routeName: (ctx) => DisciplinaModuloScreen(),
        DownloadScreen.routeName: (ctx) => DownloadScreen(),
        UploadResumoScreen.routeName: (ctx) => UploadResumoScreen(),
      },

登录

import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';
import 'package:fluttertoast/fluttertoast.dart';
import '../../disciplinas/disciplinas_screen.dart';
import '../screens/registration_screen.dart';

class LoginScreen extends StatefulWidget {
  const LoginScreen({Key? key}) : super(key: key);

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

class _LoginScreenState extends State {
  //form key
  final _formKey = GlobalKey();

  //editing controller
  final TextEditingController emailController = new TextEditingController();
  final TextEditingController passwordController = new TextEditingController();

  // firebase
  final _auth = FirebaseAuth.instance;

  // string for displaying the error Message
  String? errorMessage;

  @override
  Widget build(BuildContext context) {
    // email field
    final emailField = TextFormField(
      style: Theme.of(context).textTheme.headline6,
      autofocus: false,
      controller: emailController,
      keyboardType: TextInputType.emailAddress,
      validator: (value) {
        if (value!.isEmpty) {
          return ('Email obrigatório');
        }
        // reg expression for email validation
        if (!RegExp("^[a-zA-Z0-9+_.-]+@[a-zA-Z0-9.-]+.[a-z]").hasMatch(value)) {
          return ('Insira um email válifo');
        }
        return null;
      },
      onSaved: (value) {
        emailController.text = value!;
      },
      textInputAction: TextInputAction.next,
      decoration: InputDecoration(
        prefixIcon: Icon(
          Icons.mail,
          color: Color.fromARGB(255, 28, 209, 216),
        ),
        contentPadding: EdgeInsets.fromLTRB(20, 15, 20, 15),
        hintText: 'Email',
        hintStyle: Theme.of(context).textTheme.headline2,
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(15),
          //borderSide: BorderSide(color: Colors.pink, width: 5.0),
        ),
      ),
    );

    // password field
    final passwordField = TextFormField(
      style: Theme.of(context).textTheme.headline6,
      autofocus: false,
      controller: passwordController,
      obscureText: true,
      validator: (value) {
        RegExp regex = new RegExp(r'^.{6,}$');
        if (value!.isEmpty) {
          return ('Insira uma password');
        }
        if (!regex.hasMatch(value)) {
          return ('Utilize 6 ou mais carateres');
        }
      },
      onSaved: (value) {
        passwordController.text = value!;
      },
      textInputAction: TextInputAction.done,
      decoration: InputDecoration(
        prefixIcon: Icon(
          Icons.vpn_key,
          color: Color.fromARGB(255, 28, 209, 216),
        ),
        contentPadding: EdgeInsets.fromLTRB(20, 15, 20, 15),
        hintText: 'Password',
        hintStyle: Theme.of(context).textTheme.headline2,
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(15),
          borderSide: BorderSide(color: Colors.pink, width: 5.0),
        ),
      ),
    );

    // login field
    final loginButton = Material(
      elevation: 5,
      borderRadius: BorderRadius.circular(15),
      color: Color.fromARGB(255, 28, 209, 216),
      child: MaterialButton(
        padding: EdgeInsets.fromLTRB(20, 15, 20, 15),
        minWidth: MediaQuery.of(context).size.width,
        onPressed: () {
          signIn(emailController.text, passwordController.text);
        },
        child: Text(
          'Login',
          textAlign: TextAlign.center,
          style: Theme.of(context).textTheme.headline6,
        ),
      ),
    );

    return Scaffold(
      // backgroundColor: ,
      body: Center(
        child: SingleChildScrollView(
          child: Container(
            // color: Colors.white,
            child: Padding(
              padding: const EdgeInsets.all(36.0),
              child: Form(
                key: _formKey,
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: [
                    SizedBox(
                      height: 200,
                      child: Image.asset(
                        'assets/images/owl_white.png',
                        fit: BoxFit.contain,
                      ),
                    ),
                    emailField,
                    SizedBox(height: 15),
                    passwordField,
                    SizedBox(height: 30),
                    loginButton,
                    SizedBox(height: 15),
                    Row(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        Text(
                          'Não tens conta? ',
                          style: Theme.of(context).textTheme.bodyText1,
                        ),
                        GestureDetector(
                          onTap: () {
                            Navigator.push(
                              context,
                              MaterialPageRoute(
                                builder: (context) => RegistrationScreen(),
                              ),
                            );
                          },
                          child: Text(
                            'SignUp',
                            style: Theme.of(context).textTheme.bodyText2,
                          ),
                        )
                      ],
                    )
                  ],
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }

