颤振和Firebase认证问题

Question

今天我有一个问题与Firebase认证服务。那我来解释一下情况。我有一个页面，让你选择一种类型的用户，如果你选择"客人"你将在没有登录的情况下通过应用程序的仪表板页面Nav()，但如果选择"登录";app会将您推送到登录页面Login()。

class SelectUser extends StatelessWidget {
const SelectUser({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: const Color(0xFF20348F),
body: Padding(
padding: const EdgeInsets.all(20.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.end,
children: [
Container(
padding: const EdgeInsets.all(15.0),
margin: const EdgeInsets.all(15.0),
alignment: Alignment.center,
decoration: BoxDecoration(
color: Colors.amber,
borderRadius: BorderRadius.circular(45),
),
child: TextButton(
child: const Text('Guest'),
onPressed: () {
Navigator.pushAndRemoveUntil(
context,
MaterialPageRoute(
builder: (BuildContext context) => const Nav(),
),
(route) => false,
);
},
style: TextButton.styleFrom(
primary: const Color(0xFF20348F),
textStyle: const TextStyle(
fontSize: 30,
fontWeight: FontWeight.bold,
)),
),
),
Container(
padding: const EdgeInsets.all(15.0),
margin: const EdgeInsets.all(15.0),
alignment: Alignment.center,
decoration: BoxDecoration(
color: Colors.amber,
borderRadius: BorderRadius.circular(45),
),
child: TextButton(
child: const Text('Sign-In'),
onPressed: () {
Navigator.push(context, MaterialPageRoute(builder: (contex) {
return const Login();
}));
},
style: TextButton.styleFrom(
primary: const Color(0xFF20348F),
textStyle: const TextStyle(
fontSize: 30,
fontWeight: FontWeight.bold,
)),
),
),
],
),
),
);
}
}

在Nav()我使用BottomNavigationBarItem，并有几个小部件包括Proflie()在里面。我已经测试了注册，注销和注册功能，一切都很好，但当我试图在Proflie()中棘手时，我面临……我们来看一个奇怪的问题。首先让我向您展示Proflie()中的代码。

class Profile extends StatefulWidget {
const Profile({Key? key}) : super(key: key);
@override
_ProfileState createState() => _ProfileState();
}
class _ProfileState extends State<Profile> {
String? _email;
DateTime? _creationTime;
DateTime? _lastSignIn;
bool? _status;
@override
Widget build(BuildContext context) {
userStatus();
return userForm();
}
userStatus() {
FirebaseAuth.instance.authStateChanges().listen((event) {
if (event == null) {
_status = false;
} else {
_status = true;
_email = FirebaseAuth.instance.currentUser!.email;
_creationTime =
FirebaseAuth.instance.currentUser!.metadata.creationTime;
_lastSignIn =
FirebaseAuth.instance.currentUser!.metadata.lastSignInTime;
}
});
}
Widget userForm() {
if (_status == true) {
return Scaffold(
appBar: defaultAppBar('Profile'),
body: Center(
child: ListView(
padding: const EdgeInsets.all(20),
children: [
Container(
margin: const EdgeInsets.all(30),
child: Text(
'Email: $_email',
style: const TextStyle(
fontSize: 18, fontWeight: FontWeight.bold),
),
),
Container(
margin: const EdgeInsets.all(30),
child: Text(
'Creation Time: $_creationTime',
style: const TextStyle(
fontSize: 18, fontWeight: FontWeight.bold),
),
),
Container(
margin: const EdgeInsets.all(30),
child: Text(
'Last Sign-In: $_lastSignIn',
style: const TextStyle(
fontSize: 18, fontWeight: FontWeight.bold),
),
),
const SizedBox(height: 45),
button('Change password', 1),
const SizedBox(height: 18),
button('Change email', 2),
const SizedBox(height: 18),
button('Sign-out', 0),
],
),
),
);
} else {
return Center(
child: ListView(
padding: const EdgeInsets.all(14),
children: <Widget>[
const SizedBox(height: 100),
Container(
margin: const EdgeInsets.all(30),
child: const Center(
child: Text(
'Please sign-in to use this Feature',
style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
),
),
),
const SizedBox(height: 50),
button('Login', 3),
const SizedBox(height: 18),
button('Register', 4),
],
),
);
}
}
Widget button(String txt, int _nav) {
Color? _color = const Color(0xFF20348F);
if (_nav == 0) {
_color = Colors.red;
}
return TextButton(
style: TextButton.styleFrom(
primary: _color,
textStyle: const TextStyle(
fontSize: 20,
),
),
child: Text(txt),
onPressed: () {
if (_nav == 0) {
FirebaseAuth.instance.signOut();
Navigator.pushAndRemoveUntil(
context,
MaterialPageRoute(
builder: (BuildContext context) => const SelectUser(),
),
(route) => false,
);
} else {
Navigator.push(context, MaterialPageRoute(builder: (contex) {
if (_nav == 1) {
return const EditPass();
} else if (_nav == 2) {
return const EditEmail();
} else if (_nav == 3) {
return const Login();
} else {
return const Register();
}
}));
}
},
);
}
}

