It is not accepted to change the value in the Dropdown in the bottom sheet? - flutter

Question

Flutter . It is not accepted to change the value in the Dropdown in the bottom sheet ?
I made all the changes and it didn't work !
Knowing that on a normal screen it works
please help me
class _AddPostState extends State<AddPost> {
List<DropdownMenuItem<String>> get itemse{
List<DropdownMenuItem<String>> menuItems = [
DropdownMenuItem(
value: '1',
child: Container(
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: const [
SizedBox(width: 15,),
Icon(Icons.lock_outline,size: 19,),
SizedBox(width: 10,),
Text('Only me'),
],
),
),
),
DropdownMenuItem(
value: '2',
child: Container(
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: const [
SizedBox(width: 15,),
Icon(Icons.group_rounded,size: 19,),
SizedBox(width: 10,),
Text('Friends'),
],
),
),
),
DropdownMenuItem(
value: '3',
child: Container(
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: const [
SizedBox(width: 15,),
Icon(Icons.public,size: 19,),
SizedBox(width: 10,),
Text('Public'),
],
),
),
),
];
return menuItems;
}
String? selectedValue = '1';
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
foregroundColor: Colors.black,
backgroundColor: Colors.white,
title: const Text('Add Post'),
),
body: Center(
child: ElevatedButton(
child: const Text('Open'),
onPressed: bottomSheet,
),
),
);
}
void bottomSheet(){
showCupertinoModalBottomSheet(
expand: true,
context: context,
backgroundColor: Colors.transparent,
builder: (context) =>Scaffold(
appBar: AppBar(backgroundColor: Colors.white,foregroundColor: Colors.black,),
body: Column(
children: [
DropdownButton(
value: selectedValue,
items: itemse,
onChanged: (y) {
setState(() {
selectedValue = y! as String;
});
},
)
],
),
),
);
}
}
Seven days, I searched for a solution to the problem and did not find the solution. Please help

Answer 1

From the code i see you are not using the StatefulBuilder which will rebuild the sheet and change your value. From the code that you provided i have just created and example for you which might help you.
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:modal_bottom_sheet/modal_bottom_sheet.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(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
List<DropdownMenuItem<String>> get itemse {
List<DropdownMenuItem<String>> menuItems = [
DropdownMenuItem(
value: '1',
child: Container(
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: const [
SizedBox(
width: 15,
),
Icon(
Icons.lock_outline,
size: 19,
),
SizedBox(
width: 10,
),
Text('Only me'),
],
),
),
),
DropdownMenuItem(
value: '2',
child: Container(
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: const [
SizedBox(
width: 15,
),
Icon(
Icons.group_rounded,
size: 19,
),
SizedBox(
width: 10,
),
Text('Friends'),
],
),
),
),
DropdownMenuItem(
value: '3',
child: Container(
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: const [
SizedBox(
width: 15,
),
Icon(
Icons.public,
size: 19,
),
SizedBox(
width: 10,
),
Text('Public'),
],
),
),
),
];
return menuItems;
}
String? selectedValue = '1';
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
foregroundColor: Colors.black,
backgroundColor: Colors.white,
title: const Text('Add Post'),
),
body: Center(
child: ElevatedButton(
child: const Text('Open'),
onPressed: bottomSheet,
),
),
);
}
void bottomSheet() {
showCupertinoModalBottomSheet(
expand: true,
context: context,
backgroundColor: Colors.transparent,
builder: (context) =>
StatefulBuilder(builder: (BuildContext context, StateSetter setState /*You can rename this!*/) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.white,
foregroundColor: Colors.black,
),
body: Column(
children: [
DropdownButton(
value: selectedValue,
items: itemse,
onChanged: (y) {
setState(() {
selectedValue = y! as String;
});
},
)
],
),
);
}),
);
}
}