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So I made a CRUD app with Firebase Firestore in Flutter. I have this error where it says
Exception caught by gesture
═══════════════════════
a document path must be a non-empty string
'package:cloud_firestore/src/collection_reference.dart':
package:cloud_firestore/src/collection_reference.dart:1
Failed assertion: line 116 pos 14: 'path.isNotEmpty'
I build this app with various tutorial videos in Youtube. I can make the Create, Read, and Delete features but I face this problem with Update features. Here's the code ...or check this Github https://github.com/rayhanyovi/Dapurku
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:intl/intl.dart';
import 'package:dapurkuu/warna.dart';
import 'package:dapurkuu/widget.dart';
Future main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(MyApp());
}
//=====================================
const Color Red = Color(0xFFDA4040);
const Color Blue = Color(0xFF5F52EE);
const Color Black = Color(0xFF3A3A3A);
const Color Grey = Color(0xFF717171);
const Color BGColor = Color(0xFFEEEFF5);
final controllerName = TextEditingController();
final controllerAge = TextEditingController();
final controllerBirthday = TextEditingController();
final updateName = TextEditingController();
final updateAge = TextEditingController();
final updateBirthday = TextEditingController();
//=====================================
class User {
String id;
final String name;
final int age;
final DateTime birthday;
User({
this.id = '',
required this.name,
required this.age,
required this.birthday,
});
Map<String, dynamic> toJson() => {
'id': id,
'name': name,
'age': age,
'birthday': birthday,
};
static User fromJson(Map<String, dynamic> json) => User(
id: json['id'],
name: json['name'],
age: json['age'],
birthday: (json['birthday'] as Timestamp).toDate(),
);
}
//=====================================
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
SystemChrome.setSystemUIOverlayStyle(
SystemUiOverlayStyle(statusBarColor: Colors.transparent));
return MaterialApp(
debugShowCheckedModeBanner: false,
title: "Test",
home: Home(),
);
}
}
//=====================================
class Home extends StatefulWidget {
#override
_HomeState createState() => _HomeState();
}
class _HomeState extends State<Home> {
final CollectionReference _users =
FirebaseFirestore.instance.collection('users');
#override
Widget build(BuildContext context) {
Future createUser(User user) async {
final docUser = FirebaseFirestore.instance.collection('users').doc();
user.id = docUser.id;
final json = user.toJson();
await docUser.set(json);
Future updateUser(User user) async {
final docUser = FirebaseFirestore.instance.collection('users').doc();
user.id = docUser.id;
final json = user.toJson();
await docUser.update(json);
}
}
Widget buildUser(User user) {
return Container(
margin: EdgeInsets.only(
right: 20,
left: 20,
bottom: 15,
),
child: Material(
child: ListTile(
onTap: () {
print("card");
},
contentPadding:
EdgeInsets.only(top: 10, bottom: 10, left: 20, right: 15),
shape:
RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
tileColor: Colors.white,
title: Padding(
padding: const EdgeInsets.only(bottom: 5),
child: Text(
user.name,
style: TextStyle(
fontSize: 18,
fontWeight: FontWeight.w600,
),
),
),
subtitle: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
'Jumlah: ${user.age}',
),
Text(
'Kadaluarsa: ${DateFormat('dd MMMM yyyy').format(user.birthday)}')
],
),
trailing: Wrap(spacing: 0, children: [
IconButton(
icon: Icon(Icons.edit),
iconSize: 24,
color: Colors.black,
onPressed: () async {
await Edit(context, createUser);
},
),
IconButton(
icon: Icon(Icons.delete),
iconSize: 24,
color: Colors.red,
onPressed: () {
final docUser = FirebaseFirestore.instance
.collection('users')
.doc(user.id);
docUser.delete();
},
),
]),
),
),
);
}
return Scaffold(
backgroundColor: BGColor,
appBar: _AppBar(),
body: Column(
children: [
/* JUDUL */
Column(
children: [
Container(
margin: EdgeInsets.only(left: 20),
alignment: Alignment.centerLeft,
child: SearchBox()),
Container(
margin: EdgeInsets.only(left: 20),
alignment: Alignment.centerLeft,
child: Text(
'Bahan Dapurmu',
style: TextStyle(
fontSize: 28,
fontWeight: FontWeight.bold,
color: Black,
),
),
)
],
),
/* STREAM BUILDER */
StreamBuilder(
stream: readUsers(),
builder: (context, snapshot) {
if (snapshot.hasData) {
final users = snapshot.data!;
return Expanded(
child: ListView(
scrollDirection: Axis.vertical,
shrinkWrap: true,
children: users.map(buildUser).toList(),
),
);
} else if (snapshot.hasError) {
return Container(
child: Text("data kosong"),
);
} else {
return Center(
child: CircularProgressIndicator(),
);
}
}),
],
),
floatingActionButton: FloatingActionButton(
onPressed: () async {
await Create(context, createUser);
},
child: Icon(Icons.add),
),
);
}
Edit(BuildContext context, Future<dynamic> updateUser(User user)) async {
showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text("Tambahkan bahan"),
content: Column(
children: [
TextField(
decoration: const InputDecoration(
labelText: 'Nama',
),
controller: updateName,
),
TextField(
decoration: const InputDecoration(
labelText: 'Umur',
),
controller: updateAge,
keyboardType: TextInputType.number,
),
TextField(
controller: updateBirthday,
//editing controller of this TextField
decoration: InputDecoration(
labelText: "Enter Date" //label text of field
),
readOnly: true,
//set it true, so that user will not able to edit text
onTap: () async {
DateTime? pickedDate = await showDatePicker(
context: context,
initialDate: DateTime.now(),
firstDate: DateTime(1950),
//DateTime.now() - not to allow to choose before today.