正如你所看到的，我正在尝试使用userStatus()来识别"用户"。和";Guest"我使用FirebaseAuth.instance.authStateChanges().listen((event)来检查Firebase认证中的用户状态(不确定我是否在做正确的方式，如果不是请教我如何检查用户状态)如果event == null这意味着现在没有用户登录。我将_status = false设置为" guest "应该在userForm()中找到else的案例。否则，_status = true表示用户已登录，userForm()应该转到if (_status == true)。

现在的问题是当我成功登录到Login()。在Profile()中，我最终得到了userForm()的else案例，但这不是全部!当我重新加载IDE时，结果是现在我在if (_status == true)的情况下。是的，就像我说的，这是一个奇怪的问题，应用程序第一次加载页面时，它会转到假情况，但当热重新加载时，它会转到真情况。我不太确定错误是来自Profile()或Login()。那我就不写Login()了。

class Login extends StatefulWidget {
const Login({Key? key}) : super(key: key);
@override
_LoginState createState() => _LoginState();
}
class _LoginState extends State<Login> {
final _formKey = GlobalKey<FormState>();
var _email = "";
var _password = "";
final emailController = TextEditingController();
final passwordController = TextEditingController();
bool _passwordVisible = true;
@override
void dispose() {
emailController.dispose();
passwordController.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return formLogin();
}
Widget formLogin() {
return Scaffold(
appBar: defaultAppBar('Sign-In'),
body: Center(
child: Form(
key: _formKey,
child: Padding(
padding: const EdgeInsets.all(32),
child: ListView(
children: [
buildEmail(),
const SizedBox(height: 24),
buildPassword('Password', 'Your password...'),
const SizedBox(height: 50),
button('Sign-in', 0),
const SizedBox(height: 24),
button('Sign-up', 1),
],
),
),
),
),
);
}
userLogin() async {
try {
await FirebaseAuth.instance
.signInWithEmailAndPassword(email: _email, password: _password);
Navigator.pushAndRemoveUntil(
context,
MaterialPageRoute(
builder: (BuildContext context) => const Nav(),
),
(route) => false,
);
} on FirebaseAuthException catch (e) {
if (e.code == 'user-not-found') {
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(
backgroundColor: Colors.amber,
content: Text(
"Email not found",
style: TextStyle(fontSize: 16.0, color: Colors.black),
),
),
);
} else if (e.code == 'wrong-password') {
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(
backgroundColor: Colors.amber,
content: Text(
"Password incorrect",
style: TextStyle(fontSize: 16.0, color: Colors.black),
),
),
);
}
}
}
TextButton button(String txt, int nav) {
return TextButton(
style: TextButton.styleFrom(
primary: const Color(0xFF20348F),
textStyle: const TextStyle(
fontSize: 20,
),
),
child: Text(txt),
onPressed: () {
if (nav == 0) {
if (_formKey.currentState!.validate()) {
setState(() {
_email = emailController.text;
_password = passwordController.text;
});
userLogin();
}
} else {
_formKey.currentState!.reset();
Navigator.push(context, MaterialPageRoute(builder: (contex) {
return const Register();
}));
}
},
);
}
Widget buildEmail() {
return TextFormField(
decoration: const InputDecoration(
labelText: 'Email',
hintText: '[e-mail]',
prefixIcon: Icon(Icons.mail_outline),
border: OutlineInputBorder(),
errorStyle: TextStyle(color: Colors.redAccent, fontSize: 15),
),
controller: emailController,
validator: MultiValidator([
RequiredValidator(errorText: "Email is required"),
EmailValidator(errorText: "The format of email is incorrect")
]),
keyboardType: TextInputType.emailAddress,
textInputAction: TextInputAction.done,
);
}
Widget buildPassword(String _txt1, String _txt2) {
return TextFormField(
obscureText: _passwordVisible,
decoration: InputDecoration(
labelText: _txt1,
hintText: _txt2,
suffixIcon: GestureDetector(
onTap: () {
setState(() {
_passwordVisible = !_passwordVisible;
});
},
child: Icon(
_passwordVisible ? Icons.visibility : Icons.visibility_off,
),
),
prefixIcon: const Icon(Icons.vpn_key_outlined),
border: const OutlineInputBorder(),
errorStyle: const TextStyle(color: Colors.redAccent, fontSize: 15),
),
controller: passwordController,
validator: RequiredValidator(errorText: "Password is required"),
textInputAction: TextInputAction.done,
);
}
}

如果你们能帮我，我会很感激的。

Answer 1

如果你可以创建一个。gist，这将对你有帮助，也在你的个人资料页面，我可以看到的问题是，你正在听取用户的变化在构建中，这是非常不实际的，在构建中添加它，因为flutter会调用构建方法多次，构建应该是干净的，也有潜在的内存泄漏，因为你没有处置流。