[英]Flutter how to get user input using text form in show dialog?
我正在尝试让用户输入以使用显示对话框中的文本表单更改标题,但似乎 state 正在重建,只要键盘显示/关闭,我的代码之前工作,但是当我执行 flutter 升级到 v1.17它不再起作用了。 我已经被困在这里几天了,我不知道我的代码有什么问题或可能导致它的错误,我只能在调试中看到“getSelectedText on inactive InputConnection”和“mSecurityInputMethodService is null”控制台,请帮忙。
这是我的代码示例:
import 'package:flutter/material.dart';
class Test extends StatefulWidget {
@override
_TestState createState() => _TestState();
}
class _TestState extends State<Test> {
final TextEditingController titleController = new TextEditingController();
final GlobalKey<FormState> _keyDialogForm = new GlobalKey<FormState>();
@override
void initState() {
super.initState();
titleController.text = 'Hello';
}
@override
Widget build(BuildContext context) {
return Scaffold(
resizeToAvoidBottomInset: false,
body: Center(
child: Column(
children: <Widget>[
Text(titleController.text),
SizedBox(
height: 50,
),
FlatButton(
color: Colors.redAccent,
onPressed: () {
showTitleDialog();
},
child: Text(
'Show Dialog',
style: TextStyle(
fontWeight: FontWeight.bold,
color: Colors.white,
),
))
],
),
));
}
Future showTitleDialog() {
return showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Form(
key: _keyDialogForm,
child: Column(
children: <Widget>[
TextFormField(
decoration: const InputDecoration(
icon: Icon(Icons.ac_unit),
),
maxLength: 8,
textAlign: TextAlign.center,
onSaved: (val) {
titleController.text = val;
},
autovalidate: true,
validator: (value) {
if (value.isEmpty) {
return 'Enter Title Name';
}
return null;
},
)
],
),
),
actions: <Widget>[
FlatButton(
onPressed: () {
if (_keyDialogForm.currentState.validate()) {
_keyDialogForm.currentState.save();
Navigator.pop(context);
}
},
child: Text('Save'),
color: Colors.blue,
),
FlatButton(
onPressed: () {
Navigator.pop(context);
},
child: Text('Cancel')),
],
);
});
}
}
您可以在下面复制粘贴运行完整代码
您可以在onSaved
中调用setState
代码片段
onSaved: (val) {
titleController.text = val;
setState(() {});
},
工作演示
完整代码
import 'package:flutter/material.dart';
class Test extends StatefulWidget {
@override
_TestState createState() => _TestState();
}
class _TestState extends State<Test> {
final TextEditingController titleController = new TextEditingController();
final GlobalKey<FormState> _keyDialogForm = new GlobalKey<FormState>();
@override
void initState() {
super.initState();
titleController.text = 'Hello';
}
@override
Widget build(BuildContext context) {
return Scaffold(
resizeToAvoidBottomInset: false,
body: Center(
child: Column(
children: <Widget>[
Text(titleController.text),
SizedBox(
height: 50,
),
FlatButton(
color: Colors.redAccent,
onPressed: () {
showTitleDialog();
},
child: Text(
'Show Dialog',
style: TextStyle(
fontWeight: FontWeight.bold,
color: Colors.white,
),
))
],
),
));
}
Future showTitleDialog() {
return showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Form(
key: _keyDialogForm,
child: Column(
children: <Widget>[
TextFormField(
decoration: const InputDecoration(
icon: Icon(Icons.ac_unit),
),
maxLength: 8,
textAlign: TextAlign.center,
onSaved: (val) {
titleController.text = val;
setState(() {});
},
autovalidate: true,
validator: (value) {
if (value.isEmpty) {
return 'Enter Title Name';
}
return null;
},
)
],
),
),
actions: <Widget>[
FlatButton(
onPressed: () {
if (_keyDialogForm.currentState.validate()) {
_keyDialogForm.currentState.save();
Navigator.pop(context);
}
},
child: Text('Save'),
color: Colors.blue,
),
FlatButton(
onPressed: () {
Navigator.pop(context);
},
child: Text('Cancel')),
],
);
});
}
}
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: Test(),
);
}
}
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