lastDate: DateTime(2100));
if (pickedDate != null) {
print(
pickedDate);
//pickedDate output format => 2021-03-10 00:00:00.000
//formatted date output using intl package => 2021-03-16
setState(() {
updateBirthday.text = pickedDate
.toString(); //set output date to TextField value.
});
} else {}
},
),
],
),
actions: <Widget>[
MaterialButton(
elevation: 5.0,
child: Text("Ubah Data"),
onPressed: () {
final user = User(
name: updateName.text,
age: int.parse(updateAge.text),
birthday: DateTime.parse(updateBirthday.text),
);
final docUser = FirebaseFirestore.instance
.collection('users')
.doc(user.id);
updateUser(user);
}),
],
);
});
}
Create(BuildContext context, Future<dynamic> createUser(User user)) async {
showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text("Tambahkan bahan"),
content: Column(
children: [
TextField(
decoration: const InputDecoration(
labelText: 'Nama',
),
controller: controllerName,
),
TextField(
decoration: const InputDecoration(
labelText: 'Umur',
),
controller: controllerAge,
keyboardType: TextInputType.number,
),
TextField(
controller: controllerBirthday,
//editing controller of this TextField
decoration: InputDecoration(
labelText: "Enter Date" //label text of field
),
readOnly: true,
//set it true, so that user will not able to edit text
onTap: () async {
DateTime? pickedDate = await showDatePicker(
context: context,
initialDate: DateTime.now(),
firstDate: DateTime(1950),
//DateTime.now() - not to allow to choose before today.
lastDate: DateTime(2100));
if (pickedDate != null) {
print(
pickedDate);
//pickedDate output format => 2021-03-10 00:00:00.000
//formatted date output using intl package => 2021-03-16
setState(() {
controllerBirthday.text = pickedDate
.toString(); //set output date to TextField value.
