flutter radiovalue not changing - flutter

Question

I'm trying to get a very simple set of radiobuttons up, which is why it's so frustrating that they aren't working. I've tried setting this up in a similar class, and it's worked. I know for a fact that setstate is being called, but for some reason it's not updating the individual radio button. Which makes me think that this is some weird issue related to state.
Anyways, all help would be appreciated. My main class is the second part of the code below.
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import '../bloc/thembloc.dart';
import './components/textfield.dart';
class SignUp extends StatefulWidget {
#override
_SignUpState createState() => _SignUpState();
}
class _SignUpState extends State<SignUp> {
/*
ui for signup
includes multiple textfields.
includes all of the information that we'll need
to collect for an user to register an account.
todo: wrap everything in a form, encrypt it and send it to a private server.
*/
#override
Widget build(BuildContext context) {
double _height = MediaQuery.of(context).size.height;
double _width = MediaQuery.of(context).size.width;
final double _margin = 16.0;
final double _promptWidth = _width - 32.0;
final double _promptHeight = _height - 32.0;
final double _textFieldWidth = _promptWidth - 32.0;
int subscriberValue;
void switchSubscriber(int value) {
setState(() {
subscriberValue = value;
});
}
return BlocBuilder(
bloc: BlocProvider.of<ThemeBloc>(context),
builder: (context, ThemeState state) {
return Scaffold(
resizeToAvoidBottomInset: false,
resizeToAvoidBottomPadding: false,
appBar: AppBar(
centerTitle: true,
title: Text(
"smartmoney",
style: BlocProvider.of<ThemeBloc>(context).currentState.themedata.primaryTextTheme.display2,
),
// appbar
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(8.0),
bottomRight: Radius.circular(8.0))),
leading: IconButton(
icon: Icon(
Icons.arrow_back,
color: BlocProvider.of<ThemeBloc>(context).currentState.themedata.buttonColor,
),
onPressed: () {
print("going back");
},
),
backgroundColor: BlocProvider.of<ThemeBloc>(context).currentState.themedata.canvasColor,
),
body: Container(
height: _height,
width: _width,
color: BlocProvider.of<ThemeBloc>(context).currentState.themedata.backgroundColor,
child: Column(
children: <Widget>[
Padding(
padding: EdgeInsets.only(top: _margin),
child: Container(
decoration: BoxDecoration(
borderRadius: BorderRadius.all(Radius.circular(8.0)),
color: BlocProvider.of<ThemeBloc>(context).currentState.themedata.canvasColor,
boxShadow: [
BoxShadow(
spreadRadius: 0.0,
color: Colors.black38,
blurRadius: 6.0,
offset: Offset(0.0, 3.0)),
]),
width: _promptWidth,
height: _promptHeight - 48 - _margin,
child: Column(
children: <Widget>[
Text("Let's get started",
style: BlocProvider.of<ThemeBloc>(context).currentState.themedata.primaryTextTheme.display2,
),
Text("Enter your information to create an account",
style: BlocProvider.of<ThemeBloc>(context).currentState.themedata.primaryTextTheme.subtitle,
),
Padding(
padding: EdgeInsets.only(top: 8.0),
child: StyledTextField(
textFieldWidth: _textFieldWidth,
helperText: "First name",
),
),
Padding(
padding: EdgeInsets.only(top: 8.0),
child: StyledTextField(
textFieldWidth: _textFieldWidth,
helperText: "Last name",
),
),
Padding(
padding: EdgeInsets.only(top: 8.0),
child: StyledTextField(
textFieldWidth: _textFieldWidth,
helperText: "Email",
),
),
Padding(
padding: EdgeInsets.only(top: 8.0),
child: StyledTextField(
textFieldWidth: _textFieldWidth,
helperText: "Password",
),
),
Padding(
padding: EdgeInsets.only(top: 8.0),
child: StyledTextField(
textFieldWidth: _textFieldWidth,
helperText: "Phone number",
),
),
Text("Subscriber type",
style: BlocProvider.of<ThemeBloc>(context).currentState.themedata.primaryTextTheme.display1,
),
Radio(
groupValue: subscriberValue,
value: 0,
onChanged: (int value) => switchSubscriber(value),
),
Radio(
groupValue: subscriberValue,
value: 1,
onChanged: (int value) => switchSubscriber(value),
)
],
),
),
)
],
),
),
);
});
}
}
import 'package:flutter/material.dart';
import './bloc/thembloc.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'ui/signin.dart';
import 'ui/signup.dart';
import 'ui/onboarding.dart';
import './ui/testing/whatthefuck.dart';
void main() {
runApp(
MaterialApp(
home: SmartMoney(),
)
// SmartMoney()
);
}
class SmartMoney extends StatefulWidget {
#override
_SmartMoneyState createState() => _SmartMoneyState();
}
class _SmartMoneyState extends State<SmartMoney> {
final _themeBloc = ThemeBloc();
#override
Widget build(BuildContext context) {
return BlocProvider(
bloc: _themeBloc,
child: SignUp(),
);
}
}

Answer 1

The problem is because you defined your variable subscriberValue inside your build method. You're using setState calls that recall build method and in every recall of build you're losing the value of subscriberValue. I advise you to always use variables that will control the state of your widget as class members.
class _SignUpState extends State<SignUp> {
// HAS TO BE CLASS MEMBER AND IT'S GOOD AN INITIAL VALUE TOO..
int subscriberValue =1; // asuming that 1 is default radio button option
#override
Widget build(BuildContext context) {
//... some codes ...
//int subscriberValue; REMOVE THIS LINE. YOU'RE LOSING THE VALUE IN EVERY setState call
//You can define this method outside from build too.
void switchSubscriber(int value) {
setState(() {
subscriberValue = value;
});
}
}