Flutter 不能更改布尔值
isValidated值始终为false,当我写入正确的密码(1234)时变为true,但它会立即变为false。如果我输入了正确的密码,那么该值必须为true,否则必须为false 但是它不能正常工作 我创建了这个方法来创建我的应用程序验证,但我愿意接受任何建议Flutter 不能更改布尔值,flutter,dart,Flutter,Dart,isValidated值始终为false,当我写入正确的密码(1234)时变为true,但它会立即变为false。如果我输入了正确的密码,那么该值必须为true,否则必须为false 但是它不能正常工作 我创建了这个方法来创建我的应用程序验证,但我愿意接受任何建议 class Validation extends StatefulWidget { final bool isValidated; Validation({this.isValidated = false}); @over
class Validation extends StatefulWidget {
final bool isValidated;
Validation({this.isValidated = false});
@override
_ValidationState createState() => _ValidationState();
}
class _ValidationState extends State<Validation> {
bool _isValidated;
@override
void initState() {
super.initState();
_isValidated = widget.isValidated;
}
@override
Widget build(BuildContext context) {
Utils().init(context);
final screens = Utils.screen;
final _formKey = GlobalKey<FormState>();
final _passwordController = TextEditingController();
_validator() {
if (_passwordController.text != '1234') {
return Alert();
} else {
setState(() {
_isValidated = !_isValidated;
});
}
}
_textField() {
return SizedBox(
width: screens.width * 0.2,
height: screens.height * 0.08,
child: TextFormField(
controller: _passwordController,
textAlign: TextAlign.center,
decoration: InputDecoration(
filled: true,
fillColor: Colors.white,
contentPadding: EdgeInsets.all(0),
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(10),
),
),
),
);
}
_enterButton() {
return FlatButton(
color: Colors.white,
shape: OutlineInputBorder(
borderRadius: BorderRadius.circular(10),
),
child: Text(
'Entrar',
style: kSmallBlackButtonTextStyle,
),
onPressed: () {
_validator();
},
);
}
_validationForm() {
return Form(
key: _formKey,
autovalidate: false,
child: Column(
children: <Widget>[
_textField(),
DefaultDivider(0.03),
_enterButton(),
],
),
);
}
_blackPanel() {
return Center(
child: Container(
width: screens.width * 0.35,
height: screens.height * 0.4,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(20),
color: kBlackColor,
),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'Identificação para acessar Uber',
style: k20RegularTextStyle,
),
DefaultDivider(0.03),
Text(
'Senha',
style: k20MediumTextStyle,
),
DefaultDivider(0.02),
_validationForm(),
],
),
),
);
}
_notValidated() {
return Stack(
children: <Widget>[
BackdropFilter(
filter: ImageFilter.blur(sigmaX: 4, sigmaY: 4),
child: Container(color: kValidationBG),
),
_blackPanel(),
],
);
}
_validated() {
return Stack(children: [
Container(
width: screens.width * 0.001,
height: screens.height * 0.001,
),
]);
}
print('$_isValidated');
return _isValidated == false ? _notValidated() : _validated();
}
}
类验证扩展了StatefulWidget{
最终bool已验证;
验证({this.isValidated=false});
@凌驾
_ValidationState createState();
}
类_ValidationState扩展状态{
bool_是有效的;
@凌驾
void initState(){
super.initState();
_isValidated=widget.isValidated;
}
@凌驾
小部件构建(构建上下文){
Utils().init(上下文);
最终屏幕=Utils.screen;
final _formKey=GlobalKey();
final _passwordController=TextEditingController();
_验证器(){
如果(_passwordController.text!=“1234”){
返回警报();
}否则{
设置状态(){
_isValidated=!\u isValidated;
});
}
}
_textField(){
返回大小框(
宽度:屏幕宽度*0.2,
高度:1.5米*0.08米,
子项:TextFormField(
控制器:_passwordController,
textAlign:textAlign.center,
装饰:输入装饰(
是的,
fillColor:Colors.white,
contentPadding:EdgeInsets.all(0),
边框:大纲输入边框(
边界半径:边界半径。圆形(10),
),
),
),
);
}
_enterButton(){
返回按钮(
颜色:颜色,白色,
形状:OutlineInputBorder(
边界半径:边界半径。圆形(10),
),
子:文本(
“诱捕者”,
样式:ksmallbackbuttonextstyle,
),
已按下:(){
_验证器();
},
);
}
_validationForm(){
报税表(
键:_formKey,
自动验证:false,
子:列(
儿童:[
_textField(),
默认分隔符(0.03),
_enterButton(),
],
),
);
}
_黑屏(){
返回中心(
子:容器(
宽度:屏幕宽度*0.35,
高度:屏幕高度*0.4,
装饰:盒子装饰(
边界半径:边界半径。圆形(20),
颜色:kBlackColor,
),
子:列(
mainAxisAlignment:mainAxisAlignment.center,
儿童:[
正文(
"确定未来",,
样式:k20RegularTextStyle,
),
默认分隔符(0.03),
正文(
“Senha”,
样式:k20MediumTextStyle,
),
默认分隔符(0.02),
_validationForm(),
],
),
),
);
}
_notValidated(){
返回堆栈(
儿童:[
背投滤波器(
过滤器:ImageFilter.blur(sigmaX:4,sigmaY:4),
子项:容器(颜色:kValidationBG),
),
_blackPanel(),
],
);
}
_已验证(){
返回堆栈(子级:[
