Flutter - Radio Animation is not showing up on showDialog

Question

I\'m trying to create a Radio in a showDialog, however the animation that occurs on Radio does not appear in showDialog.<

Answer 1

Remember that components are immutable. When you call showDialog, the content of that dialog won't change even if HomePage does.

The solution is easy. You need to refactor a bit your code to something like :

    showDialog(
        context: context,
        builder: (context) => MyForm()
    )

and instead of changing the state of HomePage, you instead change the state of MyForm.

example :

class Test extends StatelessWidget {
  void onSubmit(String result) {
    print(result);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: RaisedButton(
          onPressed: () => showDialog(context: context, builder: (context) => MyForm(onSubmit: onSubmit)),
          child: Text("dialog"),
        ),
      ),
    );
  }
}

typedef void MyFormCallback(String result);

class MyForm extends StatefulWidget {
  final MyFormCallback onSubmit;

  MyForm({this.onSubmit});

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

class _MyFormState extends State<MyForm> {
  String value = "foo";

  @override
  Widget build(BuildContext context) {
    return SimpleDialog(
      title: Text("My form"),
      children: <Widget>[
        Radio(
          groupValue: value,
          onChanged: (value) => setState(() => this.value = value),
          value: "foo",
        ),
        Radio(
          groupValue: value,
          onChanged: (value) => setState(() => this.value = value),
          value: "bar",
        ),
        FlatButton(
          onPressed: () {
            Navigator.pop(context);
            widget.onSubmit(value);
          },
          child: new Text("submit"),
        )
      ],
    );
  }
}