我有一個代碼負責構建選單過濾器。它允許您按類別過濾資料，然后按子類別過濾資料。
最初，子類別處于關閉狀態，但是當您單擊箭頭時，它們可以打開。看一看
但我的問題是，如果我單擊任何類別的箭頭（在我的例子中是國家），那么所有子類別都會立即打開。看一看
這是我的代碼
class _FilterDialogUserState extends State<FilterDialogUser> {
Map<String, List<String>?> filters = {};
bool needRefresh = false;
bool isClickedCountry = false;
@override
void initState() {
super.initState();
filters = widget.initialState;
}
List<FilterItem> children = [
FilterItem('Georgia', subitems: [
FilterItem('Tbilisi'),
FilterItem('Batumi'),
]),
FilterItem('Poland', subitems: [
FilterItem('Warsaw'),
FilterItem('Krakow'),
FilterItem('Wroclaw'),
]),
FilterItem('Armenia', subitems: [
FilterItem('Erevan'),
FilterItem('Gyumri'),
]),
];
// Building a dialog box with filters.
@override
Widget build(BuildContext context) {
return SimpleDialog(
title: const Text('Filters',
textAlign: TextAlign.center,
style: TextStyle(
fontSize: 25,
fontFamily: 'SuisseIntl',
)),
contentPadding: const EdgeInsets.all(16),
// Defining parameters for filtering.
children: [
Column(
children: children.map(
(e) {
return Column(
children: [
InkWell(
onTap: () async {
setState(() {
isClickedCountry = !isClickedCountry;
});
},
child: Row(
children: [
Checkbox(
value: e.selected,
onChanged: (value) => setState(() {
e.subitems.forEach((element) =>
element.selected = value as bool);
e.selected = value as bool;
}),
),
Text(e.text),
const Spacer(),
isClickedCountry
? const Icon(Icons.arrow_circle_up)
: const Icon(Icons.arrow_circle_down)
],
),
),
if (e.subitems.isNotEmpty)
!isClickedCountry
? Container()
: Padding(
padding: const EdgeInsets.fromLTRB(30, 0, 0, 0),
child: Column(
children: e.subitems.map((e) {
return Row(children: [
Checkbox(
value: e.selected,
onChanged: (value) => setState(() {
e.selected = value as bool;
}),
),
Text(e.text),
]);
}).toList(),
),
)
],
);
},
).toList(),
),
]);
}
}
class FilterItem {
final String text;
bool selected;
List<FilterItem> subitems;
FilterItem(
this.text, {
this.selected = false,
this.subitems = const [],
});
}
告訴我，是否可以更改我的代碼，以便不打開所有子類別，而只打開用戶單擊的那個？
uj5u.com熱心網友回復：
每個主過濾器項必須一一控制。
- 定義串列 isClickedCountry 變數
- 從 List isClickedCountry 變數中保存和加載狀態
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
@override
void initState() {
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: _buildBody(),
floatingActionButton: FloatingActionButton(
onPressed: () {},
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
Widget _buildBody() {
return FilterDialogUser();
}
}
class FilterDialogUser extends StatefulWidget {
FilterDialogUser({Key key}) : super(key: key);
@override
State<FilterDialogUser> createState() => _FilterDialogUserState();
}
class _FilterDialogUserState extends State<FilterDialogUser> {
Map<String, List<String>> filters = {};
bool needRefresh = false;
List<bool> isClickedCountry = List.filled(3, false);
@override
void initState() {
super.initState();
// filters = widget.initialState;
}
List<FilterItem> children = [
FilterItem('Georgia', subitems: [
FilterItem('Tbilisi'),
FilterItem('Batumi'),
]),
FilterItem('Poland', subitems: [
FilterItem('Warsaw'),
FilterItem('Krakow'),
FilterItem('Wroclaw'),
]),
FilterItem('Armenia', subitems: [
FilterItem('Erevan'),
FilterItem('Gyumri'),
]),
];
// Building a dialog box with filters.
@override
Widget build(BuildContext context) {
return SimpleDialog(
title: const Text('Filters',
textAlign: TextAlign.center,
style: TextStyle(
fontSize: 25,
fontFamily: 'SuisseIntl',
)),
contentPadding: const EdgeInsets.all(16),
// Defining parameters for filtering.
children: [
Column(
children: children.map(
(e) {
final int index = children.indexOf(e);
return Column(
children: [
InkWell(
onTap: () async {
setState(() {
isClickedCountry[index] = !isClickedCountry[index];
});
},
child: Row(
children: [
Checkbox(
value: e.selected,
onChanged: (value) => setState(() {
e.subitems.forEach((element) =>
element.selected = value as bool);
e.selected = value as bool;
}),
),
Text(e.text),
const Spacer(),
isClickedCountry[index]
? const Icon(Icons.arrow_circle_up)
: const Icon(Icons.arrow_circle_down)
],
),
),
if (e.subitems.isNotEmpty)
!isClickedCountry[index]
? Container()
: Padding(
padding: const EdgeInsets.fromLTRB(30, 0, 0, 0),
child: Column(
children: e.subitems.map((e) {
return Row(children: [
Checkbox(
value: e.selected,
onChanged: (value) => setState(() {
e.selected = value as bool;
}),
),
Text(e.text),
]);
}).toList(),
),
)
],
);
},
).toList(),
),
]);
}
}
class FilterItem {
final String text;
bool selected;
List<FilterItem> subitems;
FilterItem(
this.text, {
this.selected = false,
this.subitems = const [],
});
}
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