如何在下拉列表底部制作一个按钮

Question

to create the popup list i used dropdown_search

design example as I would like to see it

when I start searching through the elements of the list, a button for adding should pop up

or the button should be immediately when we start searching for the element

drop-down list

button bottom

I chose all possible methods in the library, but still I can't use it with the addition of a button

all code https://github.com/dimapichuev2000/test_dropdownbutton

main.dart

import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:dropdown_search/dropdown_search.dart';
import 'package:test_dropdownbutton/gym_model.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData().copyWith(
        primaryColor: Colors.amber,
        colorScheme: ThemeData().colorScheme.copyWith(
              primary: Colors.orange,
            ),
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
 
  final _multiKey = GlobalKey<DropdownSearchState<String>>();

  Widget _customDropDownExample(BuildContext context, GymModel? item) {
    if (item == null) {
      return const Text(
        "Выберите фитнесс центр",
        style:
            TextStyle(fontSize: 15, color: Color.fromRGBO(33, 33, 33, 0.6)),
      );
    }
    return Container(
      
      child: (item.avatar == "")
          ? ListTile(
              contentPadding: EdgeInsets.all(0),
              leading: const CircleAvatar(
                radius: 25,
                backgroundColor: Colors.white,
                backgroundImage: NetworkImage(
                    'https://img.icons8.com/ios/50/000000/gum-.png'),
              ),
              title: Text(item.gym),
              subtitle: Text(
                item.location,
              ),
            )
          : ListTile(
              contentPadding: const EdgeInsets.all(0),
              leading: CircleAvatar(
                radius: 25,
                backgroundImage: NetworkImage(item.avatar ?? ''),
              ),
              title: Text(item.gym),
              subtitle: Text(
                item.location,
              ),
            ),
    );
  }

  Widget _exitPopup(BuildContext context) {
    return Container(
      decoration: const BoxDecoration(
        borderRadius: BorderRadius.only(
          topLeft: Radius.circular(20),
          topRight: Radius.circular(20),
        ),
      ),
      padding: const EdgeInsets.only(top: 2),
      child: Row(
        mainAxisSize: MainAxisSize.max,
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [
          Container(
            margin: EdgeInsets.all(8),
            height: 30,
            width: 30,
          ),
          const Text(
            "Фитнесс центр",
            style: TextStyle(fontSize: 17, fontWeight: FontWeight.w500),
          ),
          IconButton(
            icon: Image.asset(
              'assets/button_X.png',
              width: 25,
              height: 25,
              fit: BoxFit.fill,
            ),
            iconSize: 25,
            onPressed: () {
              Navigator.of(context).pop();
            },
          )
        ],
      ),
    );
  }

  Widget _customPopupItemBuilderExample(
      BuildContext context, GymModel? item, bool isSelected) {
    return Container(
      decoration: !isSelected
          ? null
          : BoxDecoration(
              borderRadius: BorderRadius.circular(5),
              color: Colors.white,
            ),
      child: ListTile(
          selected: isSelected,
          title: Text(item?.gym ?? ''),
          subtitle: Text(item?.location ?? ''),
          leading: (item!.avatar == "")
              ? const CircleAvatar(
                  radius: 25,
                  backgroundColor: Colors.white,
                  backgroundImage: NetworkImage(
                      'https://img.icons8.com/ios/100/000000/gum-.png'),
                )
              : CircleAvatar(
                  radius: 25,
                  backgroundImage: NetworkImage(item.avatar ?? ''),
                )),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Key value Pair - DropdownButton'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          mainAxisSize: MainAxisSize.max,
          children: <Widget>[
            Container(
              margin: const EdgeInsets.symmetric(vertical: 10, horizontal: 10),

              child: SingleChildScrollView(
                child: DropdownSearch<GymModel>(
                  mode: Mode.BOTTOM_SHEET,
                  showSearchBox: true,
                  compareFn: (item, selectedItem) => item?.id == selectedItem?.id,
                  scrollbarProps:ScrollbarProps(
                    radius: Radius.circular(20),
                    thickness: 4,

