In my first page I have this:
onPressed: () {
Navigator.push(context,MaterialPageRoute(
builder: (context) =>
UpdateAttackScreen(
idAttack: idAttack,
title: title,
descriptionAttack:descriptionAttack,
indexSensations:indexSensations)));
},
in the second page where I want to receive this params:
class UpdateAttackScreen extends StatefulWidget {
final String idAttack;
final String title;
final String descriptionAttack;
final List<dynamic> indexSensations;
UpdateAttackScreen(
{Key key,
#required this.idAttack,
#required this.title,
#required this.descriptionAttack,
#required this.indexSensations})
: super(key: key);
#override
_UpdateAttackScreenState createState() => _UpdateAttackScreenState(idAttack, title, descriptionAttack, indexSensations);
}
class _UpdateAttackScreenState extends State<UpdateAttackScreen> {
String idAttack;
String title;
String descriptionAttack;
List<dynamic> indexSensations;
_UpdateAttackScreenState(idAttack, title, descriptionAttack, indexSensations);
TextEditingController _titleController = TextEditingController()..text = title;
TextEditingController _descriptionController = TextEditingController()..text = descriptionAttack;
The response error on title and descriptionAttack:
The instance member 'title' can't be accessed in an initializer.
Try replacing the reference to the instance member with a different expression
this code
TextEditingController _titleController = TextEditingController()..text = title;
TextEditingController _descriptionController = TextEditingController()..text = descriptionAttack;
replace with this
TextEditingController _titleController;
TextEditingController _descriptionController;
#override
void initState() {
super.initState();
_titleController = TextEditingController()..text = title;
_descriptionController = TextEditingController()..text = descriptionAttack;
}
Solution 1 :
Wrap _titleController with initState method
String title = '';
TextEditingController _titleController;
#override
void initState() {
_titleController..text = title;
super.initState();
}
Solution 2:
Transform the title variable into a static variable to be able to use it everywhere in your class
static String title = '';
TextEditingController _titleController = TextEditingController()..text = title ;
I fixed it!
class UpdateAttackScreen extends StatefulWidget {
final String idAttack;
final String title;
final String descriptionAttack;
final List<dynamic> indexSensations;
UpdateAttackScreen(
{Key key,
#required this.idAttack,
#required this.title,
#required this.descriptionAttack,
#required this.indexSensations})
: super(key: key);
#override
_UpdateAttackScreenState createState() => _UpdateAttackScreenState(idAttack, title, descriptionAttack, indexSensations);
}
class _UpdateAttackScreenState extends State<UpdateAttackScreen> {
String idAttack;
String title;
String descriptionAttack;
List<dynamic> indexSensations;
_UpdateAttackScreenState(idAttack, title, descriptionAttack, indexSensations);
TextEditingController _titleController;
TextEditingController _descriptionController;
Inside the TextFieldForm
initialValue: widget.title,
Related
how can i use forloop to generate values of data variable please help i am a beginner
class Mentions extends StatefulWidget {
const Mentions({
Key? key,
this.width,
this.height,
required this.fullname,
required this.username,
required this.photourl,
}) : super(key: key);
final double? width;
final double? height;
final List<String> fullname;
final List<String> username;
final List<String> photourl;
#override
_MentionsState createState() => _MentionsState();
}
class _MentionsState extends State<Mentions> {
List<Map<String, dynamic>> data = [];
void data1(
for(int i = 0; i< widget.fullname.length; i++) {
data.add({"Full Name": widget.fullname[i], "username": widget.username[i], "photourl" :widget.photourl[i] });
}
)
);
#override
Widget build(BuildContext context) {
return Container();
}
}
you can place your method inside initState
class _MentionsState extends State<Mentions> {
List<Map<String, dynamic>> data = [];
void data1 (){
for(int i = 0; i< widget.fullname.length; i++) {
data.add({
"Full Name": widget.fullname[i],
"username": widget.username[i],
"photourl" :widget.photourl[i]
});
}
)
}
#override
void initState() {
super.initState();
data1();
}
#override
Widget build(BuildContext context) {
return Container();
}
}
try this:
class Mentions extends StatefulWidget {
Mentions({
required this.fullname,
required this.username,
required this.photourl,
this.width,
this.height,
Key? key,
}) : super(key: key) {
for (var i = 0; i < fullname.length; i++) {
users.add({
'Full Name': fullname[i],
'username': username[i],
'photourl': photourl[i]
});
}
}
final double? width;
final double? height;
final List<String> fullname;
final List<String> username;
final List<String> photourl;
late final List<Map<String, dynamic>> users;
#override
_MentionsState createState() => _MentionsState();
}
class _MentionsState extends State<Mentions> {...}
then you can just use widget.users in _MentionsState. but you can even not set all this lists in widget constructor, do mapping to users before, and set to widget constructor just one list with users. and do you really need stateful widget instead of stateless?