});
} else {}
},
),
],
),
actions: <Widget>[
MaterialButton(
elevation: 5.0,
child: Text("Tambahkan"),
onPressed: () {
final user = User(
name: controllerName.text,
age: int.parse(controllerAge.text),
birthday: DateTime.parse(controllerBirthday.text),
);
createUser(user);
}),
],
);
});
}
Stream<List<User>> readUsers() => FirebaseFirestore.instance
.collection('users')
.snapshots()
.map((snapshot) =>
snapshot.docs.map((doc) => User.fromJson(doc.data())).toList());
}
//=====================================
AppBar _AppBar() {
return AppBar(
elevation: 0,
backgroundColor: BGColor,
title: Center(
child: Text(
"Dapurku",
style: TextStyle(
fontSize: 20,
fontWeight: FontWeight.bold,
color: Black,
),
),
),
);
}
//=====================================
class UpdateButton extends StatelessWidget {
const UpdateButton({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return Container(
child: IconButton(
icon: Icon(Icons.edit),
iconSize: 24,
color: Colors.black,
onPressed: () {},
),
);
}
}
//=====================================
class SearchBox extends StatelessWidget {
const SearchBox({
Key? key,
}) : super(key: key);
#override
Widget build(BuildContext context) {
return Container(
padding: const EdgeInsets.only(left: 10),
child: const TextField(
decoration: InputDecoration(
contentPadding: EdgeInsets.all(0),
prefixIcon: Icon(
Icons.search,
color: Black,
size: 20,
),
prefixIconConstraints: BoxConstraints(
maxHeight: 20,
minWidth: 25,
),
border: InputBorder.none,
hintText: "Cari Bahan...",
hintStyle: TextStyle(
color: Grey,
)),
),
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(20),
),
);
}
}
Can you tell me what I did wrong or help me solve the problem? I've been looking for it anywhere and solving this problem for days. It is for my school assignment :/
import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
class NewTransaction extends StatefulWidget {
final Function addTx;
NewTransaction(this.addTx);
#override
_NewTransactionState createState() => _NewTransactionState();
}
class _NewTransactionState extends State<NewTransaction> {
final _titleController = TextEditingController();
final _amountController = TextEditingController();
DateTime _selectedDate;
void _submitData() {
if (_amountController.text.isEmpty) {
return;
}
final enteredTitle = _titleController.text;
final enteredAmount = double.parse(_amountController.text);
if (enteredTitle.isEmpty || enteredAmount <= 0 || _selectedDate == null) {
return;
}
widget.addTx(
enteredTitle,
enteredAmount,
_selectedDate,
);
Navigator.of(context).pop();
}
void _presentDatePicker() {
showDatePicker(
context: context,
initialDate: DateTime.now(),
firstDate: DateTime(2019),
lastDate: DateTime.now(),
).then((pickedDate) {
if (pickedDate == null) {
return;
}
setState(() {
_selectedDate = pickedDate;
});
});
print('...');
}
#override
Widget build(BuildContext context) {
return Card(
elevation: 5,
child: Container(
padding: EdgeInsets.all(10),
child: Column(
crossAxisAlignment: CrossAxisAlignment.end,
children: <Widget>[
TextField(
decoration: InputDecoration(labelText: 'Title'),
controller: _titleController,
onSubmitted: (_) => _submitData(),
// onChanged: (val) {
// titleInput = val;
// },
),
TextField(
decoration: InputDecoration(labelText: 'Amount'),
controller: _amountController,
keyboardType: TextInputType.number,
onSubmitted: (_) => _submitData(),
// onChanged: (val) => amountInput = val,
),
Container(
height: 70,
child: Row(
children: <Widget>[
Expanded(
child: Text(
_selectedDate == null
? 'No Date Chosen!'
: 'Picked Date: ${DateFormat.yMd().format(_selectedDate)}',
),
),
// ignore: deprecated_member_use
FlatButton(
textColor: Theme.of(context).primaryColor,
child: Text(
'Choose Date',
style: TextStyle(
fontWeight: FontWeight.bold,
),
),
onPressed: _presentDatePicker,
),
],
),
),
// ignore: deprecated_member_use
RaisedButton(
child: Text('Add Transaction'),
color: Theme.of(context).primaryColor,
textColor: Theme.of(context).primaryColor,
onPressed: _submitData,
),
],
),
),
);
}
}
Here in the above code. _selectedDate is giving me error. I just looked after adding late but its not also error and here is the error message,
Non-nullable instance field '_selectedDate' must be initialized.
Try adding an initializer expression, or a generative constructor that initializes it, or mark it 'late'.
You can make it nullable like this:
DateTime? _selectedDate;
This question already has answers here:
Null check operator used on a null value
(12 answers)
Closed last year.
I am new to programming and don't know how to solve this issue.
I am using the java version of 8 and using Android Studio to make apps with Flutter.
I have been making a to-do list app, and a cast error happens when
I make a new list
I update a list
I delete a list
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter ToDo List',
debugShowCheckedModeBanner: false,
theme: ThemeData(
fontFamily: "NanumSquare",
primaryColor: Color(0xFF424874), //primary color
),
home: HomeScreen()
);
}
}
this is the main.dart
the error appears on the Home Screen.
