setState() in onToggle()/use class variable to programmatically change toggle switch index

[jogee]

When doing a setState() in the onToggle() function, suddenly it doesn't switch to the other value anymore but no error is occurring. Even the state value is switching properly but the view doesn't get updated.

Everything works fine until I try to add some state, what am I doing wrong?

Best regards.

[PramodJoshi]

Hi @jogee , could you please provide runnable code and toggle_switch version you're currently using?

[jogee]

Using version 0.1.8

It also occurs with empty setState.

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:toggle_switch/toggle_switch.dart';

class App extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyScreen(),
    );
  }
}

class MyScreen extends StatefulWidget {
  @override
  _MyScreenState createState() => _MyScreenState();
}

class _MyScreenState extends State<MyScreen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        body: Container(
            margin: EdgeInsets.only(top: 30.0),
            child: ToggleSwitch(
                initialLabelIndex: 0,
                labels: ['one', 'two'],
                onToggle: (index) {
                  setState(() {});
                })));
  }
}

[PramodJoshi]

When you use static index, setState rebuilds and assigns same initialLabelIndex which in your case is '0'. You'll need to assign dynamic index to initialLabelIndex when using setState as shown below,

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

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

class App extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyScreen(),
    );
  }
}

class MyScreen extends StatefulWidget {
  @override
  _MyScreenState createState() => _MyScreenState();
}

class _MyScreenState extends State<MyScreen> {
  int initialLabelIndex = 0;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Container(
          margin: EdgeInsets.only(top: 30.0),
          child: ToggleSwitch(
            initialLabelIndex: initialLabelIndex,
            labels: ['one', 'two'],
            onToggle: (index) {
              print('switched index: $index');
              setState(
                () {
                  initialLabelIndex = index!;
                },
              );
            },
          ),
        ),
      ),
    );
  }
}

[jogee]

Ah that was the missing piece, many thanks!

[kcnypmek]

Is there a possibility to get 2 continuous rows of toggle switches?
If no,is there a possibility to disable initialIndex (no buttons selected at the start)?

[faiz-is]

on tap passing value index from list is that possible ?

[hillpates123]

how to set initial value ,
suppose we want to set second button active.

[PramodJoshi]

@hillpates123 code above shows exactly that. Just change int initialIndex to 1.