              
                  ),
                  onFind: (String? filter) => getData(filter),
                  dropdownSearchDecoration: const InputDecoration(
                    filled: true,
                    fillColor: Color(0xFFE3E3E4),
                    hintText: "Выберите фитнесс центр",
              
                    border: OutlineInputBorder(
                      borderRadius: BorderRadius.only(
                        topLeft: Radius.circular(10),
                        topRight: Radius.circular(10),
                        bottomLeft: Radius.circular(10),
                        bottomRight: Radius.circular(10),
                      ),
                      borderSide: BorderSide(
                        width: 0,
                        style: BorderStyle.none,
                      ),
                    ),
                    contentPadding: EdgeInsets.fromLTRB(12, 3, 0, 0),
                  ),
                  popupSafeArea:
                      const PopupSafeAreaProps(top: true, bottom: true),
                  // labelText: "Выберите фитнесс центр ",
                  onChanged: (data) {
                    print(data);
                  },
                  maxHeight: 850,
                  dropdownBuilder: _customDropDownExample,
                  popupItemBuilder: _customPopupItemBuilderExample,
                  dropDownButton: Image.asset('assets/dropButton.png',
                      color: Color(0xFF79818A)),
                  popupTitle: _exitPopup(context),
                  popupShape: const RoundedRectangleBorder(
                    borderRadius: BorderRadius.only(
                      topLeft: Radius.circular(10),
                      topRight: Radius.circular(10),
                    ),
                  ),
                  searchFieldProps: TextFieldProps(
                    decoration: const InputDecoration(
                        prefixIcon: Icon(
                          Icons.search,
                        ),
                        filled: true,
                        fillColor: Color(0xFFE3E3E4),
                        border: OutlineInputBorder(
                          borderRadius: BorderRadius.only(
                            topLeft: Radius.circular(10),
                            topRight: Radius.circular(10),
                            bottomLeft: Radius.circular(10),
                            bottomRight: Radius.circular(10),
                          ),
                          borderSide: BorderSide(
                            width: 0,
                            style: BorderStyle.none,
                          ),
                        ),
                        contentPadding: EdgeInsets.fromLTRB(12, 12, 8,0),
                        // labelText: "Поиск",
                        hintText: "Поиск",
                        hintStyle: TextStyle(fontSize: 17)),
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Future<List<GymModel>> getData(filter) async {
    var response = await Dio().get(
      "https://my-json-server.typicode.com/dimapichuev2000/JSON_TEST/posts",
      queryParameters: {"filter": filter},
    );

    final data = response.data;
    if (data != null) {
      return GymModel.fromJsonList(data);
    }

    return [];
  }
}

gym_model.dart

class GymModel {
  final String id;
  final String location;
  final String gym;
  final String? avatar;

  GymModel(
      {required this.id,
      required this.location,
      required this.gym,
      this.avatar});

  factory GymModel.fromJson(Map<String, dynamic> json) {
    return GymModel(
      id: json["id"],
      location: json["location"],
      gym: json["gym"],
      avatar: json["avatar"],
    );
  }

  static List<GymModel> fromJsonList(List list) {
    return list.map((item) => GymModel.fromJson(item)).toList();
  }


  @override
  String toString() => gym;
}

pubspec.yaml

name: fitsupp_coach
description: A new Flutter project.

# The following line prevents the package from being accidentally published to
# pub.dev using `flutter pub publish`. This is preferred for private packages.
publish_to: 'none' # Remove this line if you wish to publish to pub.dev

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0+1

environment:
  sdk: ">=2.12.0 <3.0.0"

# Dependencies specify other packages that your package needs in order to work.
# To automatically upgrade your package dependencies to the latest versions
# consider running `flutter pub upgrade --major-versions`. Alternatively,
# dependencies can be manually updated by changing the version numbers below to
# the latest version available on pub.dev. To see which dependencies have newer
# versions available, run `flutter pub outdated`.
dependencies:
  flutter_localizations:
    sdk: flutter 
  flutter:
    sdk: flutter


  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^1.0.2
  pinput: ^1.2.2
  intl: ^0.17.0
  quiver: ^3.0.1+1
  firebase_auth: ^3.3.5
  firebase_core: ^1.11.0
  dropdown_search: ^2.0.1
  dio: ^4.0.4
  provider: ^6.0.2
  percent_indicator: ^4.0.0

dev_dependencies:
  flutter_test:
    sdk: flutter

  # The "flutter_lints" package below contains a set of recommended lints to
  # encourage good coding practices. The lint set provided by the package is
  # activated in the `analysis_options.yaml` file located at the root of your
  # package. See that file for information about deactivating specific lint
  # rules and activating additional ones.
  flutter_lints: ^1.0.0
  

# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec

# The following section is specific to Flutter.
flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  assets:
   - assets/images/
   - assets/images/DropDown/

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/assets-and-images/#resolution-aware.

