我制作的表单存在问题，该表单保存了新创建的产品数据并将其添加到项目中。但是数据正在被删除！每当我切换tabs时，先前的TextFormField数据都会被删除。是否有可能将2个标签连接成1个？ eventho form在其上方，并带有key
这里缺少我的代码的外观：
import 'package:flutter/material.dart';
import 'package:google_fonts_arabic/fonts.dart';
import 'package:provider/provider.dart';
import '../add_ons/add_car.dart';
import '../providers/car_provider.dart';
import '../drawer/drawer.dart';
import '../screens/cars_screen.dart';
class CreateCar extends StatefulWidget {
static const routeName = '/create-car';
@override
_CreateCarState createState() => _CreateCarState();
}
class _CreateCarState extends State<CreateCar> {
final _nameNode = FocusNode();
final _cityNode = FocusNode();
final _countryNode = FocusNode();
final _currencyTNode = FocusNode();
final _priceNode = FocusNode();
final _categoryNode = FocusNode();
final _companyNode = FocusNode();
final _modelNode = FocusNode();
final _engineNode = FocusNode();
final _distanceCoveredNode = FocusNode();
final _transmissionNode = FocusNode();
final _oilTNode = FocusNode();
final _outColorNode = FocusNode();
final _inColorNode = FocusNode();
final _descriptionNode = FocusNode();
final _addressNode = FocusNode();
final _imageController = TextEditingController();
final _name = TextEditingController();
final _city = TextEditingController();
final _country = TextEditingController();
final _currencyT = TextEditingController();
final _price = TextEditingController();
final _category = TextEditingController();
final _engine = TextEditingController();
final _distance = TextEditingController();
final _transmission = TextEditingController();
final _oil = TextEditingController();
final _ocolor = TextEditingController();
final _icolor = TextEditingController();
final _description = TextEditingController();
final _address = TextEditingController();
final _company = TextEditingController();
@override
void dispose() {
_nameNode.dispose();
_cityNode.dispose();
_countryNode.dispose();
_currencyTNode.dispose();
_priceNode.dispose();
_categoryNode.dispose();
_companyNode.dispose();
_modelNode.dispose();
_engineNode.dispose();
_distanceCoveredNode.dispose();
_transmissionNode.dispose();
_oilTNode.dispose();
_outColorNode.dispose();
_inColorNode.dispose();
_descriptionNode.dispose();
_addressNode.dispose();
super.dispose();
}
final _form = GlobalKey<FormState>();
var _createdCar = AddCar(
id: null,
name: '',
city: '',
country: '',
currencyT: '',
price: '',
date: DateTime.now(),
sponsNum: '',
category: '',
company: '',
model: '',
year: 2019,
engine: '',
distanceCovered: 0.0,
transmission: '',
oilT: '',
outColor: '',
inColor: '',
description: '',
address: '',
image: '',
);
void _saveForm() {
final isValid = _form.currentState;
if (!isValid.validate()) {
print('enter correct data');
} else {
_form.currentState.save();
Provider.of<Cars>(context, listen: false).addCar(_createdCar);
Navigator.of(context).pushNamed(CarsScreen.routeName);
print('this works');
}
}
@override
Widget build(BuildContext context) {
return DefaultTabController(
length: 2,
initialIndex: 1,
child: Scaffold(
appBar: AppBar(
elevation: 15,
title: Row(
children: <Widget>[
Text(
'إضافة إعلان سيارة',
textAlign: TextAlign.center,
),
IconButton(
icon: Icon(Icons.save),
onPressed: _saveForm,
),
],
),
),
endDrawer: MyDrawer(),
body: Column(
children: <Widget>[
Container(
color: Theme.of(context).primaryColor,
child: TabBar(
indicator:
BoxDecoration(color: Color.fromRGBO(67, 45, 134, 1.0)),
isScrollable: true,
labelColor: Theme.of(context).accentColor,
unselectedLabelColor: Colors.white,
indicatorWeight: 0.1,
tabs: <Widget>[
Container(
width: MediaQuery.of(context).size.width * 0.5,
child: Tab(
child: Text(
'معلومات الإعلان',
style: TextStyle(
fontFamily: ArabicFonts.Tajawal,
package: 'google_fonts_arabic',
),
),
),
),
Container(
width: MediaQuery.of(context).size.width * 0.5,
child: Tab(
child: Text(
'معلومات السيارة',
style: TextStyle(
fontFamily: ArabicFonts.Tajawal,
package: 'google_fonts_arabic',
),
),
),
),
],
),
),
Expanded(
child: Form(
autovalidate: true,
key: _form,
child: TabBarView(
children: <Widget>[
ListView(
children: <Widget>[
Padding(
padding:
const EdgeInsets.only(right: 25.0, left: 25.0),
child: Column(
textDirection: TextDirection.rtl,
children: <Widget>[
Directionality(
textDirection: TextDirection.rtl,
child: TextFormField(
decoration: InputDecoration(
labelText: 'سعة المحرك',
),
focusNode: _engineNode,
