Instance member 'setState' can't be accessed using static access-CodePudding

I am trying to use CheckBox in flutter, but I am facing a problem using setState inside of it. This the code of the checkbox.

Checkbox(
                    value: check1,
                    checkColor: Colors.white,
                    activeColor: Colors.green,
                    onChanged: (bool? value1) {
                      State.setState(() {
                        check1 = value1;
                      });
                    },
                  ),

And this is the whole code

// ignore_for_file: sized_box_for_whitespace, duplicate_ignore, avoid_unnecessary_containers, avoid_print

// ignore: unnecessary_import
import 'dart:ui';

import 'package:flutter/material.dart';

// ignore: must_be_immutable
class Register extends StatelessWidget {
  var emailController = TextEditingController();
  var passwordController = TextEditingController();
  var firstNameController = TextEditingController();
  var lastNameController = TextEditingController();
  var userNameController = TextEditingController();
  var confirmPasswordController = TextEditingController();
  bool? check1 = false;

  Register({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        leading: const Icon(
          Icons.menu,
        ),
        actions: const [
          IconButton(onPressed: sSearch, icon: Icon(Icons.search)),
          IconButton(
            onPressed: noNotification,
            icon: Icon(Icons.notification_important_rounded),
          )
        ],
        centerTitle: true,
        backgroundColor: const Color.fromARGB(255, 80, 146, 4),
        elevation: 15,
      ),
      body: Padding(
        padding: const EdgeInsets.all(20.0),
        child: Center(
          child: SingleChildScrollView(
            child:
                Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
              Container(
                alignment: AlignmentDirectional.center,
                child: const Text(
                  'Register',
                  style: TextStyle(fontSize: 40, fontWeight: FontWeight.bold),
                ),
              ),
              const SizedBox(
                height: 40,
              ),
              Row(
                children: [
                  Expanded(
                    child: TextFormField(
                      controller: firstNameController,
                      keyboardType: TextInputType.text,
                      onFieldSubmitted: (String value) {
                        print(value);
                      },
                      onChanged: (String value) {
                        print(value);
                      },
                      decoration: const InputDecoration(
                          prefixIcon: Icon(Icons.person),
                          labelText: 'First Name',
                          border: OutlineInputBorder()),
                    ),
                  ),
                  Expanded(
                    child: TextFormField(
                      controller: lastNameController,
                      keyboardType: TextInputType.text,
                      onFieldSubmitted: (String value) {
                        print(value);
                      },
                      onChanged: (String value) {
                        print(value);
                      },
                      decoration: const InputDecoration(
                          prefixIcon: Icon(Icons.person),
                          labelText: 'Last Name',
                          border: OutlineInputBorder()),
                    ),
                  ),
                ],
              ),
              const SizedBox(
                height: 10,
              ),
              TextFormField(
                controller: userNameController,
                keyboardType: TextInputType.text,
                onFieldSubmitted: (String value) {
                  print(value);
                },
                onChanged: (String value) {
                  print(value);
                },
                decoration: const InputDecoration(
                    prefixIcon: Icon(Icons.supervised_user_circle),
                    labelText: 'UserName',
                    border: OutlineInputBorder()),
              ),
              const SizedBox(
                height: 10,
              ),
              TextFormField(
                controller: emailController,
                keyboardType: TextInputType.emailAddress,
                onFieldSubmitted: (String value) {
                  print(value);
                },
                onChanged: (String value) {
                  print(value);
                },
                decoration: const InputDecoration(
                    prefixIcon: Icon(Icons.email),
                    labelText: 'Email Address',
                    border: OutlineInputBorder()),
              ),
              const SizedBox(
                height: 10,
              ),
              TextFormField(
                controller: passwordController,
                keyboardType: TextInputType.visiblePassword,
                obscureText: true,
                onFieldSubmitted: (String value) {
                  print(value);
                },
                onChanged: (String value) {
                  print(value);
                },
                decoration: const InputDecoration(
                    prefixIcon: Icon(Icons.lock),
                    suffixIcon: Icon(Icons.remove_red_eye),
                    labelText: 'Password',
                    border: OutlineInputBorder()),
              ),
              const SizedBox(
                height: 10,
              ),
              TextFormField(
                controller: confirmPasswordController,
                keyboardType: TextInputType.visiblePassword,
                obscureText: true,
                onFieldSubmitted: (String value) {
                  print(value);
                },
                onChanged: (String value) {
                  print(value);
                },
                decoration: const InputDecoration(
                    prefixIcon: Icon(Icons.lock),
                    suffixIcon: Icon(Icons.remove_red_eye),
                    labelText: 'Confirm Password',
                    border: OutlineInputBorder()),
              ),
              const SizedBox(
                height: 20,
              ),
              Container(
                width: double.infinity,
                color: Colors.green,
                child: MaterialButton(
                  onPressed: () {
                    print(emailController.text);
                    print(passwordController.text);
                  },
                  child: const Text(
                    'LOGIN',
                    style: TextStyle(
                        fontSize: 20,
                        fontWeight: FontWeight.bold,
                        color: Colors.white),
                  ),
                ),
              ),
              const SizedBox(
                height: 10,
              ),
              Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Checkbox(
                    value: check1,
                    checkColor: Colors.white,
                    activeColor: Colors.green,
                    onChanged: (bool? value1) {
                      State.setState(() {
                        check1 = value1;
                      });
                    },
                  ),
                ],
              )
            ]),
          ),
        ),
      ),
    );
  }
}

void noNotification() {
  // ignore: avoid_print
  print('Notification Clicked');
}

void sSearch() {
// ignore: avoid_print
  print('Search Clicked');
}

I didn't understand what was the problem, I would be appreciated if someone could explain it to me.