class HomeScreen extends StatefulWidget {
#override
_HomeScreenState createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
late Future<List<Note>> _noteList;
final DateFormat _dateFormatter = DateFormat("MMM dd, yyyy");
DatabaseHelper _databaseHelper = DatabaseHelper.instance;
void initState() {
super.initState();
_updateNoteList();
}
_updateNoteList() {
_noteList = DatabaseHelper.instance.getNoteList();
}
Widget _buildNote(Note note) {
return Padding(
padding: EdgeInsets.symmetric(horizontal: 25),
child: Column(
children: [
Container(
margin: EdgeInsets.all(5),
color: Color(0xFFDCD6F7),
child: ListTile(
title: Text(
note.title!,
style: TextStyle(
fontSize: 20,
color: Color(0xFF424874),
decoration: note.status == 0
? TextDecoration.none
: TextDecoration.lineThrough),
),
subtitle: Text(
"${_dateFormatter.format(note.date!)}-${note.priority}",
style: TextStyle(
fontSize: 15,
color: Color(0xFF424874),
decoration: note.status == 0
? TextDecoration.none
: TextDecoration.lineThrough),
),
trailing: Checkbox(
onChanged: (value) {
note.status = value! ? 1 : 0;
DatabaseHelper.instance.updateNote(note);
_updateNoteList();
Navigator.pushReplacement(
context, MaterialPageRoute(builder: (_) => HomeScreen())
);
},
activeColor: Color(0xFFA6B1E1),
value: note.status == 1 ? true : false,
),
onTap: () => Navigator.push(
context,
CupertinoPageRoute(
builder: (_) => AddNoteScreen(
updateNoteList: _updateNoteList(),
note: note
)
),
),
),
),
Divider(
height: 5,
color: Color(0xFFA6B1E1),
thickness: 2,
)
],
),
);
}
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Color(0xFFF4EEFF),
floatingActionButton: FloatingActionButton(
backgroundColor: Color(0xFF424874),
onPressed: () {
Navigator.push(
context,
CupertinoPageRoute(
builder: (_) => AddNoteScreen(
updateNoteList: _updateNoteList(),
),
));
},
child: Icon(Icons.add),
),
body: FutureBuilder(
future: _noteList,
builder: (context, AsyncSnapshot snapshot) {
if (!snapshot.hasData) {
return Center(
child: CircularProgressIndicator(),
);
}
final int completedNoteCount = snapshot.data!.where((Note note) => note.status == 1).toList().length;
return ListView.builder(
padding: EdgeInsets.symmetric(vertical: 80),
itemCount: int.parse(snapshot.data!.length.toString()) + 1,
itemBuilder: (BuildContext context, int index) {
if (index == 0) {
return Padding(
padding:
EdgeInsets.symmetric(horizontal: 40, vertical: 20),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
"My Notes",
style: TextStyle(
color: Color(0xFF424874),
fontSize: 40,
fontWeight: FontWeight.bold),
),
SizedBox(
height: 10,
),
Text(
"$completedNoteCount of ${snapshot.data.length}",
style: TextStyle(
color: Color(0xFFA6B1E1),
fontSize: 20,
fontWeight: FontWeight.w600),
),
],
),
);
}
return _buildNote(snapshot.data![index-1]);
});
}));
}
}
The error message is as below.
======== Exception caught by gesture ===============================================================
The following _CastError was thrown while handling a gesture:
Null check operator used on a null value
When the exception was thrown, this was the stack:
#0 _AddNoteScreenState._delete (package:crud_sqlite_app/screens/add_note_screen.dart:80:26)
#1 _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:989:21)
#2 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:182:24)
#3 TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:607:11)
#4 BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:296:5)
...
