Flutter &引用'_listenerAttached';:“这不是真的”;在StatefulWidget中更改布局之后
我正试图根据一些Flutter &引用'_listenerAttached';:“这不是真的”;在StatefulWidget中更改布局之后,flutter,Flutter,我正试图根据一些TextFormField的焦点状态更改颤振屏幕的布局 我在以下代码中遇到问题: 当我聚焦触发布局更改的文本字段之一时,键盘隐藏 聚焦另一个文本字段时,我得到一个错误: 在生成\u ScrollableScope时抛出以下断言: “package:flatter/src/rendering/editable.dart”:失败的断言:第590行位置14: “_listenerAttached”:不正确。 我错过了什么 import 'package:flutter/mater
TextFormField
的焦点状态更改颤振屏幕的布局
我在以下代码中遇到问题:
- 当我聚焦触发布局更改的文本字段之一时,键盘隐藏
- 聚焦另一个文本字段时,我得到一个错误:
在生成\u ScrollableScope时抛出以下断言:
“package:flatter/src/rendering/editable.dart”:失败的断言:第590行位置14:
“_listenerAttached”:不正确。
我错过了什么
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Scaffold(
body: MyHomePage(),
));
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
bool _isCollapsed;
FocusNode _focusOne = FocusNode();
FocusNode _focusTwo = FocusNode();
TextEditingController _controllerOne = TextEditingController();
TextEditingController _controllerTwo = TextEditingController();
@override
void initState() {
super.initState();
_isCollapsed = false;
_focusOne.addListener(_onFocusChange);
_focusTwo.addListener(_onFocusChange);
}
@override
Widget build(BuildContext context) {
if (!_isCollapsed) {
return Center(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Text("Title"),
TextFormField(
focusNode: _focusOne,
controller: _controllerOne,
),
TextFormField(focusNode: _focusTwo, controller: _controllerTwo)
],
),
);
} else {
return Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
TextFormField(
focusNode: _focusOne,
controller: _controllerOne,
),
TextFormField(focusNode: _focusTwo, controller: _controllerTwo)
],
);
}
}
void _onFocusChange() {
setState(() {
if (_focusOne.hasFocus || _focusTwo.hasFocus) {
_isCollapsed = true;
} else {
_isCollapsed = false;
}
});
}
}
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{
//此小部件是应用程序的根。
@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,
),
家:脚手架(
正文:MyHomePage(),
));
}
}
类MyHomePage扩展StatefulWidget{
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
布尔!;
FocusNode_focusOne=FocusNode();
FocusNode_focusTwo=FocusNode();
TextEditingController _controllerOne=TextEditingController();
TextEditingController_controllerTwo=TextEditingController();
@凌驾
void initState(){
super.initState();
_isCollapsed=false;
_addListener(_onFocusChange);
_focusTwo.addListener(_onFocusChange);
}
@凌驾
小部件构建(构建上下文){
如果(!\u已合并){
返回中心(
子:列(
mainAxisSize:mainAxisSize.min,
儿童:[
正文(“标题”),
TextFormField(
focusNode:_focusOne,
控制员:_控制员,
),
TextFormField(focusNode:\u focusTwo,controller:\u controllerTwo)
],
),
);
}否则{
返回列(
mainAxisSize:mainAxisSize.min,
儿童:[
TextFormField(
focusNode:_focusOne,
控制员:_控制员,
),
TextFormField(focusNode:\u focusTwo,controller:\u controllerTwo)
],
);
}
}
void _onFocusChange(){
设置状态(){
if(_focusOne.hasFocus | | u focusTwo.hasFocus){
_isCollapsed=true;
}否则{
_isCollapsed=false;
}
});
}
}
似乎需要键
字段来跟踪布局更改之间的TextFormField。以下是一个可行的解决方案:
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Scaffold(
body: MyHomePage(),
));
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
bool _isCollapsed;
FocusNode _focusOne = FocusNode();
FocusNode _focusTwo = FocusNode();
TextEditingController _controllerOne = TextEditingController();
TextEditingController _controllerTwo = TextEditingController();
final GlobalKey<FormState> _formKeyOne = GlobalKey<FormState>();
final GlobalKey<FormState> _formKeyTwo = GlobalKey<FormState>();
@override
void initState() {
super.initState();
_isCollapsed = false;
_focusOne.addListener(_onFocusChange);
_focusTwo.addListener(_onFocusChange);
}
@override
Widget build(BuildContext context) {
if (!_isCollapsed) {
return Center(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Text("Title"),
TextFormField(