Here is my problem when I add a new patient to my boxPatient everything is added with the constructor of my class Patient.
After creating a patient I would like to be able to add notes to him so add to the box of this patient with boxpatient.put(index, value)
However, when I add a new value with the Patient constructor it modifies all the other fields with null which is normal but I was wondering if there was a way to avoid modifying all the other fields and to modify only the listnote field
Here is the addition to my patient box of a new patient:
class PatientList extends StatefulWidget {
const PatientList({Key? key}) : super(key: key);
#override
State<PatientList> createState() => _PatientListState();
}
class _PatientListState extends State<PatientList> {
List<Patients> patientList = [];
late Box<Patients> boxPatient;
#override
void initState() {
super.initState();
boxPatient = Hive.box('Patient');
//boxPatient.clear();
print('Patient ${boxPatient.values}');
}
void _bottomnewpatient(BuildContext ctx) {
TextEditingController namecontroller = TextEditingController();
TextEditingController firstnamecontroller = TextEditingController();
TextEditingController dateofbirthcontroller = TextEditingController();
TextEditingController emailcontroller = TextEditingController();
TextEditingController phonenumbercontroller = TextEditingController();
void _submitData() {
final enteredname = namecontroller.text;
final enteredfirstname = firstnamecontroller.text;
final entereddateofbirth = dateofbirthcontroller.text;
final enteredemail = emailcontroller.text;
final enteredphonenumber = phonenumbercontroller.text;
if (enteredname.isEmpty ||
enteredfirstname.isEmpty ||
entereddateofbirth.isEmpty ||
enteredemail.isEmpty ||
enteredphonenumber.isEmpty) {
print('No input');
return;
}
final newPT = Patients(
name: enteredname,
firstname: enteredfirstname,
dateofbirth: entereddateofbirth,
email: enteredemail,
numero: enteredphonenumber,
date: DateTime.now(),
id: DateTime.now().millisecondsSinceEpoch,
//id: DateTime.now().millisecondsSinceEpoch,
//listOfNotes: [],
);
boxPatient.add(newPT);
Navigator.of(context).pop();
}
And here is the addition of a new note to the patient box pointed by the index:
The problem here is that I call my constructor Patients() so it rebuilds all my fields how to avoid that.
With this builder also don't have the possibility to add more notes as it rebuilds each time.
class InformationPatient extends StatefulWidget {
final Patients patients;
final int index;
const InformationPatient(this.patients, this.index, {Key? key})
: super(key: key);
#override
State<InformationPatient> createState() => _InformationPatientState();
}
class _InformationPatientState extends State<InformationPatient> {
late Box<Patients> boxPatient;
#override
void initState() {
super.initState();
boxPatient = Hive.box('Patient');
}
void _addNote(String newtitle, String newnote, String newconclusion) {
final newNOTE = Patients(
listOfNotes: [
ListNote(title: newtitle, note: newnote, conclusion: newconclusion)
],
);
boxPatient.put(widget.index, newNOTE);
Navigator.of(context).pop();
}
and here is the class model:
import 'package:hive_flutter/hive_flutter.dart';
part 'listpatient.g.dart';
#HiveType(typeId: 0)
class Patients {
#HiveField(0)
final String? name;
#HiveField(1)
final String? firstname;
#HiveField(3)
final String? dateofbirth;
#HiveField(4)
final String? email;
#HiveField(5)
final String? numero;
#HiveField(6)
final DateTime? date;
#HiveField(7)
final int? id;
#HiveField(8)
final List<ListNote>? listOfNotes;
const Patients({
this.name,
this.firstname,
this.dateofbirth,
this.email,
this.numero,
this.date,
this.id,
this.listOfNotes,
});
}
#HiveType(typeId: 10)
class ListNote {
#HiveField(1)
final String? title;
#HiveField(2)
final String? note;
#HiveField(3)
final String? conclusion;
ListNote({
this.title,
this.note,
this.conclusion,
});
}
Thank you very much for your help! :)
I have a similar widget for CupertinoPicker, but it was made by hand. I need to make the middle element of the list be selected by default, not the initial one as it is now. I've tried different options but haven't been able to do it yet. Please tell me how to implement this, I will be grateful for the help?
widget
class WheelSpeedPicker extends StatefulWidget {
final Function(dynamic) onValueChanged;
final int? startPosition;
final double itemSize;
final double? listHeight;
final int currentPosition;
final double? listWidth;
final FixedExtentScrollController? controller;
const WheelSpeedPicker({
Key? key,
required this.onValueChanged,
required this.currentPosition,
required this.itemSize,
this.startPosition,
this.listHeight,
this.controller,
this.listWidth,
}) : super(key: key);
#override
_WheelTimePickerState createState() {
return _WheelTimePickerState();
}
}
class _WheelTimePickerState extends State<WheelSpeedPicker> {
FixedExtentScrollController? fixedExtentScrollController;
int? currentPosition;
#override
void initState() {
super.initState();
currentPosition = widget.currentPosition;
fixedExtentScrollController = widget.controller ??