  void signIn(String email, String password) async {
    if (_formKey.currentState!.validate()) {
      try {
        await _auth
            .signInWithEmailAndPassword(email: email, password: password)
            .then((uid) => {
                  Fluttertoast.showToast(msg: "Login Successful"),
                  Navigator.of(context).pushReplacement(MaterialPageRoute(
                      builder: (context) => DisciplinasScreen())),
                });
      } on FirebaseAuthException catch (error) {
        switch (error.code) {
          case "invalid-email":
            errorMessage = "Your email address appears to be malformed.";

            break;
          case "wrong-password":
            errorMessage = "Your password is wrong.";
            break;
          case "user-not-found":
            errorMessage = "User with this email doesn't exist.";
            break;
          case "user-disabled":
            errorMessage = "User with this email has been disabled.";
            break;
          case "too-many-requests":
            errorMessage = "Too many requests";
            break;
          case "operation-not-allowed":
            errorMessage = "Signing in with Email and Password is not enabled.";
            break;
          default:
            errorMessage = "An undefined Error happened.";
        }
        Fluttertoast.showToast(msg: errorMessage!);
        print(error.code);
      }
    }
  }
}

注册

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';
import 'package:fluttertoast/fluttertoast.dart';
import '../../disciplinas/disciplinas_screen.dart';
import '../models/user_model.dart';

class RegistrationScreen extends StatefulWidget {
  RegistrationScreen({Key? key}) : super(key: key);

  @override
  State createState() => _RegistrationScreenState();
}

class _RegistrationScreenState extends State {
  final _auth = FirebaseAuth.instance;

  // our form key
  final _formKey = GlobalKey();
  //editing Controller
  final firstNameEditingController = new TextEditingController();
  // final secondNameEditingController = new TextEditingController();
  final emailEditingController = new TextEditingController();
  final passwordEditingController = new TextEditingController();
  final confirmPassWordEditingController = new TextEditingController();

  String? errorMessage;

  @override
  Widget build(BuildContext context) {
    // first name field
    final firstNameField = TextFormField(
      style: Theme.of(context).textTheme.headline6,
      autofocus: false,
      controller: firstNameEditingController,
      keyboardType: TextInputType.name,
      validator: (value) {
        RegExp regex = new RegExp(r'^.{3,}$');
        if (value!.isEmpty) {
          return ('Insira um Nome');
        }
        if (!regex.hasMatch(value)) {
          return ('Utilize 3 ou mais carateres');
        }
        return null;
      },
      onSaved: (value) {
        firstNameEditingController.text = value!;
      },
      textInputAction: TextInputAction.next,
      decoration: InputDecoration(
        prefixIcon: Icon(
          Icons.account_circle,
          color: Color.fromARGB(255, 28, 209, 216),
        ),
        contentPadding: EdgeInsets.fromLTRB(20, 15, 20, 15),
        hintText: 'Primeiro Nome',
        hintStyle: Theme.of(context).textTheme.headline2,
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(15),
          //borderSide: BorderSide(color: Colors.pink, width: 5.0),
        ),
      ),
    );

    // email field
    final emailField = TextFormField(
      style: Theme.of(context).textTheme.headline6,
      autofocus: false,
      controller: emailEditingController,
      keyboardType: TextInputType.emailAddress,
      validator: (value) {
        if (value!.isEmpty) {
          return ('Email obrigatório');
        }
        // reg expression for email validation
        if (!RegExp("^[a-zA-Z0-9+_.-]+@[a-zA-Z0-9.-]+.[a-z]").hasMatch(value)) {
          return ('Insira um email válifo');
        }
        return null;
      },
      onSaved: (value) {
        emailEditingController.text = value!;
      },
      textInputAction: TextInputAction.next,
      decoration: InputDecoration(
        prefixIcon: Icon(
          Icons.mail,
          color: Color.fromARGB(255, 28, 209, 216),
        ),
        contentPadding: EdgeInsets.fromLTRB(20, 15, 20, 15),
        hintText: 'Email',
        hintStyle: Theme.of(context).textTheme.headline2,
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(15),
          //borderSide: BorderSide(color: Colors.pink, width: 5.0),
        ),
      ),
    );

    // password field
    final passwordField = TextFormField(
      style: Theme.of(context).textTheme.headline6,
      autofocus: false,
      controller: passwordEditingController,
      obscureText: true,
      validator: (value) {
        RegExp regex = new RegExp(r'^.{6,}$');
        if (value!.isEmpty) {
          return ('Insira uma password');
        }
        if (!regex.hasMatch(value)) {
          return ('Utilize 6 ou mais carateres');
        }
      },
      onSaved: (value) {
        passwordEditingController.text = value!;
      },
      textInputAction: TextInputAction.next,
      decoration: InputDecoration(
        prefixIcon: Icon(
          Icons.vpn_key,
          color: Color.fromARGB(255, 28, 209, 216),
        ),
        contentPadding: EdgeInsets.fromLTRB(20, 15, 20, 15),
        hintText: 'Password',
        hintStyle: Theme.of(context).textTheme.headline2,
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(15),
          //borderSide: BorderSide(color: Colors.pink, width: 5.0),
        ),
      ),
    );

