Checkbox toggle within dialog in flutter

Question

Checkbox toggle within dialog not update real time???? when i have to onChanged then not update checkbox within Dialog

var is_checked = false;
    void updateCheckBox() {
      showGeneralDialog(
        pageBuilder: (context, _, __) {
          return new Row(
            children: <Widget>[
              new Checkbox(
                value: is_checked,
                onChanged: (bool value) {
                  this.setState((){
                  is_checked = !is_checked;
                  });
                },
              ),
              Text(
                '  Confirm bets before placing',
                style: TextStyle(
                    fontFamily:"Roboto",fontSize: 14.0, fontWeight: FontWeight.normal),
              )],
          );
        },
      );
    }

Solution

You need StatefulBuilder below pageBuilder and use is_checked = value;
You can copy paste run full code below

code snippet

showGeneralDialog(
      context: context,
      pageBuilder: (BuildContext buildContext, Animation<double> animation,
          Animation<double> secondaryAnimation) {
        return StatefulBuilder(
            builder: (BuildContext context, StateSetter setState) {
          return Wrap(
            children: <Widget>[
              Container(
                  width: 200.0,
                  height: 200.0,
                  color: Colors.orange,
                  child: Card(
                    child: Checkbox(
                      value: is_checked,
                      onChanged: (bool value) {
                        setState(() {
                          is_checked = value;
                        });
                      },
                    ),
                  )),
            ],
          );
        });
      },

working demo

full code

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;
  bool is_checked = false;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  void updateCheckBox() {
    showGeneralDialog(
      context: context,
      pageBuilder: (BuildContext buildContext, Animation<double> animation,
          Animation<double> secondaryAnimation) {
        return StatefulBuilder(
            builder: (BuildContext context, StateSetter setState) {
          return Wrap(
            children: <Widget>[
              Container(
                  width: 200.0,
                  height: 200.0,
                  color: Colors.orange,
                  child: Card(
                    child: Checkbox(
                      value: is_checked,
                      onChanged: (bool value) {
                        setState(() {
                          is_checked = value;
                        });
                      },
                    ),
                  )),
            ],
          );
        });
      },
      barrierDismissible: true,
      barrierLabel: MaterialLocalizations.of(context).modalBarrierDismissLabel,
      barrierColor: Colors.black,
      transitionDuration: const Duration(milliseconds: 200),
    );
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.display1,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: updateCheckBox,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

Comments

[Ravinder Kumar]

You should return stateful widget inside pageBuilder.

[Br Softech]

My friend working in widget but not working in Dialog... Not realtime Update in dialog.

[Br Softech]

By friend Awesome Answer.