FixedExtentScrollController(initialItem: currentPosition ?? 0);
}
void _listener(int position) {
setState(() {
currentPosition = position;
});
widget.onValueChanged(currentPosition);
}
#override
void initState() {
super.initState();
// swap this
// currentPosition = widget.currentPosition;
// with this
currentPosition = (time.length / 2).floor();
fixedExtentScrollController = widget.controller ??
FixedExtentScrollController(initialItem: currentPosition ?? 0);
}
Other than that, I think your widget would be more useful if you added the items list to the widget parameters:
class WheelSpeedPicker extends StatefulWidget {
final Function(dynamic) onValueChanged;
final List<String> items;
final int? startPosition;
final double itemSize;
final double? listHeight;
final int currentPosition;
final double? listWidth;
final FixedExtentScrollController? controller;
const WheelSpeedPicker({
Key? key,
required this.items,
required this.onValueChanged,
required this.currentPosition,
required this.itemSize,
this.startPosition,
this.listHeight,
this.controller,
this.listWidth,
}) : super(key: key);
And then you'd have a more coherent set of parameters, because you already have a startPosition in the interface.
#override
void initState() {
super.initState();
currentPosition = widget.startPosition;
fixedExtentScrollController = widget.controller ??
FixedExtentScrollController(initialItem: startPosition ?? 0);
}
I have two files. File 1 has a nameController and file2 has emailController and passwordController.
I want to access the nameController from file1 in file2 which has the .registerUsingEmailPassword() method .
file1
class UserName extends StatefulWidget {
const UserName({Key? key}) : super(key: key);
#override
State<UserName> createState() => _UserNameState();
}
final _registerFormKey = GlobalKey<FormState>();
final _nameTextController = TextEditingController();
...
Form(
key: _registerFormKey,
child: TextFormField(
controller: _nameTextController,
..
));
}
file2
class SignUp extends StatefulWidget {
const SignUp({Key? key}) : super(key: key);
#override
State<SignUp> createState() => _SignUpState();
}
class _MyEmailState extends State<SignUp> {
final _regFormKey = GlobalKey<FormState>();
final _emailController = TextEditingController();
final _passwordController = TextEditingController();
...
if (_regFormKey.currentState!.validate()) {
User? user = await FireAuth.registerUsingEmailPassword(
name: _nameTextController.text, // I want to access this controller from
file1
email: _emailTextController.text,
password:_passwordTextController.text,
);
}
}
Can somebody help please.
You must be going from file 1 to file 2 through navigator, pass the data from nameController as an argument to the Navigator like,
Navigator.of(context).pushNamed('file2Route', arguments:nameController.text);
Get the text in file2 as
var nameText = ModalRoute.of(context)!.settings.arguments as String;
Then simply use the nameText in registerUsingEmailPassword() method.
If this is not the case, please do specify.
Cheers!!
class SignUp extends StatefulWidget {
final TextEditingController nameController; // pass via constructor
const SignUp({Key? key,required TextEditingController nameController}) : super(key: key);
#override
State<SignUp> createState() => _SignUpState();
}
then use in build like this
if (_regFormKey.currentState!.validate()) {
User? user = await FireAuth.registerUsingEmailPassword(
name: widget.nameController.text, // use like this
email: _emailTextController.text,
password:_passwordTextController.text,
);
class Notice extends StatefulWidget {
final String s_id;
const Notice({Key key, this.s_id}) : super(key: key);
#override
_NoticeState createState() => _NoticeState();
}
class _NoticeState extends State<Notice> {
TextEditingController _titleController = new TextEditingController();
var api =
Uri.parse('https://www.a2rstore.in/api/school/v1/noticeApi.php?id=${widget.s_id}');
You can't call the "widget" without the context.
The proper way to do it is by first defining your variable:
class _NoticeState extends State<Notice> {
TextEditingController _titleController = new TextEditingController();
var api;
...
}
And then assigning to it the value either in the build or initState method:
#override
initState(){
api = Uri.parse('https://www.a2rstore.in/api/school/v1/noticeApi.php?id=${widget.s_id}');
}