Simple drop down example in flutter

dropdownexample.dart

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

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

class DropDownExample extends StatefulWidget {
  DropDownExample() : super();

  final String title = "DropDown Demo";

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

class Country {
  int id;
  String name;

  Country(this.id, this.name);

  static List<Country> getCountries() {
    return <Country>[
      Country(1, 'India'),
      Country(2, 'Malaysia'),
      Country(3, 'UAE'),
      Country(4, 'Indonesia'),
      Country(5, 'Nepal'),
    ];
  }
}

class DropDownExampleState extends State<DropDownExample> {
  //
  List<Country> _countries = Country.getCountries();
  List<DropdownMenuItem<Country>> _dropdownMenuItems;
  Country _selectedCountry;

  @override
  void initState() {
    _dropdownMenuItems = buildDropdownMenuItems(_countries);
    _selectedCountry = _dropdownMenuItems[0].value;
    super.initState();
  }

  List<DropdownMenuItem<Country>> buildDropdownMenuItems(List countries) {
    List<DropdownMenuItem<Country>> items = List();
    for (Country company in countries) {
      items.add(
        DropdownMenuItem(
          value: company,
          child: Text(
            company.name,
            style: TextStyle(fontWeight: FontWeight.bold, fontSize: 18),
          ),
        ),
      );
    }
    return items;
  }

  onChangeDropdownItem(Country selectedCompany) {
    setState(() {
      _selectedCountry = selectedCompany;
    });
  }

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      debugShowCheckedModeBanner: false,
      home: new Scaffold(
        appBar: new AppBar(
          title: new Text("DropDown Example"),
        ),
        body: new Container(
          child: Center(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.center,
              mainAxisAlignment: MainAxisAlignment.start,
              children: <Widget>[
                Align(
                  child: Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: Text(
                      "Select a Country",
                      style:
                          TextStyle(fontWeight: FontWeight.bold, fontSize: 18),
                    ),
                  ),
                  alignment: Alignment.topLeft,
                ),
                SizedBox(
                  height: 20.0,
                ),
                Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: DropdownButton(
                    value: _selectedCountry,
                    items: _dropdownMenuItems,
                    isExpanded: true,
                    underline: SizedBox(),
                    onChanged: onChangeDropdownItem,
/*                    hint: Text(
                      "Select a Country",
                      style:
                          TextStyle(fontWeight: FontWeight.bold, fontSize: 18),
                    ),*/ // you can set hint like that.
                  ),
                ),
                SizedBox(
                  height: 20.0,
                ),
                Text(
                  'Selected: ${_selectedCountry.name}',
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 15),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

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