Flutter BoxConstraints强制在颤振中的AlertDialog中使用RadioListile时引发无限宽度异常
我试图显示一个Flutter BoxConstraints强制在颤振中的AlertDialog中使用RadioListile时引发无限宽度异常,flutter,dart,Flutter,Dart,我试图显示一个AlertDialog小部件,里面有2个radioistratile,但我得到一个渲染异常 以下是警报对话框的代码: enum_主题{亮,暗} 类ChangeThemeDialog扩展StatefulWidget{ @凌驾 _ChangeThemeDialogState createState()=>\u ChangeThemeDialogState(); } 类_changeMedialLogState扩展状态{ _Theme _Theme=_Theme.light; @凌驾 小
AlertDialog
小部件,里面有2个radioistratile
,但我得到一个渲染异常
以下是警报对话框的代码:
enum_主题{亮,暗}
类ChangeThemeDialog扩展StatefulWidget{
@凌驾
_ChangeThemeDialogState createState()=>\u ChangeThemeDialogState();
}
类_changeMedialLogState扩展状态{
_Theme _Theme=_Theme.light;
@凌驾
小部件构建(构建上下文){
返回警报对话框(
标题:文本(AppLocalizations.of(context).changeMetedialogTitle),
内容:文本(AppLocalizations.of(context).changeMetedialogContent),
行动:[
放射科医师(
标题:常量文本(“灯光”),
值:_Theme.light,
groupValue:_主题,
一旦更改:(\u主题值){
设置状态(){
_主题=价值;
});
},
),
放射科医师(
标题:常量文本(“黑色”),
值:_Theme.dark,
groupValue:_主题,
一旦更改:(\u主题值){
设置状态(){
_主题=价值;
});
},
),
],
);
}
}
以下是提出的例外情况:
════════ 呈现库捕获到异常═════════════════════════════════
在performLayout()期间引发了以下断言:
BoxConstraints强制无限宽。
以下函数向RenderParagraph的layout()函数提供了这些无效约束,该函数可能计算了所讨论的无效约束:
_RenderList.\u layoutBox(包:颤振/src/材料/列表\u-tile.省道:1318:9)
有问题的约束是:BoxConstraints(w=Infinity,0.0不要使用ActionDialog,只使用一个包含列的对话框
像这样
Widget build(BuildContext context) {
return Dialog(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
RadioListTile<String>(
title: const Text('Light'),
value: 'light',
// groupValue: _theme,
onChanged: null,
),
RadioListTile<String>(
title: const Text('Dark'),
value: 'dark',
// groupValue: _theme,
onChanged: null,
),
],
),
);
}
小部件构建(构建上下文){
返回对话框(
子:列(
mainAxisSize:mainAxisSize.min,
儿童:[
放射科医师(
标题:常量文本(“灯光”),
值:“轻”,
//groupValue:_主题,
onChanged:null,
),
放射科医师(
标题:常量文本(“黑色”),
值:'暗',
//groupValue:_主题,
onChanged:null,
),
],
),
);
}
不要使用ActionDialog,只使用内部有列的对话框
像这样
Widget build(BuildContext context) {
return Dialog(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
RadioListTile<String>(
title: const Text('Light'),
value: 'light',
// groupValue: _theme,
onChanged: null,
),
RadioListTile<String>(
title: const Text('Dark'),
value: 'dark',
// groupValue: _theme,
onChanged: null,
),
],
),
);
}
小部件构建(构建上下文){
返回对话框(
子:列(
mainAxisSize:mainAxisSize.min,
儿童:[
放射科医师(
标题:常量文本(“灯光”),
值:“轻”,
//groupValue:_主题,
onChanged:null,
),
放射科医师(
标题:常量文本(“黑色”),
值:'暗',
//groupValue:_主题,
onChanged:null,
),
],
),
);
}
您可以复制粘贴运行下面的完整代码
您可以使用Container
包装radiolistile
,并提供width
代码片段
Container(
width: 150,
child: RadioListTile<_Theme>(
容器(
宽度:150,
孩子:放射科医生(
工作演示
完整代码
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
enum _Theme { light, dark }
class ChangeThemeDialog extends StatefulWidget {
@override
_ChangeThemeDialogState createState() => _ChangeThemeDialogState();
}
class _ChangeThemeDialogState extends State<ChangeThemeDialog> {
_Theme _theme = _Theme.light;
@override
Widget build(BuildContext context) {
return AlertDialog(
title: Text("title"),
content: Text("content"),
actions: <Widget>[
Container(
width: 150,
child: RadioListTile<_Theme>(
title: const Text('Light'),
value: _Theme.light,
groupValue: _theme,
onChanged: (_Theme value) {
setState(() {
_theme = value;
});
},
),
),
Container(
width: 150,
child: RadioListTile<_Theme>(
title: const Text('Dark'),
value: _Theme.dark,
groupValue: _theme,
onChanged: (_Theme value) {
setState(() {
_theme = value;
});
},
),
)
],
);
}
}
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> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
ChangeThemeDialog(),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
import'包装:flift/cupertino.dart';
进口“包装:颤振/材料.省道”;
枚举主题{亮,暗}
类ChangeThemeDialog扩展StatefulWidget{
@凌驾
_ChangeThemeDialogState createState()=>\u ChangeThemeDialogState();
}
类_changeMedialLogState扩展状态{
_Theme _Theme=_Theme.light;
@凌驾
小部件构建(构建上下文){
返回警报对话框(
标题:文本(“标题”),
内容:文本(“内容”),
行动:[
容器(
宽度:150,
孩子:放射科医生(
标题:常量文本(“灯光”),
值:_Theme.light,
groupValue:_主题,
一旦更改:(\u主题值){
设置状态(){
_主题=价值;
});
},
),
),
容器(
宽度:150,
孩子:放射科医生(
标题:常量文本(“黑色”),
值:_Theme.dark,
groupValue:_主题,
一旦更改:(\u主题值){
设置状态(){
_主题=价值;
});
},
),
)
],
);
}
}
void main(){
runApp(MyApp());
}
类MyApp扩展了无状态小部件{
@凌驾
小部件构建(构建上下文){
返回材料PP(
标题:“颤振演示”,
主题:主题数据(
主样本:颜色。蓝色,
视觉密度:视觉密度。自适应平台密度,
),
主页:MyHomePage(标题:“颤振演示主页”),
);
}
}
类MyHomePage扩展StatefulWidget{
MyHomePage({Key,this.title}):超级(Key:Key);
最后的字符串标题;
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
int _计数器=0;
void _incrementCounter(){
设置状态(){
_计数器++;
});
}
@凌驾
小部件构建(构建上下文){
返回脚手架(
appBar:appBar(
标题:文本(widget.title),
),
正文:中(
子:列(
mainAxisAlignment:mainAxisAlignment.center,
儿童:[
changeMethedialog(),
正文(
“您已经按了这么多次按钮:”,
),
正文(
“$”计数器“,
风格:Theme.of(context).textTheme.headline4,
),
],
),
),
浮动操作按钮:浮动操作按钮(
按下时:\ u递增计数器,
工具提示:“增量”,
儿童: