AlertDialog 中的 TextFormField obscureText 不改变
TextFormField obscureText in AlertDialog don't change
我想在 AlertDialog 中更改 TextFormField 的 obscureText 模式，但它不起作用
点击 IconButton 没有改变
AlertDialog
中 TextFormField 的 obscureText
我想在 AlertDialog 中更改 TextFormField 的 obscureText 模式，但它不起作用
点击 IconButton 没有改变
AlertDialog
中 TextFormField 的 obscureText
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final username = TextEditingController(text: '');
final password = TextEditingController(text: '');
final formKey = GlobalKey<FormState>();
late bool obscure;
@override
void initState() {
obscure = true;
super.initState();
}
@override
void dispose() {
username.dispose();
password.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
actions: <Widget>[
IconButton(
onPressed: () {
showDialog(
context: context,
barrierDismissible: false,
builder: (_) {
return AlertDialog(
title: const Text('Connection'),
content: SizedBox(
height: 400,
width: 400,
child: Form(
key: formKey,
child: Column(
children: <Widget>[
TextFormField(
cursorColor: Colors.grey,
textInputAction: TextInputAction.next,
maxLines: 1,
controller: username,
validator: (value) {
return null;
},
decoration: const InputDecoration(
isDense: true,
prefixIcon: Icon(
Icons.person_outlined,
),
labelText: 'username',
),
),
const SizedBox(
height: 20.0,
),
TextFormField(
cursorColor: Colors.grey,
controller: password,
textInputAction: TextInputAction.next,
decoration: InputDecoration(
isDense: true,
prefixIcon: const Icon(Icons.key),
labelText: 'password',
suffixIcon: IconButton(
icon: const Icon(
Icons.remove_red_eye_outlined),
onPressed: () {
// CHAGE OBSCURE
setState(() {
obscure = !obscure;
if (kDebugMode) {
print(obscure); // OK
}
});
}),
),
obscureText: obscure, // NOT OK
obscuringCharacter: '*',
validator: (String? value) {
return null;
},
),
],
),
)),
actions: [
TextButton(
child: const Text('Send'),
onPressed: () {
if (formKey.currentState!.validate()) {
Navigator.of(context).pop();
}
},
),
],
);
});
},
icon: const Icon(Icons.person_outline_outlined),
),
],
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: const <Widget>[
Text(
'You have pushed the button this many times:',
),
],
),
),
);
}
}
为此，您必须使用 StatefulBuilder 在 Dialog 中使用 setState 并仅在其中更新 Widgets。
原因：setState 在 AlertDialog 中有不同的上下文，所以如果你想保持 AlertDialog 的状态，你必须使用 StatefulBuilder。它将为您的 AlertDialog
保持另一种状态
完整的工作代码：
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final username = TextEditingController(text: '');
final password = TextEditingController(text: '');
final formKey = GlobalKey<FormState>();
late bool obscure;
@override
void initState() {
obscure = true;
super.initState();
}
@override
void dispose() {
username.dispose();
password.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
actions: <Widget>[
IconButton(
onPressed: () {
showDialog(
context: context,
barrierDismissible: false,
builder: (_) {
return StatefulBuilder(
builder: (context, setState)
{
return AlertDialog(
title: const Text('Connection'),
content: SizedBox(
height: 400,
width: 400,
child: Form(
key: formKey,
child: Column(
children: <Widget>[
TextFormField(
cursorColor: Colors.grey,
textInputAction: TextInputAction.next,
maxLines: 1,
controller: username,
validator: (value) {
return null;
},
decoration: const InputDecoration(
isDense: true,
prefixIcon: Icon(
Icons.person_outlined,
),
labelText: 'username',
),
),
const SizedBox(
height: 20.0,
),
TextFormField(
cursorColor: Colors.grey,
controller: password,
textInputAction: TextInputAction.next,
decoration: InputDecoration(
isDense: true,
prefixIcon: const Icon(Icons.key),
labelText: 'password',
suffixIcon: IconButton(
icon: const Icon(Icons.remove_red_eye_outlined),
onPressed: () {
// CHAGE OBSCURE
setState(() {
obscure = !obscure;
if (kDebugMode) {
print(obscure); // OK
}
});
}),
),
obscureText: obscure,
// NOT OK
obscuringCharacter: '*',
validator: (String? value) {
return null;
},
),
],
),
)),
actions: [
TextButton(
child: const Text('Send'),
onPressed: () {
if (formKey.currentState!.validate()) {
Navigator.of(context).pop();
}
},
),
],
);
});
});
},
icon: const Icon(Icons.person_outline_outlined),
),
],
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: const <Widget>[
Text(
