How to make RadioListTile widget disabled in flutter

Question

I'm using the RadioListTile widget in my application and I want to disable changing the value after some condition is satisfied. and there is no isButtonDisabled prop just like in Radio widget. how can I disable this widget(stop the value from changing)?

By the time I was writing the above statement I figured it out and it was easy. so Ill post the question and will answer it below.

import 'package:flutter/material.dart';

class Body extends StatefulWidget {
  @override
  _BodyState createState() => _BodyState();
}

class _BodyState extends State<Body> {
  bool evaluate = false;
  int value;

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      mainAxisAlignment: MainAxisAlignment.start,
      children: [
        RadioListTile<int>(
          value: 0,
          isThreeLine: false,
          title: Text(
            'radio 1',
            style: TextStyle(
              fontWeight: FontWeight.bold,
            ),
          ),
          groupValue: value,
          onChanged: (value) => evaluate ? null : value = 0,
          activeColor: Colors.green,
        ),
        RadioListTile<int>(
          value: 1,
          isThreeLine: false,
          title: Text(
            'radio 2',
            style: TextStyle(
              fontWeight: FontWeight.bold,
            ),
          ),
          groupValue: value,
          onChanged: (value) => evaluate ? null : value = 1,
          activeColor: Colors.green,
        ),
        InkWell(
          onTap: () {
            evaluate = true;
          },
          child: Container(
            child: Center(
              child: Text(
                'Submit answer',
              ),
            ),
          ),
        )
      ],
    );
  }
}

score 14 · Accepted Answer · answered May 12 '21 at 10:53

Whenever onChange is null the component will become disabled. You should be able to do something link this instead:

onChanged: evaluate ? null : (value) => value = 0,

I would also rename evaluate to make it easier to understand, something like alreadyProvided, notAllowed, disabled or whatever makes sense, the most important thing is to really represent why it can't be changed.

In the end it could look like:

onChanged: alreadyProvided ? null : (value) => value = 0,

score 1 · Answer 2 · answered Jan 04 '21 at 08:51

I think you have already figured out the answer from the code. the solution is to declare bool value evaluate in my case then on button click make that value true and setstate with that value and on the onChanged prop of the RadioListTile add this code:

onChanged: (value) => evaluate ? null : value = 0,

hope this was helpful!

How to make RadioListTile widget disabled in flutter

2 Answers2

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