本文介绍了似乎无法保存 TextField 的值以备将来使用的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
在我的登录屏幕上:要求用户输入登录名和密码.我将这些值保存在两个变量中:电子邮件和密码.然后用户必须点击一个按钮才能实际登录.问题是，由于某种原因(我真的无法弄清楚......)当用户点击按钮时，电子邮件和密码总是为空......
On my login screen : user is asked to type in login and password. I save these value in two variables : email and password. Then the user must tap a button to actually log in.The problem is that for some reason (that I really can't figure out...) email and password are always empty when user hits the button....
完整代码如下:
class SeConnecterScreen extends StatelessWidget {
static const String id = 'se_connecter_screen';
@override
Widget build(BuildContext context) {
var uD = Provider.of<UdProvider>(context);
String email = '';
String passWord = '';
final Connectivity _connectivity = Connectivity();
var scaffold = Scaffold(
extendBody: true,
extendBodyBehindAppBar: true,
backgroundColor: Colors.indigo[900],
body: Column(
children: [
Expanded(
flex: 4,
child: Container(
margin: const EdgeInsets.only(bottom: 12),
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage('images/start2.jpg'), fit: BoxFit.cover),
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(50),
),
),
height: MediaQuery.of(context).size.height / 4,
),
),
Expanded(
flex: 6,
child: Padding(
padding: const EdgeInsets.all(16.0),
child: Container(
height: MediaQuery.of(context).size.height -
(MediaQuery.of(context).size.height / 4),
padding: EdgeInsets.all(8.0),
decoration: BoxDecoration(
color: Colors.white,
border: Border.all(
width: 1.0,
color: Colors.white,
),
borderRadius: BorderRadius.circular(10.0),
),
child: SingleChildScrollView(
child: Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
children: [
Text(
'WORD CHAMPIONS',
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.indigo[900],
fontSize: 28.0,
fontWeight: FontWeight.bold),
),
SizedBox(
height: 50,
),
TextField(
keyboardType: TextInputType.emailAddress,
decoration: InputDecoration(
focusColor: Colors.white,
border: OutlineInputBorder(),
labelText: 'Tape ton adresse email'),
onChanged: (value) {
email = value;
print(email);
},
),
SizedBox(
height: 25.0,
),
TextField(
obscureText: true,
keyboardType: TextInputType.name,
decoration: InputDecoration(
focusColor: Colors.white,
border: OutlineInputBorder(),
labelText: 'Tape ton mot de passe'),
onChanged: (value) {
passWord = value;
print(passWord);
},
),
SizedBox(
height: 35.0,
),
ElevatedButton.icon(
label: Text('Se connecter'),
icon: Icon(Icons.library_add_check_rounded),
style: ElevatedButton.styleFrom(
minimumSize: Size(30, 45),
primary: Colors.green[800],
onPrimary: Colors.white,
),
onPressed: () async {
print('Email : $email');
print('passWord : $passWord');
if (await _connectivity.checkConnectivity() ==
ConnectivityResult.none) {
showDialog(
context: context,
builder: (ctx) => AlertDialog(
title: Text(
'Oups!',
style: TextStyle(fontSize: 22.0),
),
content: Text(
'Il faut te connecter à Internet !',
style: TextStyle(fontSize: 18.0),
),
actions: [
TextButton(
onPressed: () {
Navigator.pushReplacementNamed(
context, StartingScreen.id);
},
child: Text(
'OK',
style: TextStyle(fontSize: 18.0),
),
),
],
),
);
} else {
String accountVerif =
await uD.checkAccountId(email, passWord);
if (accountVerif == '') {
DialogBuilder(context).showLoadingIndicator(
text: 'Téléchargement des bases',
color: Colors.black45);
await uD.downLoadUserInfo(email);
DialogBuilder(context).hideOpenDialog();
Navigator.pushReplacementNamed(
context, ProfileScreen.id);
} else {
showDialog(
context: context,
builder: (ctx) => AlertDialog(
title: Text(
'Oups!',
style: TextStyle(fontSize: 22.0),
),
content: Text(
'Ce compte n\'existe pas, ou le mot de passe est incorrect.',
style: TextStyle(fontSize: 18.0),
),
actions: [
TextButton(
onPressed: () {
Navigator.pushReplacementNamed(
context, StartingScreen.id);
},
child: Text(
'OK',
style: TextStyle(fontSize: 18.0),
),
),
],
),
);
}
}
}),
],
),
),
),
),
)),
],
),
);
return scaffold;
}
}
推荐答案
请尝试在构建方法之外定义密码和电子邮件变量.它可能会解决问题.
Please Try to define you password and email variables outside build method. It may solve issue.
看到它对我有用，也许你应该这样做
See it works for me, May be you should do
- 停止执行
- 运行'flutter clean'
- 运行flutter pub get"
- 执行它
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