'You have pushed the button this many times:',
),
],
),
),
);
}
}
我想在 AlertDialog 中更改 TextFormField 的 obscureText 模式，但它不起作用
点击 IconButton 没有改变 AlertDialog
中 TextFormField 的 obscureText我想在 AlertDialog 中更改 TextFormField 的 obscureText 模式，但它不起作用
点击 IconButton 没有改变 AlertDialog
中 TextFormField 的 obscureTextimport 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final username = TextEditingController(text: '');
final password = TextEditingController(text: '');
final formKey = GlobalKey<FormState>();
late bool obscure;
@override
void initState() {
obscure = true;
super.initState();
}
@override
void dispose() {
username.dispose();
password.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
actions: <Widget>[
IconButton(
onPressed: () {
showDialog(
context: context,
barrierDismissible: false,
builder: (_) {
return AlertDialog(
title: const Text('Connection'),
content: SizedBox(
height: 400,
width: 400,
child: Form(
key: formKey,
child: Column(
children: <Widget>[
TextFormField(
cursorColor: Colors.grey,
textInputAction: TextInputAction.next,
maxLines: 1,
controller: username,
validator: (value) {
return null;
},
decoration: const InputDecoration(
isDense: true,
prefixIcon: Icon(
Icons.person_outlined,
),
labelText: 'username',
),
),
const SizedBox(
height: 20.0,
),
TextFormField(
cursorColor: Colors.grey,
controller: password,
textInputAction: TextInputAction.next,
decoration: InputDecoration(
isDense: true,
prefixIcon: const Icon(Icons.key),
labelText: 'password',
suffixIcon: IconButton(
icon: const Icon(
Icons.remove_red_eye_outlined),
onPressed: () {
// CHAGE OBSCURE
setState(() {
obscure = !obscure;
if (kDebugMode) {
print(obscure); // OK
}
});
}),
),
obscureText: obscure, // NOT OK
obscuringCharacter: '*',
validator: (String? value) {
return null;
},
),
],
),
)),
actions: [
TextButton(
child: const Text('Send'),
onPressed: () {
if (formKey.currentState!.validate()) {
Navigator.of(context).pop();
}
},
),
],
);
});
},
icon: const Icon(Icons.person_outline_outlined),
),
],
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: const <Widget>[
Text(
'You have pushed the button this many times:',
),
],
),
),
);
}
}
为此，您必须使用 StatefulBuilder 在 Dialog 中使用 setState 并仅在其中更新 Widgets。
原因：setState 在 AlertDialog 中有不同的上下文，所以如果你想保持 AlertDialog 的状态，你必须使用 StatefulBuilder。它将为您的 AlertDialog
完整的工作代码：
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final username = TextEditingController(text: '');
final password = TextEditingController(text: '');
final formKey = GlobalKey<FormState>();
late bool obscure;
@override
void initState() {
obscure = true;
super.initState();
}
@override
void dispose() {
username.dispose();
password.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
actions: <Widget>[
IconButton(
onPressed: () {
showDialog(
context: context,
barrierDismissible: false,
builder: (_) {
return StatefulBuilder(
builder: (context, setState)
{
return AlertDialog(
title: const Text('Connection'),
content: SizedBox(
height: 400,
width: 400,
child: Form(
key: formKey,
child: Column(
children: <Widget>[
TextFormField(
cursorColor: Colors.grey,
textInputAction: TextInputAction.next,
maxLines: 1,
controller: username,
validator: (value) {
return null;
},
decoration: const InputDecoration(
isDense: true,
prefixIcon: Icon(
Icons.person_outlined,
),
labelText: 'username',
),
),
const SizedBox(
height: 20.0,
),
TextFormField(
cursorColor: Colors.grey,
controller: password,
textInputAction: TextInputAction.next,
decoration: InputDecoration(
isDense: true,
prefixIcon: const Icon(Icons.key),
labelText: 'password',
suffixIcon: IconButton(
icon: const Icon(Icons.remove_red_eye_outlined),
onPressed: () {
// CHAGE OBSCURE
setState(() {
obscure = !obscure;
if (kDebugMode) {
print(obscure); // OK
}
});
}),
),
obscureText: obscure,
// NOT OK
obscuringCharacter: '*',
validator: (String? value) {
return null;
},
),
],
),
)),
actions: [
TextButton(
child: const Text('Send'),
onPressed: () {
if (formKey.currentState!.validate()) {
Navigator.of(context).pop();
}
},
),
],
);
});
});
},
icon: const Icon(Icons.person_outline_outlined),
),
],
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: const <Widget>[
Text(
'You have pushed the button this many times:',
),
],
),
),
);
}
}