Handler: "onTap"
Recognizer: TapGestureRecognizer#e7613
debugOwner: GestureDetector
state: ready
won arena
finalPosition: Offset(150.8, 655.2)
finalLocalPosition: Offset(110.8, 46.2)
button: 1
sent tap down
====================================================================================================
and this is the add_note_screen.dart
class AddNoteScreen extends StatefulWidget {
final Note? note;
final Function? updateNoteList;
AddNoteScreen({this.note, this.updateNoteList});
#override
_AddNoteScreenState createState() => _AddNoteScreenState();
}
class _AddNoteScreenState extends State<AddNoteScreen> {
final _formKey = GlobalKey<FormState>();
String _title = "";
String _priority = "Low";
String btnText = "Add Note";
String titleText = "Add Note";
DateTime _date = DateTime.now();
TextEditingController _dateController = TextEditingController();
final DateFormat _dateFormatter = DateFormat("MMM dd, yyyy");
final List<String> _priorities = ["Low", "Medium", "High"];
#override
void initState(){
super.initState();
if(widget.note != null) {
_title = widget.note!.title!;
_date = widget.note!.date!;
_priority = widget.note!.priority!;
setState(() {
btnText = "Update Note";
titleText = "Update Note";
});
}
else {
setState(() {
btnText = "Add Note";
titleText = "Add Note";
});
}
_dateController.text = _dateFormatter.format(_date);
}
#override
void dispose() {
_dateController.dispose();
super.dispose();
}
_handleDatePicker() async {
final DateTime? date = await showDatePicker(
context: context,
initialDate: _date,
firstDate: DateTime(2000),
lastDate: DateTime(2100));
if (date != null && date != _date) {
setState(() {
_date = date;
});
_dateController.text = _dateFormatter.format(date);
}
}
_delete() {
DatabaseHelper.instance.deleteNote(widget.note!.id!);
Navigator.pushReplacement(
context,
MaterialPageRoute(
builder: (_)=> HomeScreen()
)
);
widget.updateNoteList!();
}
_submit() {
if (_formKey.currentState!.validate()) {
_formKey.currentState!.save();
print("$_title, $_date, $_priority");
Note note = Note(
title: _title,
date: _date,
priority: _priority
);
if (widget.note == null){
note.status = 0;
DatabaseHelper.instance.insertNote(note);
Navigator.pushReplacement(context, MaterialPageRoute(builder: (_)=> HomeScreen())
);
}
else{
note.id = widget.note!.id;
note.status = widget.note!.status;
DatabaseHelper.instance.updateNote(note);
Navigator.pushReplacement(context, MaterialPageRoute(builder: (_)=> HomeScreen())
);
}
widget.updateNoteList!();
}
}
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Color(0xFFF4EEFF),
body: GestureDetector(
onTap: () => FocusScope.of(context).unfocus(),
child: SingleChildScrollView(
child: Container(
padding: EdgeInsets.symmetric(horizontal: 40, vertical: 80),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
GestureDetector(
onTap: () => Navigator.pushReplacement(
context,
MaterialPageRoute(
builder: (_) => HomeScreen(),
)
),
child: Icon(
Icons.arrow_back,
size: 30,
color: Color(0xFFA6B1E1),
),
),
SizedBox(
height: 20.0,
),
Text(
titleText,
style: TextStyle(
color: Color(0xFF424874),
fontSize: 40,
fontWeight: FontWeight.bold),
),
SizedBox(
height: 10,
),
Form(
key: _formKey,
child: Column(
children: <Widget>[
Padding(
padding: EdgeInsets.symmetric(vertical: 20),
child: TextFormField(
style: TextStyle(fontSize: 18),
decoration: InputDecoration(
labelText: "Title",
labelStyle: TextStyle(fontSize: 18),
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(10))),
validator: (input) => input!.trim().isEmpty
? "Please enter a note title"
: null,
onSaved: (input) => _title = input!,
initialValue: _title,
),
),
Padding(
padding: EdgeInsets.symmetric(vertical: 20),
child: TextFormField(
readOnly: true, //hide keyboard
controller: _dateController,
style: TextStyle(fontSize: 18),
onTap: _handleDatePicker,
decoration: InputDecoration(
labelText: "Date",
labelStyle: TextStyle(fontSize: 18),
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(10))),
),
),
Padding(
padding: EdgeInsets.symmetric(vertical: 20),
child: DropdownButtonFormField(
isDense: true,
icon: Icon(Icons.arrow_drop_down_circle),
iconSize: 22,
iconEnabledColor: Color(0xFF424874),
items: _priorities.map((String priority) {
return DropdownMenuItem(
value: priority,
child: Text(
priority,
style: TextStyle(
color: Colors.black,
fontSize: 18,
),
));
}).toList(),
style: TextStyle(fontSize: 18),
decoration: InputDecoration(
labelText: "Priority",
labelStyle: TextStyle(fontSize: 18),
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(10)
)
),
// validator: (input) => _priority == null ? "Please",
onChanged: (value) {
setState(() {
_priority = value.toString();
});
},
value: _priority,
),
),
Container(
margin: EdgeInsets.symmetric(vertical: 20),
height: 60.0,
width: double.infinity,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(30)),
child: ElevatedButton(
style: ButtonStyle(
backgroundColor: MaterialStateProperty.all(Theme.of(context).primaryColor)
),
child: Text(
btnText,
style: TextStyle(color: Colors.white, fontSize: 20),
),
onPressed: _submit,
),
),
widget.note != null ? Container(
margin: EdgeInsets.symmetric(vertical: 20),
height: 60,
width: double.infinity,
decoration: BoxDecoration(
color: Color(0xFF424874),
borderRadius: BorderRadius.circular(30)
),
child: ElevatedButton(
style: ButtonStyle(
backgroundColor: MaterialStateProperty.all(Theme.of(context).primaryColor)
),
child: Text("Delete Note",
style: TextStyle(
color: Colors.white,
fontSize: 20
),
),
onPressed: _delete,
),
): SizedBox.shrink()
],
),
)
],
),
),
),
),
);
}
}
I am sorry the code is too long.