容器(
宽度:屏幕宽度*0.001,
高度:1.5米*0.001米,
),
]);
}
打印(“$”已验证);
返回_isValidated==false?_notValidated():_validated();
}
}
您可以复制粘贴运行下面的完整代码您需要移出
final\u passwordController=TextEditingController()代码>从生成
要避免在重新生成小部件时重置\u passwordController
final _formKey = GlobalKey<FormState>();
final _passwordController = TextEditingController();
@override
Widget build(BuildContext context) {
_validator() {
if (_passwordController.text != '1234') {
return Text("Alert()");
} else {
setState(() {
_isValidated = !_isValidated;
});
}
}
final_formKey=GlobalKey();
final _passwordController=TextEditingController();
@凌驾
小部件构建(构建上下文){
_验证器(){
如果(_passwordController.text!=“1234”){
返回文本(“警报()”);
}否则{
设置状态(){
_isValidated=!\u isValidated;
});
}
}
工作演示
完整测试代码
import 'package:flutter/material.dart';
import 'dart:ui';
class Validation extends StatefulWidget {
final bool isValidated;
Validation({this.isValidated = false});
@override
_ValidationState createState() => _ValidationState();
}
class _ValidationState extends State<Validation> {
bool _isValidated;
@override
void initState() {
super.initState();
_isValidated = widget.isValidated;
}
final _formKey = GlobalKey<FormState>();
final _passwordController = TextEditingController();
@override
Widget build(BuildContext context) {
_validator() {
if (_passwordController.text != '1234') {
return Text("Alert()");
} else {
setState(() {
_isValidated = !_isValidated;
});
}
}
_textField() {
return SizedBox(
width: MediaQuery.of(context).size.width * 0.2,
height: MediaQuery.of(context).size.height * 0.08,
child: TextFormField(
controller: _passwordController,
textAlign: TextAlign.center,
decoration: InputDecoration(
filled: true,
fillColor: Colors.white,
contentPadding: EdgeInsets.all(0),
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(10),
),
),
),
);
}
_enterButton() {
return FlatButton(
color: Colors.white,
shape: OutlineInputBorder(
borderRadius: BorderRadius.circular(10),
),
child: Text(
'Entrar',
//style: kSmallBlackButtonTextStyle,
),
onPressed: () {
_validator();
},
);
}
_validationForm() {
return Form(
key: _formKey,
autovalidate: false,
child: Column(
children: <Widget>[
_textField(),
Divider(),
_enterButton(),
],
),
);
}
_blackPanel() {
return Center(
child: Container(
width: MediaQuery.of(context).size.width * 0.35,
height: MediaQuery.of(context).size.height * 0.4,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(20),
//color: kBlackColor,
),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'Identificação para acessar Uber',
//style: k20RegularTextStyle,
),
Divider(),
Text(
'Senha',
//style: k20MediumTextStyle,
),
Divider(),
_validationForm(),
],
),
),
);
}
_notValidated() {
return Stack(
children: <Widget>[
BackdropFilter(
filter: ImageFilter.blur(sigmaX: 4, sigmaY: 4),
child: Container(),
),
_blackPanel(),
],
);
}
_validated() {
return Stack(children: [
Container(
child: Text("Validate")
),
]);
}
print('$_isValidated');
return _isValidated == false ? _notValidated() : _validated();
}
}
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>[
Validation(),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
导入“包装:颤振/材料.省道”;
导入“dart:ui”;
类验证扩展了StatefulWidget{
最终bool已验证;
验证({this.isValidated=false});
@凌驾
_ValidationState createState();
}
类_ValidationState扩展状态{
bool_是有效的;
@凌驾
void initState(){
super.initState();
_isValidated=widget.isValidated;
}
final _formKey=GlobalKey();
final _passwordController=TextEditingController();
@凌驾
小部件构建(构建上下文){
_验证器(){
如果(_passwordController.text!=“1234”){
返回文本(“警报()”);
}否则{
设置状态(){
_isValidated=!\u isValidated;
});
}
}
_textField(){
返回大小框(
宽度:MediaQuery.of(context).size.width*0.2,
高度:MediaQuery.of(上下文).size.height*0.08,
子项:TextFormField(
控制器:_passwordController,
textAlign:textAlign.center,
装饰:输入装饰(
是的,
fillColor:Colors.white,
contentPadding:EdgeInsets.all(0),
边框:大纲输入边框(
边界半径:边界半径。圆形(10),
),
),
),
);
}
_enterButton(){
返回按钮(
颜色:颜色,白色,
形状:OutlineInputBorder(
边界半径:边界半径。圆形(10),
),
子:文本(
“诱捕者”,
//样式:ksmallbackbuttonextstyle,
),
已按下:(){
_验证器();
},
);
}
_validationForm(){
报税表(
键:_formKey,
自动验证:false,
子:列(
C