Form Validation Error

[sid86-dev]

After clicking Login button the screen is changing even if the text and password fields are empty

import 'package:first_app/utils/approutes.dart';
import 'package:flutter/material.dart';

class Login extends StatefulWidget {
  @override
  _LoginState createState() => _LoginState();
}

class _LoginState extends State<Login> {
  String name = "";
  bool changebtn = false;
  final _formkey = GlobalKey<FormState>();

  movetohome(BuildContext context) async {
    if (_formkey.currentState!.validate()) {
      setState(() {
        changebtn = true;
      });
    }
    // push to move to next route

    await Future.delayed(Duration(seconds: 1));
    await Navigator.pushNamed(context, Approutes.homeRoute);
    setState(() {
      changebtn = false;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Material(
        color: Colors.white,
        child: SingleChildScrollView(
          child: Form(
            key: _formkey,
            child: Column(
              children: [
                Image.asset(
                  "assets/images/top.png",
                  fit: BoxFit.cover,
                ),
                SizedBox(
                  height: 80.0,
                ),
                Text(
                  "Welcome $name",
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 28),
                ),
                Padding(
                  padding: const EdgeInsets.symmetric(
                      vertical: 30.0, horizontal: 40.0),
                  child: Column(
                    children: [
                      TextFormField(
                        onChanged: (value) {
                          name = value;
                          setState(() {});
                        },
                        style: TextStyle(fontSize: 20),
                        decoration: InputDecoration(
                            hintText: "Enter username", labelText: "username"),
                        validator: (value) {
                          if (value!.isEmpty) {
                            return "Username cannot be empty";
                          }
                          return null;
                        },
                      ),
                      TextFormField(
                        style: TextStyle(fontSize: 20),
                        obscureText: true,
                        decoration: InputDecoration(
                            hintText: "Enter password", labelText: "password"),
                        validator: (value) {
                          if (value!.isEmpty) {
                            return "Password cannot be empty";
                          } else if (value.length < 6) {
                            return "Password length should be atleast 6";
                          }
                          return null;
                        },
                      ),
                      SizedBox(
                        height: 50.0,
                      ),
                      Material(
                        color: Colors.pinkAccent,
                        borderRadius: BorderRadius.circular(changebtn ? 60 : 8),
                        child: InkWell(
                          splashColor: Colors.yellow,
                          onTap: () => movetohome(context),
                          child: AnimatedContainer(
                            duration: Duration(seconds: 1),
                            width: changebtn ? 60 : 160,
                            height: 60,
                            // styling

                            alignment: Alignment.center,
                            child: changebtn
                                ? Icon(Icons.done)
                                : Text(
                                    "Login",
                                    style: TextStyle(
                                        fontSize: 25,
                                        color: Colors.white,
                                        fontWeight: FontWeight.bold),
                                  ),
                          ),
                        ),
                      ),
                    ],
                  ),
                ),
              ],
            ),
          ),
        ));
  }
}

[smv8960]

I matched your code with mine, they both are same, It ran on my system and worked well.
you should save the file and try to reopen on vscode and run the app,
it may work,
if not then you should create new project and paste all code in that project and try it there

[Divyesh3543]

i will make sure it will work
validator: (String? value) {
if (value == null || value.isEmpty) {
return "Please enter some text";
}
return null;
},

[Umar-Waseem]

Fixed the form validation issue, have a look at my code

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

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

  @override
  State<LoginPage> createState() => _LoginPageState();
}

class _LoginPageState extends State<LoginPage> {
  bool buttonChanged = false;
  String name = "";
  final _formKey = GlobalKey<FormState>();

  @override
  Widget build(BuildContext context) {
    return Material(
      color: Colors.grey[500],
      child: Form(
        key: _formKey,
        child: Column(
          children: [
            const CircleAvatar(backgroundImage: AssetImage('images/login.jpg')),
            const SizedBox(height: 15.0),
            Text('Welcome $name',
                style: const TextStyle(
                    fontSize: 24.0, fontWeight: FontWeight.bold)),
            const SizedBox(height: 15.0),
            Padding(
                padding:
                    const EdgeInsets.symmetric(horizontal: 15, vertical: 32),
                child: Column(
                  children: [
                    TextFormField(
                      decoration: const InputDecoration(
                          hintText: 'Enter the username',
                          labelText: 'UserName:'),
                      onChanged: (value) {
                        name = value;
                        setState(() {});
                      },
                      validator: (value) {
                        if (value == null || value.isEmpty) {
                          return 'Please enter the username';
                        }
                        
                          return null;
                        
                        
                      },
                    ),
                    TextFormField(
                      obscureText: true,
                      decoration: const InputDecoration(
                          hintText: 'Enter the password',
                          labelText: 'Password:'),
                      validator: (value) {
                        if (value == null || value.isEmpty) {
                          return "Please enter password";
                        } else if (value.isNotEmpty && value.length < 6) {
                          return "Password must be at least 6 characters";
                        } else if (value.isNotEmpty && value.length > 12) {
                          return "Password must be less than 12 characters";
                        }

                        return null;
                      },
                    ),
                    const SizedBox(height: 15.0),
                    Material(
                        borderRadius:
                            BorderRadius.circular(buttonChanged ? 50.0 : 10.0),
                        color: Colors.blue,
                        child: InkWell(
                          splashColor: Colors.grey[7],
                          onTap: () => moveToHome(context),
                          child: AnimatedContainer(
                            duration: const Duration(seconds: 1),
                            width: buttonChanged ? 50 : 130,
                            height: 50,
                            alignment: Alignment.center,
                            child: buttonChanged
                                ? const Icon(Icons.done)
                                : const Text(
                                    'Login',
                                    style: TextStyle(
                                        color: Colors.white,
                                        fontWeight: FontWeight.bold,
                                        fontSize: 16),
                                  ),
                          ),
                        ))
                  ],
                ))
          ],
        ),
      ),
    );
  }

  moveToHome(BuildContext context) async {
    if (_formKey.currentState!.validate()) {
      setState(() {
        buttonChanged = true;
        
      }
      );
      await Future.delayed(const Duration(seconds: 1));
      await Navigator.pushNamed(context, route.home);
      setState(() {
        buttonChanged = false;
      });
      
    }
    else{
      setState(() {
        buttonChanged = false;
      });
    }

  }
}