onFieldSubmitted: (_) {
FocusScope.of(context)
.requestFocus(_distanceCoveredNode);
},
controller: _engine,
validator: (value) {
if (value.isEmpty) {
return 'Please provide a value.';
}
return null;
},
onSaved: (value) {
_createdCar = AddCar(
id: null,
name: _createdCar.name,
city: _createdCar.city,
country: _createdCar.country,
currencyT: _createdCar.currencyT,
price: _createdCar.price,
date: _createdCar.date,
sponsNum: _createdCar.sponsNum,
category: _createdCar.category,
company: _createdCar.company,
model: _createdCar.model,
year: _createdCar.year,
engine: value,
distanceCovered:
_createdCar.distanceCovered,
transmission: _createdCar.transmission,
oilT: _createdCar.oilT,
outColor: _createdCar.outColor,
inColor: _createdCar.inColor,
description: _createdCar.description,
address: _createdCar.address,
image: _createdCar.image);
},
),
),
//other data
],
),
),
],
),
ListView(
children: <Widget>[
Padding(
padding:
const EdgeInsets.only(right: 25.0, left: 25.0),
child: Column(
children: <Widget>[
Directionality(
textDirection: TextDirection.rtl,
child: TextFormField(
decoration: InputDecoration(
labelText: 'عنوان الإعلان',
),
validator: (value) {
if (value.isEmpty) {
return 'Please provide a value.';
}
return null;
},
controller: _name,
focusNode: _nameNode,
onFieldSubmitted: (_) {
FocusScope.of(context)
.requestFocus(_priceNode);
},
onSaved: (value) {
_createdCar = AddCar(
id: null,
name: value,
city: _createdCar.city,
country: _createdCar.country,
currencyT: _createdCar.currencyT,
price: _createdCar.price,
date: _createdCar.date,
sponsNum: _createdCar.sponsNum,
category: _createdCar.category,
company: _createdCar.company,
model: _createdCar.model,
year: _createdCar.year,
engine: _createdCar.engine,
distanceCovered:
_createdCar.distanceCovered,
transmission: _createdCar.transmission,
oilT: _createdCar.oilT,
outColor: _createdCar.outColor,
inColor: _createdCar.inColor,
description: _createdCar.description,
address: _createdCar.address,
image: _createdCar.image);
},
),
),
// other data
],
),
),
],
),
],
),
),
),
],
),
),
);
}
}
您必须使用AutomaticKeepAliveClientMixin来获得所需的输出。
以下示例清除您的想法。
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: Test(),
),
);
}
}
class Test extends StatefulWidget {
@override
_TestState createState() => _TestState();
}
class _TestState extends State<Test> {
@override
Widget build(BuildContext context) {
return DefaultTabController(
length: 2,
child: Scaffold(
appBar: AppBar(
title: Container(
child: Text('Dashboard'),
),
bottom: TabBar(
tabs: <Widget>[
Container(
padding: EdgeInsets.all(8.0),
child: Text('Deals'),
),
Container(
padding: EdgeInsets.all(8.0),
child: Text('Viewer'),
),
],
),
),
body: TabBarView(
children: <Widget>[
DealList(),
ViewersPage(),
],
),
),
);
}
}
class DealList extends StatefulWidget{
@override
_DealListState createState() => _DealListState();
}
class _DealListState extends State<DealList> with AutomaticKeepAliveClientMixin<DealList>{
@override
Widget build(BuildContext context) {
return Container(
child: TextFormField(
),
);
}
@override
// TODO: implement wantKeepAlive
bool get wantKeepAlive => true;
}
class ViewersPage extends StatefulWidget {
@override
_ViewersPageState createState() => _ViewersPageState();
}
class _ViewersPageState extends State<ViewersPage> with AutomaticKeepAliveClientMixin<ViewersPage>{
@override
Widget build(BuildContext context) {
return Container(
child: TextFormField(
),
);
}
@override
// TODO: implement wantKeepAlive
bool get wantKeepAlive => true;
}
更新：
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final _form = GlobalKey<FormState>();
final _name = TextEditingController();
final _city = TextEditingController();
String name,city;
@override
Widget build(BuildContext context) {
return Scaffold(
body: Form(
key: _form,
child: new Container(
child: Column(
children: <Widget>[
TextFormField(
decoration: InputDecoration(
labelText: 'سعة المحرك',
),
controller: _name,
validator: (value) {
if (value.isEmpty) {
return 'Please provide a value.';
}
return null;
},
onSaved: (value) {
name = _name.text.toString();
city = _city.text.toString();
print(city.toString());
},
),
TextFormField(
decoration: InputDecoration(
labelText: 'سعة المحرك',
),
controller: _city,
validator: (value) {
if (value.isEmpty) {
return 'Please provide a value.';
}
return null;
},
),
RaisedButton(
onPressed: (){
_form.currentState.save();
}
)
],
),
),
),
);
}
}