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45033a29f9
Fixes [Add option to control whether the root DropdownMenu can be closed or not](https://github.com/flutter/flutter/issues/139269) This introduces `DropdownMenu.closeBehavior` to provide control over `DropdownMenu` can be closed in nested menus. ### Code sample <details> <summary>expand to view the code sample</summary> ```dart import 'package:flutter/material.dart'; void main() => runApp(const MyApp()); class MyApp extends StatefulWidget { const MyApp({super.key}); @override State<MyApp> createState() => _MyAppState(); } class _MyAppState extends State<MyApp> { String selectedValue = "1"; @override Widget build(BuildContext context) { return MaterialApp( debugShowCheckedModeBanner: false, home: Scaffold( body: Center( child: Row( mainAxisAlignment: MainAxisAlignment.spaceEvenly, children: [ Column( spacing: 16.0, mainAxisSize: MainAxisSize.min, children: [ const Text("DropdownMenuCloseBehavior.none"), MenuAnchor( menuChildren: <Widget>[ Padding( padding: const EdgeInsets.all(8.0), child: DropdownMenu( closeBehavior: DropdownMenuCloseBehavior.none, label: const Text('Menu'), initialSelection: selectedValue, onSelected: (String? value) { if (value != null) { setState(() { selectedValue = value; }); } }, dropdownMenuEntries: ["1", "2", "3"] .map( (it) => DropdownMenuEntry( value: it, label: it, ), ) .toList(), ), ) ], child: const Text('Open Menu'), builder: (context, controller, child) { return ElevatedButton( onPressed: () { controller.open(); }, child: child, ); }, ), ], ), Column( spacing: 16.0, mainAxisSize: MainAxisSize.min, children: [ const Text("DropdownMenuCloseBehavior.self"), MenuAnchor( menuChildren: <Widget>[ Padding( padding: const EdgeInsets.all(8.0), child: DropdownMenu( closeBehavior: DropdownMenuCloseBehavior.self, label: const Text('Menu'), initialSelection: selectedValue, onSelected: (String? value) { if (value != null) { setState(() { selectedValue = value; }); } }, dropdownMenuEntries: ["1", "2", "3"] .map( (it) => DropdownMenuEntry( value: it, label: it, ), ) .toList(), ), ) ], child: const Text('Open Menu'), builder: (context, controller, child) { return ElevatedButton( onPressed: () { controller.open(); }, child: child, ); }, ), ], ), Column( spacing: 16.0, mainAxisSize: MainAxisSize.min, children: [ const Text("DropdownMenuCloseBehavior.all"), MenuAnchor( menuChildren: <Widget>[ Padding( padding: const EdgeInsets.all(8.0), child: DropdownMenu( closeBehavior: DropdownMenuCloseBehavior.all, label: const Text('Menu'), initialSelection: selectedValue, onSelected: (String? value) { if (value != null) { setState(() { selectedValue = value; }); } }, dropdownMenuEntries: ["1", "2", "3"] .map( (it) => DropdownMenuEntry( value: it, label: it, ), ) .toList(), ), ) ], child: const Text('Open Menu'), builder: (context, controller, child) { return ElevatedButton( onPressed: () { controller.open(); }, child: child, ); }, ), ], ), ], ), ), ), ); } } ``` </details> ### Demo https://github.com/user-attachments/assets/1f79ea6e-c0c6-4dcf-8180-d9dcca1c22c5