I am new to flask. I am getting this Exception on switching between signIn and signUp pages. Can someone help? Code for signin and signup pages are added below.

code for SignUp

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

  @override
  State<RegisterView> createState() => _RegisterViewState();
}

class _RegisterViewState extends State<RegisterView> {
  late final TextEditingController _email;
  late final TextEditingController _password;

  @override
  void initState() {
    _email = TextEditingController();
    _password = TextEditingController();
    super.initState();
  }

  @override
  void dispose() {
    _email = TextEditingController();
    _password = TextEditingController();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Register'),
      ),
      body: Column(
        children: [
          TextField(
            controller: _email,
            obscureText: false,
            enableSuggestions: false,
            autocorrect: false,
            keyboardType: TextInputType.emailAddress,
            decoration: const InputDecoration(
              hintText: 'Enter your email here',
            ),
          ),
          TextField(
            controller: _password,
            obscureText: true,
            enableSuggestions: false,
            autocorrect: false,
            keyboardType: TextInputType.visiblePassword,
            decoration: const InputDecoration(
              hintText: 'Enter your password here',
            ),
          ),
          TextButton(
            onPressed: () async {
              final email = _email.text;
              final password = _password.text;
              try {
                // ignore: non_constant_identifier_names
                final UserCredential = await FirebaseAuth.instance.createUserWithEmailAndPassword(
                  email: email, 
                  password: password,
                );
                print(UserCredential);
              } on FirebaseAuthException catch (e) {
                if (e.code == 'weak-password') {
                  print('Weak password');
                } else if (e.code == 'email-already-in-use') {
                  print('Email is already in use');
                } else if (e.code == 'invalid-email') {
                  print('Invalid email');
                }
              } catch (e) {
                print('Something bad happened');
              }
                        
            },
            child: const Text('Register'),
          ),
          TextButton(
            onPressed: () {
              Navigator.of(context).pushNamedAndRemoveUntil(
                '/login', 
                (route) => false
              );
            }, 
            child: const Text('Already registered? Login here!'),
          ),
        ],
      ),
    );  
  }
}

'''

Code for SignIn

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

  @override
  State<LoginView> createState() => _LoginViewState();
}

class _LoginViewState extends State<LoginView> {
  late final TextEditingController _email;
  late final TextEditingController _password;

  @override
  void initState() {
    _email = TextEditingController();
    _password = TextEditingController();
    super.initState();
  }

  @override
  void dispose() {
    _email = TextEditingController();
    _password = TextEditingController();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Login'),
      ),
      body: Column(
        children: [
          TextField(
            controller: _email,
            obscureText: false,
            enableSuggestions: false,
            autocorrect: false,
            keyboardType: TextInputType.emailAddress,
            decoration: const InputDecoration(
              hintText: 'Enter your email here',
            ),
          ),
          TextField(
            controller: _password,
            obscureText: true,
            enableSuggestions: false,
            autocorrect: false,
            keyboardType: TextInputType.visiblePassword,
            decoration: const InputDecoration(
              hintText: 'Enter your password here',
            ),
          ),
          TextButton(
            onPressed: () async {
              final email = _email.text;
              final password = _password.text;
              try {
                // ignore: non_constant_identifier_names
                final UserCredential = await FirebaseAuth.instance.signInWithEmailAndPassword(
                  email: email, 
                  password: password,
                );
                print(UserCredential);
              } on FirebaseAuthException catch (e) {
                if (e.code == 'user-not-found') {
                  print('User not found');
                } else if (e.code == 'wrong-password') {
                  print('Wrong Password');
                }
              } catch (e) {
                print('Something bad happened');
                print(e.runtimeType);
                print(e);
              }
            },
            child: const Text('Login'),
          ),
          TextButton(
            onPressed: () {
              Navigator.of(context).pushNamedAndRemoveUntil(
                '/register', 
                (route) => false
              );
            }, 
            child: const Text('Not registered yet? Register here!'),
          ),
        ],
      ),
    ); 
  }
}

'''

CodePudding user response：

see dispose method, you're initializing the controllers once again, because copy paste code I guess

it should be

@override
  void dispose() {
    _email.dispose();
    _password.dispose();
    super.dispose();
  }