If you can help me, I will really appreciate it.
Thank you!
This error occurs when you use a bang operator (!) on a nullable instance which wasn't initialized. This operator should only be used when you are sure that the variable cannot be null, I don't recommend using it. Check out this answer
I'm trying to update the card data I brought from firestore
when I use onTap in Inkwell I want to change data in this card.
this is my search service. I am using this for bring data from firestore
how can I make update function on this situation. thanks for help
class SearchService {
List<Future<QuerySnapshot>> searchByName() {
return [
Firestore.instance
.collection('dis')
.where('no')
.orderBy('date', descending: true )
.getDocuments(),
];
}
}
this is my Card code
Widget buildResultCard(BuildContext context , data) {
return Card(
shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(5.0)),
elevation: 5,
child: ExpansionCard(
title: Column(
children: [
Row(
children: [
Padding(
padding: EdgeInsets.fromLTRB(5, 0, 5, 1),
child: Text(data['isim'],
style: GoogleFonts.montserrat(color: Colors.blueGrey[700], fontSize: 20 , textStyle: TextStyle(fontWeight: FontWeight.w400)),
textAlign: TextAlign.center,
),
),
InkWell(
child: Icon(
Icons.update,
color: Colors.white54,
),
onTap: (){//I want to set update function here//
},
)
],
),
);
}
and this is my adddata function
Future<void> addData(carData) async {
if (isLoggedIn()) {
Firestore.instance.collection('dis').add(carData).catchError((e) {
print(e);
});
} else {
print('You need to be logged in');
}
}
a little bit long but this is my addmethod
crudMedthods crudObj = new crudMedthods();
Future<bool> addDialog(BuildContext context) async {
return showDialog(
context: context,
barrierDismissible: false,
builder: (BuildContext context) {
final _width = MediaQuery.of(context).size.width;
return AlertDialog(
title: Text('Temsilci Verisi Ekleyin.', style: GoogleFonts.montserrat(color: Colors.black54,
fontSize: 22 , textStyle: TextStyle(fontWeight: FontWeight.w300)),
textAlign: TextAlign.center,),
content: SingleChildScrollView(
child: Container(
width: _width,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Column(
children: [
TextField(
onTap: (){
showDatePicker(context: context,
initialDate: _dateTime == null ? DateTime.now() : _dateTime,
firstDate: DateTime(2000),
lastDate: DateTime(2030)).then((date) {
setState(() {
_dateTime = date;
});
});
},
decoration: InputDecoration(hintText: _dateTime == null ? 'Uygulama Sıralama
Takvimi Giriniz' : _dateTime.toString()),
onChanged: (value) {
this._dateTime = value as DateTime;
},
),
],
),
SizedBox(height: 5.0),
TextField(
decoration: InputDecoration(hintText: 'Temsilci'),
onChanged: (value) {
this.temsilci = value;
},
),
SizedBox(height: 5.0),
TextField(
decoration: InputDecoration(hintText: 'Sıra No'),
onChanged: (value) {
this.sirano = value;
},
),
SizedBox(height: 5.0),
TextField(
decoration: InputDecoration(hintText: 'Tarih'),
onChanged: (value) {
this.tarih = value;
},
),
SizedBox(height: 5.0),
TextField(
decoration: InputDecoration(hintText: 'Veri Kaynağı'),
onChanged: (value) {
this.verik = value;
},
),
],
),
),
),
actions: <Widget>[
FlatButton(
child: Text('Verileri Sisteme Ekleyin'),
textColor: Colors.blue,
onPressed: () {
Navigator.of(context).pop();
crudObj.addData({
'date': this._dateTime,
'no': this.no,
'temsilci': this.temsilci,
'sıra no': this.sirano,
'tarih': this.tarih,
'veri kaynağı': this.verik,
}).then((result) {
dialogTrigger(context);
}).catchError((e) {
print(e);
});
},
)
],
);
});
}
import 'dart:async';
import 'dart:io';
import 'dart:typed_data';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:image_gallery_saver/image_gallery_saver.dart';
import 'package:image_picker/image_picker.dart';
import 'package:qrscan/qrscan.dart' as scanner;
void main() {
runApp(MyApp());
}
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
