Checkbox 更新复选框并从颤振对话框中返回值
我正在尝试将一些城市列表添加到带有复选框的对话框中，以便我需要实现多个单击项目。下面是我想做的Checkbox 更新复选框并从颤振对话框中返回值,checkbox,dart,dialog,flutter,Checkbox,Dart,Dialog,Flutter,我正在尝试将一些城市列表添加到带有复选框的对话框中，以便我需要实现多个单击项目。下面是我想做的 on按下from按钮调用Rest服务，成功后我只显示一个对话框 void showCityDialog(BuildContext context) { SimpleDialog dialog = new SimpleDialog( title: Row( mainAxisAlignment: MainAxisAlignment.spaceBetween,
on按下void showCityDialog(BuildContext context) {
SimpleDialog dialog = new SimpleDialog(
title: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
new Text(
"CITIES",
style: TextStyle(fontSize: 18.0, color: Colors.black),
textAlign: TextAlign.center,
),
new RaisedButton(
onPressed: () {print("clicked");},
color: Color(0xFFfab82b),
child: new Text(
"Done",
style: TextStyle(color: Colors.white),
),)],),
children: <Widget>[
Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
new Container(
constraints: BoxConstraints(maxHeight: 500.0),
child: ListView.builder(
scrollDirection: Axis.vertical,
itemCount: cityData.length,
itemBuilder: (context, position) {
return new CheckboxListTile(
value: checkboxValueCity,
onChanged: (bool value) {
setState(() {
checkboxValueCity = value;
});
},
activeColor: Color(0xFFfab82b),
dense: true,
title: Text(
cityData[position].city_name,
style: TextStyle(fontSize: 16.0, color: Colors.black),
),);},),),],)],);
showDialog(
context: context,
builder: (BuildContext context) {
return dialog;
});
}
void showCityDialog（构建上下文）{
SimpleDialog=新建SimpleDialog(
标题：世界其他地区(
mainAxisAlignment:mainAxisAlignment.spaceBetween，
儿童：[
新文本(
“城市”，
样式：TextStyle（字体大小：18.0，颜色：Colors.black），
textAlign:textAlign.center，
),
新升起的按钮(
按下：（）{打印（“单击”）；}，
颜色：颜色（0xFFfab82b），
儿童：新文本(
“完成”，
样式：TextStyle（颜色：Colors.white），
),)],),
儿童：[
纵队(
mainAxisAlignment:mainAxisAlignment.start，
crossAxisAlignment:crossAxisAlignment.start，
儿童：[
新容器(
约束：框约束（最大高度：500.0），
子项：ListView.builder(
滚动方向：轴垂直，
itemCount:cityData.length，
itemBuilder：（上下文、位置）{
返回新的CheckboxListTile(
值：checkboxValueCity，
一旦更改：（布尔值）{
设置状态（）{
checkboxValueCity=值；
});
},
activeColor:Color（0xFFfab82b），
是的，
标题：正文(
城市数据[位置]。城市名称，
样式：TextStyle（字体大小：16.0，颜色：Colors.black），
),);},),),],)],);
显示对话框(
上下文：上下文，
生成器：（BuildContext上下文）{
返回对话框；
});
}
checkboxValueCity但在我的代码中，复选框并不是每次点击都引用，而是当我关闭该复选框并再次打开它时，复选框被选中。那么，如何从互动程序中获得多次单击，以及如何从对话框中返回列表？您的对话框需要是一个
StatefulWidget列表更新父类中的成员变量。在SimpleDialog
或AlertDialog
中使用ListView.builder似乎也存在一些问题（在Flatter Github中搜索问题），因此我使用了一个普通的对话框
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Checkbox Dialog Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Checkbox Dialog Demo'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
bool checkboxValueCity = false;
List<String> allCities = ['Alpha', 'Beta', 'Gamma'];
List<String> selectedCities = [];
@override
Widget build(BuildContext context) {
return Scaffold(
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
onPressed: () {
showDialog(
context: context,
builder: (context) {
return _MyDialog(
cities: allCities,
selectedCities: selectedCities,
onSelectedCitiesListChanged: (cities) {
selectedCities = cities;
print(selectedCities);
});
});
}),
);
}
}
class _MyDialog extends StatefulWidget {
_MyDialog({
this.cities,
this.selectedCities,
this.onSelectedCitiesListChanged,
});
final List<String> cities;
final List<String> selectedCities;
final ValueChanged<List<String>> onSelectedCitiesListChanged;
@override
_MyDialogState createState() => _MyDialogState();
}
class _MyDialogState extends State<_MyDialog> {
