dropdown_menu.1.dart 1.52 KB
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// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/material.dart';

/// Flutter code sample for [DropdownMenu].

const List<String> list = <String>['One', 'Two', 'Three', 'Four'];

void main() => runApp(const DropdownMenuApp());

class DropdownMenuApp extends StatelessWidget {
  const DropdownMenuApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(useMaterial3:true),
      home: Scaffold(
        appBar: AppBar(title: const Text('DropdownMenu Sample')),
        body: const Center(
          child: DropdownMenuExample(),
        ),
      ),
    );
  }
}

class DropdownMenuExample extends StatefulWidget {
  const DropdownMenuExample({super.key});

  @override
  State<DropdownMenuExample> createState() => _DropdownMenuExampleState();
}

class _DropdownMenuExampleState extends State<DropdownMenuExample> {
  String dropdownValue = list.first;

  @override
  Widget build(BuildContext context) {
    return DropdownMenu<String>(
      initialSelection: list.first,
      onSelected: (String? value) {
        // This is called when the user selects an item.
        setState(() {
          dropdownValue = value!;
        });
      },
      dropdownMenuEntries: list.map<DropdownMenuEntry<String>>((String value) {
        return DropdownMenuEntry<String>(
          value: value,
          label: value
        );
      }).toList(),
    );
  }
}