Uint8List bytes = Uint8List(0);
TextEditingController _inputController;
TextEditingController _outputController;
#override
initState() {
super.initState();
this._inputController = new TextEditingController();
this._outputController = new TextEditingController();
}
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: Scaffold(
backgroundColor: Colors.grey[300],
body: Builder(
builder: (BuildContext context) {
return ListView(
children: <Widget>[
_qrCodeWidget(this.bytes, context),
Container(
color: Colors.white,
child: Column(
children: <Widget>[
TextField(
controller: this._inputController,
keyboardType: TextInputType.url,
textInputAction: TextInputAction.go,
onSubmitted: (value) => _generateBarCode(value),
decoration: InputDecoration(
prefixIcon: Icon(Icons.text_fields),
helperText: 'Please input your code to generage qrcode image.',
hintText: 'Please Input Your Code',
hintStyle: TextStyle(fontSize: 15),
contentPadding: EdgeInsets.symmetric(
horizontal: 7, vertical: 15),
),
),
SizedBox(height: 20),
TextField(
controller: this._outputController,
maxLines: 2,
decoration: InputDecoration(
prefixIcon: Icon(Icons.wrap_text),
helperText: 'The barcode or qrcode you scan will be displayed in this area.',
hintText: 'The barcode or qrcode you scan will be displayed in this area.',
hintStyle: TextStyle(fontSize: 15),
contentPadding: EdgeInsets.symmetric(
horizontal: 7, vertical: 15),
),
),
SizedBox(height: 20),
this._buttonGroup(),
SizedBox(height: 70),
],
),
),
],
);
},
),
floatingActionButton: FloatingActionButton(
onPressed: () => _scanBytes(),
tooltip: 'Take a Photo',
child: const Icon(Icons.camera_alt),
),
),
);
}
Widget _qrCodeWidget(Uint8List bytes, BuildContext context) {
return Padding(
padding: EdgeInsets.all(20),
child: Card(
elevation: 6,
child: Column(
children: <Widget>[
Container(
child: Row(
crossAxisAlignment: CrossAxisAlignment.end,
children: <Widget>[
Icon(Icons.verified_user, size: 18, color: Colors.green),
Text(' Generate Qrcode', style: TextStyle(fontSize: 15)),
Spacer(),
Icon(Icons.more_vert, size: 18, color: Colors.black54),
],
),
padding: EdgeInsets.symmetric(horizontal: 10, vertical: 9),
decoration: BoxDecoration(
color: Colors.black12,
borderRadius: BorderRadius.only(
topLeft: Radius.circular(4), topRight: Radius.circular(4)),
),
),
Padding(
padding: EdgeInsets.only(
left: 40, right: 40, top: 30, bottom: 10),
child: Column(
children: <Widget>[
SizedBox(
height: 190,
child: bytes.isEmpty
? Center(
child: Text('Empty code ... ',
style: TextStyle(color: Colors.black38)),
)
: Image.memory(bytes),
),
Padding(
padding: EdgeInsets.only(top: 7, left: 25, right: 25),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
Expanded(
flex: 5,
child: GestureDetector(
child: Text(
'remove',
style: TextStyle(
fontSize: 15, color: Colors.blue),
textAlign: TextAlign.left,
),
onTap: () =>
this.setState(() => this.bytes = Uint8List(0)),
),
),
Text('|', style: TextStyle(fontSize: 15, color: Colors
.black26)),
Expanded(
flex: 5,
child: GestureDetector(
onTap: () async {
final success = await ImageGallerySaver.saveImage(
this.bytes);
SnackBar snackBar;
if (success) {
snackBar = new SnackBar(content: new Text(
'Successful Preservation!'));
Scaffold.of(context).showSnackBar(snackBar);
} else {
snackBar =
new SnackBar(content: new Text('Save failed!'));
}
},
child: Text(
'save',
style: TextStyle(
fontSize: 15, color: Colors.blue),
textAlign: TextAlign.right,
),
),
),
],
),
)
],
),
),
Divider(height: 2, color: Colors.black26),
],
),
),
);
}
Widget _buttonGroup() {
return Row(
children: <Widget>[
Expanded(
flex: 1,
child: SizedBox(
height: 120,
child: InkWell(
onTap: () => _generateBarCode(this._inputController.text),
child: Card(
child: Column(
children: <Widget>[
Expanded(
flex: 2,
child: Image.asset('images/generate_qrcode.png'),
),
Divider(height: 20),
Expanded(flex: 1, child: Text("Generate")),
],
),
),
),
),
),
Expanded(
flex: 1,
child: SizedBox(