List<String> _tempSelectedCities = [];
@override
void initState() {
_tempSelectedCities = widget.selectedCities;
super.initState();
}
@override
Widget build(BuildContext context) {
return Dialog(
child: Column(
children: <Widget>[
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Text(
'CITIES',
style: TextStyle(fontSize: 18.0, color: Colors.black),
textAlign: TextAlign.center,
),
RaisedButton(
onPressed: () {
Navigator.pop(context);
},
color: Color(0xFFfab82b),
child: Text(
'Done',
style: TextStyle(color: Colors.white),
),
),
],
),
Expanded(
child: ListView.builder(
itemCount: widget.cities.length,
itemBuilder: (BuildContext context, int index) {
final cityName = widget.cities[index];
return Container(
child: CheckboxListTile(
title: Text(cityName),
value: _tempSelectedCities.contains(cityName),
onChanged: (bool value) {
if (value) {
if (!_tempSelectedCities.contains(cityName)) {
setState(() {
_tempSelectedCities.add(cityName);
});
}
} else {
if (_tempSelectedCities.contains(cityName)) {
setState(() {
_tempSelectedCities.removeWhere(
(String city) => city == cityName);
});
}
}
widget
.onSelectedCitiesListChanged(_tempSelectedCities);
}),
);
}),
),
],
),
);
}
}
导入“包装：颤振/材料.省道”；
void main（）=>runApp（MyApp（））；
类MyApp扩展了无状态小部件{
@凌驾
小部件构建（构建上下文）{
返回材料PP(
标题：“颤振复选框对话框演示”，
主题：主题数据(
主样本：颜色。蓝色，
),
主页：MyHomePage（标题：“颤振复选框对话框演示”），
);
}
}
类MyHomePage扩展StatefulWidget{
MyHomePage（{Key，this.title}）：超级（Key:Key）；
最后的字符串标题；
@凌驾
_MyHomePageState createState（）=>\u MyHomePageState（）；
}
类_MyHomePageState扩展状态{
bool checkboxValueCity=false；
列出所有城市=['Alpha'，'Beta'，'Gamma']；
列出所选城市=[]；
@凌驾
小部件构建（构建上下文）{
返回脚手架(
浮动操作按钮：浮动操作按钮(
子：图标（Icons.add），
已按下：（）{
显示对话框(
上下文：上下文，
生成器：（上下文）{
返回我的对话框(
城市：所有城市，
选定城市：选定城市，
OnSelectedCities列表已更改：（城市）{
选定城市=城市；
打印（选定城市）；
});
});
}),
);
}
}
类_MyDialog扩展StatefulWidget{
_我的对话({
这个城市，
这是我选择的城市，
此.onSelectedCitiesList已更改，
});
最终名单城市；
最终选定城市名单；
所选城市的最终价值发生变化列表发生变化；
@凌驾
_MyDialogState createState（）=>\u MyDialogState（）；
}
类_MyDialogState扩展了状态{
列表_tempSelectedCities=[]；
@凌驾
void initState（）{
_tempSelectedCities=widget.selectedCities；
super.initState（）；
}
@凌驾
小部件构建（构建上下文）{
返回对话框(
子：列(
儿童：[
划船(
mainAxisAlignment:mainAxisAlignment.spaceBetween，
儿童：[
正文(
"城市",，
样式：TextStyle（字体大小：18.0，颜色：Colors.black），
textAlign:textAlign.center，
),
升起的按钮(
已按下：（）{
Navigator.pop（上下文）；
},
颜色：颜色（0xFFfab82b），
子：文本(
“完成”，
样式：TextStyle（颜色：Colors.white），
),
),
],
),
扩大(
子项：ListView.builder(
itemCount:widget.cities.length，
itemBuilder:（构建上下文，int索引）{
final cityName=widget.cities[index]；
返回容器(
子：CheckboxListTile(
标题：文本（城市名称），
值：_tempSelectedCities.contains（cityName），
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Checkbox Dialog Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Checkbox Dialog Demo'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
bool checkboxValueCity = false;
List<String> allCities = ['Alpha', 'Beta', 'Gamma'];
List<String> selectedCities = [];
List<String> selectedCitiesTemp = [];
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("App Bar"),
),
body: Center(
child: Column(
children: <Widget>[
_list(),
RaisedButton(
child: Text("Update From TMP List"),
onPressed: () {
setState(() {
selectedCities = selectedCitiesTemp;
});
},
)
],
),
),
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
onPressed: () {
showDialog(
context: context,
builder: (BuildContext context) {
return _MyDialog(
cities: allCities,
selectedCities: selectedCities,
onSelectedCitiesListChanged: (cities) {
setState(() {
selectedCitiesTemp = cities;