    // confirm password field
    final confirmPasswordField = TextFormField(
      style: Theme.of(context).textTheme.headline6,
      autofocus: false,
      controller: confirmPassWordEditingController,
      obscureText: true,
      validator: (value) {
        if (confirmPassWordEditingController.text !=
            passwordEditingController.text) {
          return ('As palavras-passe não coincidem. Tente novamente.');
        }
        return null;
      },
      onSaved: (value) {
        confirmPassWordEditingController.text = value!;
      },
      textInputAction: TextInputAction.done,
      decoration: InputDecoration(
        prefixIcon: Icon(
          Icons.vpn_key,
          color: Color.fromARGB(255, 28, 209, 216),
        ),
        contentPadding: EdgeInsets.fromLTRB(20, 15, 20, 15),
        hintText: 'Confirma a Password',
        hintStyle: Theme.of(context).textTheme.headline2,
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(15),
          //borderSide: BorderSide(color: Colors.pink, width: 5.0),
        ),
      ),
    );

    // signup field
    final signUpButton = Material(
      elevation: 5,
      borderRadius: BorderRadius.circular(15),
      color: Color.fromARGB(255, 28, 209, 216),
      child: MaterialButton(
        padding: EdgeInsets.fromLTRB(20, 15, 20, 15),
        minWidth: MediaQuery.of(context).size.width,
        onPressed: () {
          signUp(emailEditingController.text, passwordEditingController.text);
        },
        child: Text(
          'Sign up',
          textAlign: TextAlign.center,
          style: Theme.of(context).textTheme.headline6,
        ),
      ),
    );

    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.transparent,
        elevation: 0,
        leading: IconButton(
          icon: Icon(
            Icons.arrow_back,
            color: Color.fromARGB(255, 28, 209, 216),
          ),
          onPressed: () {
            // passing this to our root
            Navigator.of(context).pop();
          },
        ),
      ),
      body: Center(
        child: SingleChildScrollView(
          child: Container(
            // color: Colors.white,
            child: Padding(
              padding: const EdgeInsets.all(36.0),
              child: Form(
                key: _formKey,
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: [
                    SizedBox(
                      height: 200,
                      child: Image.asset(
                        'assets/images/owl_white.png',
                        fit: BoxFit.contain,
                      ),
                    ),
                    SizedBox(height: 0),
                    firstNameField,
                    // SizedBox(height: 15),
                    // secondNameField,
                    SizedBox(height: 15),
                    emailField,
                    SizedBox(height: 15),
                    passwordField,
                    SizedBox(height: 15),
                    confirmPasswordField,
                    SizedBox(height: 15),
                    signUpButton,
                  ],
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }

  void signUp(String email, String password) async {
    if (_formKey.currentState!.validate()) {
      try {
        await _auth
            .createUserWithEmailAndPassword(email: email, password: password)
            .then((value) => {postDetailsToFirestore()})
            .catchError((e) {
          Fluttertoast.showToast(msg: e!.message);
        });
      } on FirebaseAuthException catch (error) {
        switch (error.code) {
          case "invalid-email":
            errorMessage = "Your email address appears to be malformed.";
            break;
          case "wrong-password":
            errorMessage = "Your password is wrong.";
            break;
          case "user-not-found":
            errorMessage = "User with this email doesn't exist.";
            break;
          case "user-disabled":
            errorMessage = "User with this email has been disabled.";
            break;
          case "too-many-requests":
            errorMessage = "Too many requests";
            break;
          case "operation-not-allowed":
            errorMessage = "Signing in with Email and Password is not enabled.";
            break;
          default:
            errorMessage = "An undefined Error happened.";
        }
        Fluttertoast.showToast(msg: errorMessage!);
        print(error.code);
      }
    }
  }

  postDetailsToFirestore() async {
    // calling our firestore
    // calling our model
    // sending these values

    FirebaseFirestore firebaseFirestore = FirebaseFirestore.instance;
    User? user = _auth.currentUser;

    UserModel userModel = UserModel();

    // writing all the values
    userModel.email = user!.email;
    userModel.uid = user.uid;
    userModel.firstName = firstNameEditingController.text;

    await firebaseFirestore
        .collection('users')
        .doc(user.uid)
        .set(userModel.toMap());
    Fluttertoast.showToast(msg: 'Conta criada :)');

    Navigator.pushAndRemoveUntil(
        context,
        MaterialPageRoute(builder: (context) => DisciplinasScreen()),
        (route) => false);
  }
}