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DropdownButtonFormField does not scale correctly to fit its parent's height #162350
Description
Steps to reproduce
Stretch a DropdownButtonFormField to fill its parent widget's height
Expected results
The UI should scale according to the widget height. This works when using DropdownButton instead of DropdownButtonFormFeild as shown in the screenshot, where the bottom border is moved lower to fill the remaining height.
Actual results
The actual visible elements including the border are only rendered at the top of the field instead of expanded to the full height. The widget scales to full height and is clickable across the whole height, but the border and decoration doesn't scale accordingly.
Code sample
DropdownButton UI scales to fit its parents hide, wheares DropdownButtonFormField does not
import 'package:flutter/material.dart';
void main() {
runApp(
MaterialApp(
home: const TestView(),
)
);
}
class TestView extends StatelessWidget {
const TestView({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
List<DropdownMenuItem<int>> debugItems = [
DropdownMenuItem(
value: 1,
child: Text("Option 1"),
),
DropdownMenuItem(
value: 2,
child: Text("Option 2"),
),
];
return Scaffold(
body: SizedBox(
height: 200,
child: Row(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
Expanded(
child: DropdownButton<int> ( // rendered correctly
isExpanded: true,
value: 1,
items: debugItems,
onChanged: (int? value) {},
),
),
Expanded(
child: DropdownButtonFormField<int>( // looks weird
isExpanded: true,
value: 1,
items: debugItems,
onChanged: (int? value) {},
),
),
],
),
),
);
}
}Screenshots or Video
DropdownButton on the left, DropdownButtonFormField on the right
Flutter Doctor output
Doctor output
[√] Flutter (Channel stable, 3.22.2, on Microsoft Windows [Version 10.0.19045.5247], locale de-DE)
• Flutter version 3.22.2 on channel stable at D:\Workspace\flutter
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision 761747bfc5 (8 months ago), 2024-06-05 22:15:13 +0200
• Engine revision edd8546116
• Dart version 3.4.3
• DevTools version 2.34.3
[√] Windows Version (Installed version of Windows is version 10 or higher)
[√] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
• Android SDK at D:\Workspace\Android\Sdk
• Platform android-34, build-tools 34.0.0
• Java binary at: D:\Programme\Android\Android Studio\jbr\bin\java
• Java version OpenJDK Runtime Environment (build 17.0.7+0-b2043.56-10550314)
• All Android licenses accepted.
[√] Chrome - develop for the web
• CHROME_EXECUTABLE = D:\Programme\Google\Chrome\Application\chrome.exe
[√] Visual Studio - develop Windows apps (Visual Studio Community 2022 17.10.5)
• Visual Studio at D:\Programme\Visual Studio\2022
• Visual Studio Community 2022 version 17.10.35122.118
• Windows 10 SDK version 10.0.22621.0
[√] Android Studio (version 2023.1)
• Android Studio at D:\Programme\Android\Android Studio
• Flutter plugin can be installed from:
https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 17.0.7+0-b2043.56-10550314)
[√] Connected device (3 available)
• Windows (desktop) • windows • windows-x64 • Microsoft Windows [Version 10.0.19045.5247]
• Chrome (web) • chrome • web-javascript • Google Chrome 132.0.6834.111
• Edge (web) • edge • web-javascript • Microsoft Edge 131.0.2903.146
[√] Network resources
• All expected network resources are available.
• No issues found!
Activity
darshankawar commentedon Jan 29, 2025
Thanks for the report. Seeing the same behavior on latest sdk versions and on all platforms.
[material_ui] Fix DropdownButtonFormField underline alignment at bott…
github-actions commentedon Oct 16, 2026
This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of
flutter doctor -vand a minimal reproduction of the issue.