CodePudding user response：

for using setstate your widget should be stateful widget check the code below

// ignore_for_file: sized_box_for_whitespace, duplicate_ignore, avoid_unnecessary_containers, avoid_print

import 'package:flutter/material.dart';

class Register extends StatefulWidget {
  const Register({super.key});

  @override
  State<Register> createState() => _RegisterState();
}

class _RegisterState extends State<Register> {
  var emailController = TextEditingController();

  var passwordController = TextEditingController();

  var firstNameController = TextEditingController();

  var lastNameController = TextEditingController();

  var userNameController = TextEditingController();

  var confirmPasswordController = TextEditingController();

  bool? check1 = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        leading: const Icon(
          Icons.menu,
        ),
        actions: const [
          IconButton(onPressed: sSearch, icon: Icon(Icons.search)),
          IconButton(
            onPressed: noNotification,
            icon: Icon(Icons.notification_important_rounded),
          )
        ],
        centerTitle: true,
        backgroundColor: const Color.fromARGB(255, 80, 146, 4),
        elevation: 15,
      ),
      body: Padding(
        padding: const EdgeInsets.all(20.0),
        child: Center(
          child: SingleChildScrollView(
            child:
                Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
              Container(
                alignment: AlignmentDirectional.center,
                child: const Text(
                  'Register',
                  style: TextStyle(fontSize: 40, fontWeight: FontWeight.bold),
                ),
              ),
              const SizedBox(
                height: 40,
              ),
              Row(
                children: [
                  Expanded(
                    child: TextFormField(
                      controller: firstNameController,
                      keyboardType: TextInputType.text,
                      onFieldSubmitted: (String value) {
                        print(value);
                      },
                      onChanged: (String value) {
                        print(value);
                      },
                      decoration: const InputDecoration(
                          prefixIcon: Icon(Icons.person),
                          labelText: 'First Name',
                          border: OutlineInputBorder()),
                    ),
                  ),
                  Expanded(
                    child: TextFormField(
                      controller: lastNameController,
                      keyboardType: TextInputType.text,
                      onFieldSubmitted: (String value) {
                        print(value);
                      },
                      onChanged: (String value) {
                        print(value);
                      },
                      decoration: const InputDecoration(
                          prefixIcon: Icon(Icons.person),
                          labelText: 'Last Name',
                          border: OutlineInputBorder()),
                    ),
                  ),
                ],
              ),
              const SizedBox(
                height: 10,
              ),
              TextFormField(
                controller: userNameController,
                keyboardType: TextInputType.text,
                onFieldSubmitted: (String value) {
                  print(value);
                },
                onChanged: (String value) {
                  print(value);
                },
                decoration: const InputDecoration(
                    prefixIcon: Icon(Icons.supervised_user_circle),
                    labelText: 'UserName',
                    border: OutlineInputBorder()),
              ),
              const SizedBox(
                height: 10,
              ),
              TextFormField(
                controller: emailController,
                keyboardType: TextInputType.emailAddress,
                onFieldSubmitted: (String value) {
                  print(value);
                },
                onChanged: (String value) {
                  print(value);
                },
                decoration: const InputDecoration(
                    prefixIcon: Icon(Icons.email),
                    labelText: 'Email Address',
                    border: OutlineInputBorder()),
              ),
              const SizedBox(
                height: 10,
              ),
              TextFormField(
                controller: passwordController,
                keyboardType: TextInputType.visiblePassword,
                obscureText: true,
                onFieldSubmitted: (String value) {
                  print(value);
                },
                onChanged: (String value) {
                  print(value);
                },
                decoration: const InputDecoration(
                    prefixIcon: Icon(Icons.lock),
                    suffixIcon: Icon(Icons.remove_red_eye),
                    labelText: 'Password',
                    border: OutlineInputBorder()),
              ),
              const SizedBox(
                height: 10,
              ),
              TextFormField(
                controller: confirmPasswordController,
                keyboardType: TextInputType.visiblePassword,
                obscureText: true,
                onFieldSubmitted: (String value) {
                  print(value);
                },
                onChanged: (String value) {
                  print(value);
                },
                decoration: const InputDecoration(
                    prefixIcon: Icon(Icons.lock),
                    suffixIcon: Icon(Icons.remove_red_eye),
                    labelText: 'Confirm Password',
                    border: OutlineInputBorder()),
              ),
              const SizedBox(
                height: 20,
              ),
              Container(
                width: double.infinity,
                color: Colors.green,
                child: MaterialButton(
                  onPressed: () {
                    print(emailController.text);
                    print(passwordController.text);
                  },
                  child: const Text(
                    'LOGIN',
                    style: TextStyle(
                        fontSize: 20,
                        fontWeight: FontWeight.bold,
                        color: Colors.white),
                  ),
                ),
              ),
              const SizedBox(
                height: 10,
              ),
              Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Checkbox(
                    value: check1,
                    checkColor: Colors.white,
                    activeColor: Colors.green,
                    onChanged: (bool? value1) {
                      setState(() {
                        check1 = value1;
                      });
                    },
                  ),
                ],
              )
            ]),
          ),
        ),
      ),
    );
  }
}

void noNotification() {
  // ignore: avoid_print
  print('Notification Clicked');
}

void sSearch() {
// ignore: avoid_print
  print('Search Clicked');
}