【发布时间】：2021-06-09 20:17:18
【问题描述】：
我有一个小部件，我在其中使用提供程序，但我想在普通小部件中使用值，所以也许任何人都可以提供帮助。
这是我使用提供者的地方：
Widget _buildName(BuildContext context) {
return Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
'Full Name',
style: kLabelStyle3,
),
SizedBox(height: 10.0),
Container(
alignment: Alignment.centerLeft,
height: 50.0,
child: TextFormField(
initialValue: UserData.fullname;
validator: (val) => val.isEmpty ? 'Enter your Name' : null,
onChanged: (val) {
setState(() => _currentfullname = val);
},
style: TextStyle(
color: Colors.black,
fontFamily: 'OpenSans',
),
decoration: InputDecoration(
enabledBorder: OutlineInputBorder(
borderRadius: BorderRadius.circular(25.0),
borderSide: BorderSide(
color: Colors.black,
width: 2.0,
),
),
contentPadding: EdgeInsets.only(top: 14.0),
prefixIcon: Icon(
Icons.person,
color: Colors.black,
),
hintText: 'Enter your Name',
hintStyle: kHintTextStyle2,
),
),
),
],
);
}
@override
Widget build(BuildContext context) {
final user = Provider.of<Userr>(context);
return StreamBuilder<UserData>(
stream: DatbaseService(uid:user.uid).userData,
builder: (context, snapshot) {
if(snapshot.hasData){
UserData userData =snapshot.data;
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.transparent,
elevation: 0.0,
),
body: AnnotatedRegion<SystemUiOverlayStyle>(
value: SystemUiOverlayStyle.light,
child: GestureDetector(
onTap: () => FocusScope.of(context).unfocus(),
child: Form(
key: _formKey,
child: Stack(
children: <Widget>[
Container(
height: double.infinity,
child: SingleChildScrollView(
physics: AlwaysScrollableScrollPhysics(),
padding: EdgeInsets.symmetric(
horizontal: 40.0,
vertical: 10,
),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Center(
child: Stack(
children: [
Container(
width: 110,
height: 110,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(100),
image: DecorationImage(
fit: BoxFit.cover,
image: NetworkImage(
"https://images.pexels.com/photos/3307758/pexels-photo-3307758.jpeg?auto=compress&cs=tinysrgb&dpr=3&h=250",
))),
),
Positioned(
bottom: 0,
right: 0,
child: Container(
height: 35,
width: 35,
decoration: BoxDecoration(
shape: BoxShape.circle,
border: Border.all(
width: 4,
color: Theme.of(context)
.scaffoldBackgroundColor,
),
color: Colors.green,
),
child: Icon(
Icons.edit,
color: Colors.white,
),
)),
],
),
),
SizedBox(
height: 10,
),
Text(
'Mein Profil',
style: TextStyle(
color: Colors.black,
fontFamily: 'OpenSans',
fontSize: 20.0,
fontWeight: FontWeight.w600,
),
),
showAlert2(),
_buildEmailTF(),
SizedBox(
height: 30.0,
),
_buildName(),
SizedBox(
height: 30.0,
),
_builduserName(),
SizedBox(
height: 30.0,
),
_buildPasswordTF(),
SizedBox(height: 30,),
_buildPassword2TF(),
_buildUpdateDataButton(),
// _buildEmailform(),
],
),
),
)
],
),
),
),
),
);
}else{
return null;
}
}
);
}
}
class DatbaseService{
final String uid;
DatbaseService({this.uid});
//collection reference
final CollectionReference myprofilsettings = FirebaseFirestore.instance.collection('meinprofilsettings');
Future updateUserData(String user,String fullname,String password,String email)async{
return await myprofilsettings.doc(uid).set({
'username':user,
'fullname':fullname,
'passwort':password,
'email':email,
});
}
//profil list from snapshot
List<myprofil> _myprofillistFromSnapshot(QuerySnapshot snapshot){
return snapshot.docs.map((doc){
return myprofil(
user: doc.data()['user']??'',
fullname: doc.data()['fullname']??'',
email: doc.data()['email']??'',
passowrd: doc.data()['password']??'',
);
}).toList();
}
//userData from snapshot
UserData _userDataFromSnapshot(DocumentSnapshot snapshot){
return UserData(
uid: uid,
name: snapshot.data()['name'],
fullname: snapshot.data()['fullname'],
email: snapshot.data()['email'],
password: snapshot.data()['password'],
);
}
//get myprofilsettings stream
Stream<List<myprofil>> get settings{
return myprofilsettings.snapshots().map(_myprofillistFromSnapshot);
}
//get user doc stream
Stream<UserData> get userData{
return myprofilsettings.doc(uid).snapshots().map(_userDataFromSnapshot);
}
}
import 'package:flutter/cupertino.dart';
class Userr{
final String uid;
Userr({this.uid});
}
class UserData {
final String uid;
final String user;
final String fullname;
final String email;
final String passowrd;
UserData({this.uid,this.user,this.fullname,this.email,this.passowrd, name, password});
忽略这个：
因为颤振说 __it 看起来像它看起来你的帖子主要是代码；请添加更多细节。 ___
IM加入一些textdehpkfnwrfemrjfikerfoiwnfdoiwjefiojnweoidfjwiodjwiojdoijweiodjweiojdoiewjdijewoijdoejwdiojewiojdiowjedijweoidjiowediwjdoiwejdiowjdiojwoidjaldknjlncjnnc XY ,, Y，Y ,, Y，ykampkdnndendiowendiojweiopjdipqejkdpojkdposkqwpodkqopwkdopkqwopdskqopdkpoqwkdopqkwopdkqwpodkpoqkdpkqpodkpqkdpokdpo ======== Exception caught by widgets library =======================================================
The following assertion was thrown building StreamBuilder<UserData>(dirty, state: _StreamBuilderBaseState<UserData, AsyncSnapshot<UserData>>#c612d):
A build function returned null.
The offending widget is: StreamBuilder<UserData>
Build functions must never return null.
To return an empty space that causes the building widget to fill available room, return "Container()". To return an empty space that takes as little room as possible, return "Container(width: 0.0, height: 0.0)".
The relevant error-causing widget was:
StreamBuilder<UserData> file:///Users/name/StudioProjects/project/lib/seitenleiste/meinacount.dart:356:16
When the exception was thrown, this was the stack:
#0 debugWidgetBuilderValue.<anonymous closure> (package:flutter/src/widgets/debug.dart:305:7)
#1 debugWidgetBuilderValue (package:flutter/src/widgets/debug.dart:326:4)
#2 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4592:7)
#3 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4759:11)
#4 Element.rebuild (package:flutter/src/widgets/framework.dart:4281:5)
...
====================================================================================================
【问题讨论】：
-
没有 BuildContext 就不能使用 Provider。考虑改用riverpod.dev。我希望这个答案对您有所帮助，因为这个问题实际上还不够清楚。
-
嗯，你真的不能在我的代码上展示如何做到这一点......
标签： firebase flutter dart provider