});
},
);
});
}),
);
}
Widget _list() {
List<Widget> list = [];
for(String item in selectedCities) {
list.add(ListTile(
title: Text(item),
));
}
return Column(
children: list
);
}
}
class _MyDialog extends StatefulWidget {
_MyDialog({
this.cities,
this.selectedCities,
this.onSelectedCitiesListChanged,
});
final List<String> cities;
final List<String> selectedCities;
final ValueChanged<List<String>> onSelectedCitiesListChanged;
@override
_MyDialogState createState() => _MyDialogState();
}
class _MyDialogState extends State<_MyDialog> {
List<String> _tempSelectedCities = [];
@override
void initState() {
_tempSelectedCities = widget.selectedCities;
super.initState();
}
@override
Widget build(BuildContext context) {
return Dialog(
child: Column(
children: <Widget>[
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Text(
'CITIES',
style: TextStyle(fontSize: 18.0, color: Colors.black),
textAlign: TextAlign.center,
),
],
),
Expanded(
child: ListView.builder(
itemCount: widget.cities.length,
itemBuilder: (BuildContext context, int index) {
final cityName = widget.cities[index];
return Container(
child: CheckboxListTile(
title: Text(cityName),
value: _tempSelectedCities.contains(cityName),
onChanged: (bool value) {
if (value) {
if (!_tempSelectedCities.contains(cityName)) {
setState(() {
_tempSelectedCities.add(cityName);
});
}
} else {
if (_tempSelectedCities.contains(cityName)) {
setState(() {
_tempSelectedCities.removeWhere(
(String city) => city == cityName);
});
}
}
widget.onSelectedCitiesListChanged(_tempSelectedCities);
}),
);
}),
),
],
),
);
}
}
void _showDialog() {
showDialog(
context: context,
builder: (context) {
return StatefulBuilder( // StatefulBuilder
builder: (context, setState) {
return AlertDialog(
actions: <Widget>[
Container(
width: 400,
child: Column(
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Text(
"Student Attendence",
style: TextStyle(fontSize: 20),
),
SizedBox(
height: 5,
),
Container(
height: 2,
color: Colors.black,
),
SizedBox(
height: 15,
),
CheckboxListTile(
value: user1,
title: Text("user1"),
onChanged: (value){
setState(() {
user1=value;
});
},
),
Divider(
height: 10,
),
CheckboxListTile(
value: user2,
title: Text("user2"),
onChanged: (value){
setState(() {
user2=value;
});
},
),
Divider(
height: 10,
),
CheckboxListTile(
value: user3,
title: Text("user3"),
onChanged: (value){
setState(() {
user3=value;
});
},
),
Divider(
height: 10,
),
CheckboxListTile(
value: user4,
title: Text("user4"),
onChanged: (value){
setState(() {
user4=value;
});
},
),
Divider(
height: 10,
),
SizedBox(
height: 5,
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Material(
elevation: 5.0,
color: Colors.blue[900],
child: MaterialButton(
padding: EdgeInsets.fromLTRB(
10.0, 5.0, 10.0, 5.0),
onPressed: () {},
child: Text("Save",
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.white,
fontSize: 15,
)),
),
),
Material(
elevation: 5.0,
color: Colors.blue[900],
child: MaterialButton(
padding: EdgeInsets.fromLTRB(
10.0, 5.0, 10.0, 5.0),
onPressed: () {
setState(() {
Navigator.of(context).pop();
});
},
child: Text("Cancel",
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.white,
fontSize: 15,
)),
),
),
Material(
elevation: 5.0,
color: Colors.blue[900],
child: MaterialButton(
padding: EdgeInsets.fromLTRB(
10.0, 5.0, 10.0, 5.0),
onPressed: () {},
child: Text("Select All",
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.white,
fontSize: 15,
)),
),
),
],
)
],
))
],
);
},
);
},
);
}