A StatefulWidget that Wraps a DropdownButtonFormField so that the selected value displays

dropdown_rating_form_field.dart

// (c) 2020 Yong Joseph Bakos. Use this freely.
// https://github.com/flutter/flutter/issues/27821
// Usage:
// DropdownRatingFormField(
//   maxRating: 4,
//   validator: (value) { /* ... */ },
//   onSaved: (value) { /* ... */ }
// );

import 'package:flutter/material.dart';

class DropdownRatingFormField extends StatefulWidget {

  final int maxRating;
  final void Function(dynamic) onSaved;
  final String Function(dynamic) validator;

  DropdownRatingFormField({Key key, this.maxRating, this.onSaved, this.validator}) : super(key: key);

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

class DropdownRatingFormFieldState extends State<DropdownRatingFormField> {

  int selectedValue;

  @override
  Widget build(BuildContext context) {
    return DropdownButtonFormField(
        value: selectedValue,
        items:  ratingMenuItems(maxRating: widget.maxRating),
        onChanged: (value) {
          setState( () => selectedValue = value );
        },
        decoration: InputDecoration(
          labelText: 'Rating',
          border: OutlineInputBorder()
        ),
        validator: widget.validator,
         onSaved: widget.onSaved
      );
  }

  List<DropdownMenuItem> ratingMenuItems({int maxRating}) {
    return List<DropdownMenuItem>.generate(maxRating, (i) {
      return DropdownMenuItem(value: i+1, child: Text('${i+1}'));
    });
  }

}

@JSeawell Yes! Thank you. I apparently did not post the gist from the latest commit. I've fixed it.

A little bit late now that the project is almost over - but if this code will be reused in future classes, set isDense in DropdownButtonFormField to true? Or else the height of this field will be larger than the two other fields in the form

@jonabantao Thanks for the suggestion!