Was building UI with TextField() in Flutter, I defined the controller in state and tried to use that defined emailController and passwordController in TextField() but it says "Invalid constant value.". I tried to resolve it but didn't work. Here is the code for login_screen.dart

import 'package:flutter/material.dart';
import 'package:rider_app/routes/routing_constants.dart';

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

  @override
  State<LoginScreen> createState() => _LoginScreenState();
}

class _LoginScreenState extends State<LoginScreen> {
  final TextEditingController emailController = TextEditingController();
  final TextEditingController passwordController = TextEditingController();
  final _validate = false;
  
  // @override
  // void dispose() {
  //   emailController.dispose();
  //   passwordController.dispose();
  //   super.dispose();
  // }


  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      body: SingleChildScrollView(
        child: Column(
          children: [
            const SizedBox(
              height: 40.0,
            ),
            const Center(
                child: Image(
              image: AssetImage("lib/assets/images/logo.png"),
              width: 200.0,
              height: 200.0,
              alignment: Alignment.center,
            )),
            const SizedBox(
              height: 2.0,
            ),
            const Text(
              "Login as a Rider",
              textAlign: TextAlign.center,
              style: TextStyle(fontSize: 25.0, fontFamily: "Brand Bold"),
            ),
            Padding(
              padding:
                  const EdgeInsets.symmetric(horizontal: 30.0, vertical: 10.0),
              child: Column(
                children: [
                  const SizedBox(
                    height: 10.0,
                  ),
                  const TextField(
                    
                    keyboardType: TextInputType.emailAddress,
                    decoration: InputDecoration(
                      labelText: "Email",
                      labelStyle: TextStyle(
                        fontSize: 15.0,
                      ),
                      hintText: "Email address",
                      hintStyle: TextStyle(fontSize: 12.0, color: Colors.grey),
                      // focusedBorder: OutlineInputBorder(
                      //   borderSide:
                      //       BorderSide(width: 1.0, color: Colors.blueAccent),
                      // ),
                      // enabledBorder: OutlineInputBorder(
                      //   borderSide: BorderSide(width: 1.0),
                      // ),
                    ),
                    style: TextStyle(fontSize: 15.0),
                    controller: emailController,
                    
                  ),
                  const SizedBox(
                    height: 10.0,
                  ),
                  const TextField(
                    controller: passwordController,
                    keyboardType: TextInputType.visiblePassword,
                    decoration: InputDecoration(
                      labelText: "Password",
                      labelStyle: TextStyle(fontSize: 15.0),
                      hintText: "Your password",
                      hintStyle: TextStyle(fontSize: 12.0, color: Colors.grey),
                      // focusedBorder: OutlineInputBorder(
                      //   borderSide: BorderSide(width: 1.0, color: Colors.blueAccent),
                    ),
                    // enabledBorder: OutlineInputBorder(
                    //   borderSide: BorderSide(width: 1.0)
                    // )
                    // ),
                    obscureText: true,
                    style: TextStyle(fontSize: 15.0),
                  ),
                  const SizedBox(
                    height: 45.0,
                  ),
                  ElevatedButton(
                    onPressed: () {
                      debugPrint("Logged In");
                      Navigator.pushNamed(context, homeScreen);
                    },
                    child: const Padding(
                      padding: EdgeInsets.symmetric(
                          horizontal: 23, vertical: 11),
                      child: Text(
                        'Login',
                        style: TextStyle(
                            fontSize: 18,
                            fontFamily: "Brand Bold",
                            fontWeight: FontWeight.w500),
                      ),
                    ),
                  ),
                ],
              ),
            ),
            FlatButton(
                onPressed: () {
                  Navigator.pushNamed(context, signUpScreen);
                },
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: const [
                    Text(
                      "Don't have Account?",
                      style: TextStyle(
                          fontWeight: FontWeight.w400,
                          fontFamily: "Brand-Regular"),
                    ),
                    Text(
                      " Register Here.",
                      style: TextStyle(
                          fontFamily: "Brand-Regular",
                          fontWeight: FontWeight.w600),
                    )
                  ],
                ))
          ],
        ),
      ),
    );
  }
}

The controller defination is okay but as I try to assign controller to the TextField() controller, the error is thrown. Screenshot attached herewith:

Have any idea ?? let me know, even suggetion is appreciated. Thank you!

GitHub Repo: Project Link Github

CodePudding user response：

Try removing the "const" before TextField, that should resolve the error.

CodePudding user response：

Remove const keywords at the beginning of TextField widgets.

CodePudding user response：

Try removing the const modifier from the TextField.