key: _formKeyOne,
focusNode: _focusOne,
controller: _controllerOne,
),
TextFormField(
key: _formKeyTwo,
focusNode: _focusTwo,
controller: _controllerTwo)
],
),
);
} else {
return Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
TextFormField(
key: _formKeyOne,
focusNode: _focusOne,
controller: _controllerOne,
),
TextFormField(
key: _formKeyTwo,
focusNode: _focusTwo,
controller: _controllerTwo)
],
);
}
}
void _onFocusChange() {
setState(() {
if (_focusOne.hasFocus || _focusTwo.hasFocus) {
_isCollapsed = true;
} else {
_isCollapsed = false;
}
});
}
}
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{
//此小部件是应用程序的根。
@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,
),
家:脚手架(
正文:MyHomePage(),
));
}
}
类MyHomePage扩展StatefulWidget{
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
布尔!;
FocusNode_focusOne=FocusNode();
FocusNode_focusTwo=FocusNode();
TextEditingController _controllerOne=TextEditingController();
TextEditingController_controllerTwo=TextEditingController();
最终的GlobalKey _formKeyOne=GlobalKey();
最终的GlobalKey _formKeyTwo=GlobalKey();
@凌驾
void initState(){
super.initState();
_isCollapsed=false;
_addListener(_onFocusChange);
_focusTwo.addListener(_onFocusChange);
}
@凌驾
小部件构建(构建上下文){
如果(!\u已合并){
返回中心(
子:列(
mainAxisSize:mainAxisSize.min,
儿童:[
正文(“标题”),
TextFormField(
钥匙:_formKeyOne,
focusNode:_focusOne,
控制员:_控制员,
),
TextFormField(
键:_formKeyTwo,
focusNode:_focusTwo,
控制器:_controllerTwo)
],
),
);
}否则{
返回列(
mainAxisSize:mainAxisSize.min,
儿童:[
TextFormField(
钥匙:_formKeyOne,
focusNode:_focusOne,
控制员:_控制员,
),
TextFormField(
键:_formKeyTwo,
focusNode:_focusTwo,
控制器:_controllerTwo)
],
);
}
}
void _onFocusChange(){
设置状态(){
if(_focusOne.hasFocus | | u focusTwo.hasFocus){
_isCollapsed=true;
}否则{
_isCollapsed=false;
}
});
}
}
似乎需要键
字段来跟踪布局更改之间的TextFormField。以下是一个可行的解决方案:
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Scaffold(
body: MyHomePage(),
));
}
}
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
bool _isCollapsed;
FocusNode _focusOne = FocusNode();
FocusNode _focusTwo = FocusNode();
TextEditingController _controllerOne = TextEditingController();
TextEditingController _controllerTwo = TextEditingController();
final GlobalKey<FormState> _formKeyOne = GlobalKey<FormState>();
final GlobalKey<FormState> _formKeyTwo = GlobalKey<FormState>();
@override
void initState() {
super.initState();
_isCollapsed = false;
_focusOne.addListener(_onFocusChange);
_focusTwo.addListener(_onFocusChange);
}
@override
Widget build(BuildContext context) {
if (!_isCollapsed) {
return Center(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Text("Title"),
TextFormField(
key: _formKeyOne,
focusNode: _focusOne,
controller: _controllerOne,
),
TextFormField(
key: _formKeyTwo,
focusNode: _focusTwo,
controller: _controllerTwo)
],
),
);
} else {
return Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
TextFormField(
key: _formKeyOne,
focusNode: _focusOne,
controller: _controllerOne,
),
TextFormField(
key: _formKeyTwo,
focusNode: _focusTwo,
controller: _controllerTwo)
],
);
}
}
void _onFocusChange() {
setState(() {
if (_focusOne.hasFocus || _focusTwo.hasFocus) {
_isCollapsed = true;
} else {
_isCollapsed = false;
}
});
}
}
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{
//此小部件是应用程序的根。
@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,
),
家:脚手架(
正文:MyHomePage(),
));
}
}
类MyHomePage扩展StatefulWidget{
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
布尔!;
FocusNode_focusOne=FocusNode();
FocusNode_focusTwo=FocusNode();
TextEditingController _controllerOne=TextEditingController();
TextEditingController_controllerTwo=TextEditingController();
最终的GlobalKey _formKeyOne=GlobalKey();
最终的GlobalKey _formKeyTwo=GlobalKey();
@凌驾
void initState(){
超级