height: 120,
child: InkWell(
onTap: _scan,
child: Card(
child: Column(
children: <Widget>[
Expanded(
flex: 2,
child: Image.asset('images/scanner.png'),
),
Divider(height: 20),
Expanded(flex: 1, child: Text("Scan")),
],
),
),
),
),
),
Expanded(
flex: 1,
child: SizedBox(
height: 120,
child: InkWell(
onTap: _scanPhoto,
child: Card(
child: Column(
children: <Widget>[
Expanded(
flex: 2,
child: Image.asset('images/albums.png'),
),
Divider(height: 20),
Expanded(flex: 1, child: Text("Scan Photo")),
],
),
),
),
),
),
],
);
}
Future _scan() async {
String barcode = await scanner.scan();
if (barcode == null) {
print('nothing return.');
} else {
this._outputController.text = barcode;
}
}
Future _scanPhoto() async {
String barcode = await scanner.scanPhoto();
this._outputController.text = barcode;
}
Future _scanPath(String path) async {
String barcode = await scanner.scanPath(path);
this._outputController.text = barcode;
}
Future _scanBytes() async {
File file = await ImagePicker.pickImage(source: ImageSource.camera);
Uint8List bytes = file.readAsBytesSync();
String barcode = await scanner.scanBytes(bytes);
this._outputController.text = barcode;
}
Future _generateBarCode(String inputCode) async {
Uint8List result = await scanner.generateBarCode(inputCode);
this.setState(() => this.bytes = result);
}
}
class MyAppState extends State<MyApp> {
Future<SharedPreferences> _sPrefs = SharedPreferences.getInstance();
final TextEditingController controller = TextEditingController();
List<String> listOne, listTwo;
#override
void initState() {
super.initState();
listOne = [];
listTwo = [];
}
Future<Null> addString() async {
final SharedPreferences prefs = await _sPrefs;
listOne.add(controller.text);
prefs.setStringList('list', listOne);
setState(() {
controller.text = '';
});
}
Future<Null> clearItems() async {
final SharedPreferences prefs = await _sPrefs;
prefs.clear();
setState(() {
listOne = [];
listTwo = [];
});
}
Future<Null> getStrings() async {
final SharedPreferences prefs = await _sPrefs;
listTwo = prefs.getStringList('list');
setState(() {});
}
Future<Null> updateStrings(String str) async {
final SharedPreferences prefs = await _sPrefs;
setState(() {
listOne.remove(str);
listTwo.remove(str);
});
prefs.setStringList('list', listOne);
}
#override
Widget build(BuildContext context) {
getStrings();
return Center(
child: ListView(
children: <Widget>[
TextField(
controller: controller,
decoration: InputDecoration(
hintText: 'Type in something...',
)),
RaisedButton(
child: Text("Submit"),
onPressed: () {
addString();
},
),
RaisedButton(
child: Text("Clear"),
onPressed: () {
clearItems();
},
),
Flex(
direction: Axis.vertical,
children: listTwo == null
? []
: listTwo
.map((String s) => Dismissible(
key: Key(s),
onDismissed: (direction) {
updateStrings(s);
},
child: ListTile(
title: Text(s),
)))
.toList(),
)
],
),
);
}
}
Here the first Appstate creates a Qr code reader. Second is for creating an input controller with shared preferences that can store and retrieve data locally. But when running the code the app displays only the qrscan part and 2nd is not working. I'm new to Flutter. I've just started working on Android Studio. Can anybody help please?
Try to call Another class from home property of the MyApp class.
As you can see in this image
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue),
debugShowCheckedModeBanner: false,
//Here I have called MyWidget Class
home: MyWidget()
);
}
}
class MyWidget extends StatefulWidget {
#override
_MyWidgetState createState() => _MyWidgetState();
}
class _MyWidgetState extends State<MyWidget> {
Uint8List bytes = Uint8List(0);
TextEditingController _inputController;
TextEditingController _outputController;
#override
initState() {
super.initState();
this._inputController = new TextEditingController();
this._outputController = new TextEditingController();
}
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: Scaffold(