Customized dropdown_button widget

OutlinedDropdownButton.dart

// ![](https://flutter.github.io/assets-for-api-docs/assets/material/dropdown_button.png)

import 'package:flutter/material.dart';

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

/// This Widget is the main application widget.
class MyApp extends StatelessWidget {
  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: Center(
          child: MyStatefulWidget(),
        ),
      ),
    );
  }
}

class MyStatefulWidget extends StatefulWidget {
  MyStatefulWidget({Key key}) : super(key: key);

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

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  @override
  Widget build(BuildContext context) {
    return Container(
      width: 326.0,
      padding: EdgeInsets.only(top: 0.0, right: 12.0, bottom: 0.0, left: 12.0),
      child: DropdownButton<String>(
        hint: Text('どの段階で中止しますか？ *'),
        icon: Icon(
          Icons.arrow_drop_down,
          color: Colors.grey[400],
        ),
        isExpanded: true,
        iconSize: 24,
        style: TextStyle(color: Colors.grey[900]),
        underline: Container(
          height: 0,
        ),
        onChanged: (String value) {},
        items: <String>['出発前', 'お店に向かう途中', 'お会計前', 'お届け先に向かう途中', 'お届け時']
            .map<DropdownMenuItem<String>>((String value) {
          return DropdownMenuItem<String>(
            value: value,
            child: Text(
              value,
            ),
          );
        }).toList(),
      ),
      decoration: ShapeDecoration(
        shape: RoundedRectangleBorder(
          side: BorderSide(
            width: 2.0,
            style: BorderStyle.solid,
            color: Colors.green[500],
          ),
          borderRadius: BorderRadius.all(Radius.circular(4.0)),
        ),
      ),
    );
  }
}