Trouble with flutter radio button

Question

I just want to have normal radio buttons where only one button in the group can be selected. According to tutorials online we need to set the groupvalue variable to the valu

Answer 1

Try this code

int _groupValue = -1;

@override
Widget build(BuildContext context) {
  return Column(
    children: <Widget>[
      _myRadioButton(
        title: "Checkbox 0",
        value: 0,
        onChanged: (newValue) => setState(() => _groupValue = newValue),
      ),
      _myRadioButton(
        title: "Checkbox 1",
        value: 1,
        onChanged: (newValue) => setState(() => _groupValue = newValue),
      ),
    ],
  );
}

Widget _myRadioButton({String title, int value, Function onChanged}) {
  return RadioListTile(
    value: value,
    groupValue: _groupValue,
    onChanged: onChanged,
    title: Text(title),
  );
}

Output:

Answer 2

Try this for horizontal radio button list:

int _groupValue = -1;

Container(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              mainAxisAlignment: MainAxisAlignment.start,
              children: <Widget>[
                Text('Gender', style: TextStyle(fontSize: 18)),
                Container(
                  child: Column(
                    children: <Widget>[
                      Row(
                        children: <Widget>[
                          Expanded(
                            flex: 1,
                            child: RadioListTile(
                              value: 0,
                              groupValue: _groupValue,
                              title: Text("Male"),
                              onChanged: (newValue) =>
                                  setState(() => _groupValue = newValue),
                              activeColor: Colors.red,
                              selected: false,
                            ),
                          ),
                          Expanded(
                            flex: 1,
                            child: RadioListTile(
                              value: 1,
                              groupValue: _groupValue,
                              title: Text("Female"),
                              onChanged: (newValue) =>
                                  setState(() => _groupValue = newValue),
                              activeColor: Colors.red,
                              selected: false,
                            ),
                          ),
                        ],
                      ),
                    ],
                  ),
                ),
              ],
            ),
          ),