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/assets-and-images/#from-packages

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  fonts:
    - family: SF Pro Display
      fonts:
        - asset: fontsassets/SFProDisplay/SFProDisplay-Light.ttf
        - asset: fontsassets/SFProDisplay/SFProDisplay-Medium.ttf
        - asset: fontsassets/SFProDisplay/SFProDisplay-Black.ttf
        - asset: fontsassets/SFProDisplay/SFProDisplay-Bold.ttf
        - asset: fontsassets/SFProDisplay/SFProDisplay-Heavy.ttf
        - asset: fontsassets/SFProDisplay/SFProDisplay-Regular.ttf
        - asset: fontsassets/SFProDisplay/SFProDisplay-Semibold.ttf
        - asset: fontsassets/SFProDisplay/SFProDisplay-Thin.ttf
        - asset: fontsassets/SFProDisplay/SFProDisplay-Ultralight.ttf
          style: normal
    - family: SF Pro Text
      fonts:
        - asset: fontsassets/SFProText/SF-Pro-Text-Light.otf
        - asset: fontsassets/SFProText/SF-Pro-Text-Medium.otf
        - asset: fontsassets/SFProText/SF-Pro-Text-Black.otf
        - asset: fontsassets/SFProText/SF-Pro-Text-Bold.otf
        - asset: fontsassets/SFProText/SF-Pro-Text-Heavy.otf
        - asset: fontsassets/SFProText/SF-Pro-Text-Regular.otf
        - asset: fontsassets/SFProText/SF-Pro-Text-Semibold.otf
        - asset: fontsassets/SFProText/SF-Pro-Text-Thin.otf
        - asset: fontsassets/SFProText/SF-Pro-Text-Ultralight.otf
          style: normal      
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/custom-fonts/#from-packages
flutter_intl:
  enabled: true

Answer 1

There are many ways you can do that but the easiest and the most elegant solution in my opinion is the following:

Column(
  children: [
    Flexible(
      child: ListView.builder(
        shrinkWrap: true,
        itemCount: 5,
        itemBuilder: (BuildContext context, int i) {
          return Text(i.toString());
        },
      ),
    ),
    ElevatedButton.icon(
        onPressed: null,
        icon: const Icon(Icons.abc),
        label: const Text('next')),
  ],
);

Start with a Column widget and then add ListView.builder and button of your choosing, I use ElevatedButton.icon , as it's children. Now set the shrinkWrap setting in ListView.builder to true and finally wrap it with Flexible widget.

Hope this helped.

Answer 2

OK, this may not be the most elegant solution, but it does the trick.

First create a Model for the button:

class BottomButton {
  final String? text;

  BottomButton({
    this.text,
  });
}

Then you are going to want to change all the output types from GymModel? to dynamic :

Widget _customDropDownExample(BuildContext context, dynamic item)

Widget _customPopupItemBuilderExample(
      BuildContext context, dynamic item, bool isSelected)

DropdownSearch<dynamic>

Future<List<dynamic>> getData(filter)

Now, in the _customDropDownExample function where you are checking if the item == null add another to see if item is !GymModel :

if (item == null || item is !GymModel) {
  return const Text(
    "Выберите фитнесс центр",
    style: TextStyle(fontSize: 15, color: Color.fromRGBO(33, 33, 33, 0.6)),
  );
}

Inside _customPopupItemBuilderExample function check to see if the item is GymModel if so then do exactly what you were doing before and if not then create a button widget of your choice, I used an ElevatedButton for simplicity:

if (item is GymModel) {
  return Container(
    decoration: !isSelected
        ? null
        : BoxDecoration(
            borderRadius: BorderRadius.circular(5),
            color: Colors.white,
          ),
    child: ListTile(
        selected: isSelected,
        title: Text(item.gym),
        subtitle: Text(item.location),
        leading: (item.avatar == "")
            ? const CircleAvatar(
                radius: 25,
                backgroundColor: Colors.white,
                backgroundImage: NetworkImage("https://picsum.photos/200"),
              )
            : CircleAvatar(
                radius: 25,
                backgroundImage: NetworkImage(item.avatar ?? ''),
              )),
  );
} else {
  return ElevatedButton(onPressed: () {}, child: Text(item.text));
}

Finally inside getData function where you check if the data != null add your button model ( BottomButton , in my case) to the list:

Future<List<dynamic>> getData(filter) async {
  var response = await Dio().get(
    "https://my-json-server.typicode.com/dimapichuev2000/JSON_TEST/posts",
    queryParameters: {"filter": filter},
  );

  final data = response.data;
  if (data != null) {
    List<dynamic> res = GymModel.fromJsonList(data);
    BottomButton button = BottomButton(text: "Good Luck!");
    return [...res, button];
  }
  return [];
}