Flutter rest GETX map inside Obx not refreshing data on gui side - flutter

Hello I have simple script I download data from from Rest api , there is my controller
and when I submit the button I Clear the list inside object Employee, after click I call the deleteEmployee() (int the future CRUD operations per row inside table,) , data are cleared, but data inside widget they are not refreshed. and I would like somethin more with that I need to show in table and make same operation per row.
I cant figure where is a problem.
after click the button must look like
class EmployeeController extends GetxController {
var empData = <Employe>[].obs;
#override
void onInit() {
fetchEmployee();
super.onInit();
}
void fetchEmployee() async {
final response =
await http.get(
Uri.parse('http://dummy.restapiexample.com/api/v1/employees'));
if (response.statusCode == 200) {
final string = response.body;
final parsed = json.decode(string);
Employe emp = Employe.fromJson(parsed);
Employe empx = Employe( message: "sampleTest", status: '123', data: emp.data.getRange(0, 4).toList() );
List<Employe> e = [];
e.add(empx);
e.add(emp);
empData.value = e;
} else {
throw Exception('Failed to load emplo');
}
}
void deleteEmployee (String enumId){
debugPrint(empData.toString());
debugPrint("before");
int index = empData.indexWhere((ele) => ele.message == enumId);
empData[index].data.clear();
debugPrint("after");
debugPrint(empData.toString());
}
}
void main() {
runApp(const MyApp());
}
final EmployeeController employeeController = Get.put(EmployeeController());
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Obx(() => Row(
children: employeeController.empData
.map(
(e) => Expanded(
child: Column(
children: [
Text(e.message),
Text(e.toString()),
IconButton(
onPressed: () {
employeeController.deleteEmployee(e.message);
},
icon: Icon(Icons.abc_rounded),
)
],
),
),
)
.toList())),
);
}
}

In _MyHomePageState try to use employeeController.empData.value instead of employeeController.empData.
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Obx(() => Row(
children: employeeController.empData.value
.map(
(e) => Expanded(
child: Column(
children: [
Text(e.message),
Text(e.toString()),
IconButton(
onPressed: () {
employeeController.deleteEmployee(e.message);
},
icon: Icon(Icons.abc_rounded),
)
],
),
),
)
.toList())),
);
}
}

Related

Show list items in a stateful widget linked to the item

I have a list of integers. Each of this item is displayed in a statefull widget by iterating the list in the build method.
import 'package:flutter/material.dart';
import 'package:widget_list/ItemWidget.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Item list state demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Item list state demo'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
static int itemsCount = 0;
final List<int> _items = List.empty(growable: true);
void _add() {
setState(() {
_items.add(itemsCount++);
});
}
void _remove() {
setState(() {
_items.removeAt(0);
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Row(
children: [
TextButton(
onPressed: () => _add(),
child: const Text('Add item'),
),
TextButton(
onPressed: () => _items.isNotEmpty ? _remove() : null,
child: const Text('Remove item'),
),
],
),
for (var item in _items) ItemWidget(item: item),
],
),
),
);
}
}
Each of this widget, has a statically incremented integer "id" in it's state. Both the item and the widget id are displayed.
import 'package:flutter/material.dart';
var widgetCount = 0;
class ItemWidget extends StatefulWidget {
final int item;
const ItemWidget({
required this.item,
Key? key,
}) : super(key: key);
#override
State<ItemWidget> createState() => _ItemWidgetState();
}
class _ItemWidgetState extends State<ItemWidget> {
final int widgetId = widgetCount++;
#override
Widget build(BuildContext context) {
print("Item ${widget.item} / Widget $widgetId");
return Text("Item ${widget.item} / Widget $widgetId");
}
}
When I add an item in the list, it is displayed in a newly generated widget. E.g. first item 0 is displayed in widget 0.
But if I remove an item at the beginning of the list (e.g. item 0), it's not the first widget that is destoyed, but the last one. The item 1 is then displayed in widget 0.
The widget item is final, so it cannot change. The widget ids are still the same, so the states were not rebuild. Then, why are the states no more consistent with the widgets?
This is done in FLutter desktop for Linux, v3.0.1
In the itemWidget you are creating a value from 0 so for each element that is rendered it will start from 0. please check the code below
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Item list state demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Item list state demo'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
static int itemsCount = 0;
final List<ItemInfo> _items = List.empty(growable: true);
void _add() {
setState(() {
itemsCount++;
_items.add(ItemInfo(itemsCount, itemsCount));
});
}
void _remove() {
setState(() {
_items.removeAt(0);
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Row(
children: [
TextButton(
onPressed: () => _add(),
child: const Text('Add item'),
),
TextButton(
onPressed: () => _items.isNotEmpty ? _remove() : null,
child: const Text('Remove item'),
),
],
),
for (var item in _items) ItemWidget(item: item),
],
),
),
);
}
}
and Itemwidget to be like this
class ItemWidget extends StatefulWidget {
final ItemInfo item;
const ItemWidget({
required this.item,
Key? key,
}) : super(key: key);
#override
State<ItemWidget> createState() => _ItemWidgetState();
}
class _ItemWidgetState extends State<ItemWidget> {
#override
Widget build(BuildContext context) {
return Text(
"Item ${widget.item.itemVal} / Widget ${widget.item.itemIndex}");
}
}
also I created a class named ItemInfo which will hold both the value and its index.
class ItemInfo {
int itemVal;
int itemIndex;
ItemInfo(this.itemVal, this.itemIndex);
}

How to fix hive box already open error in flutter?

I am trying to use hive to store data on a local machine using hive but each time when I compile the code it gives the error "The box "notebook" is already open and of type Box."
Can someone help me to resolve the issue as I am new to it? Thanks
I am just trying to add data to the database in this app without any change to the state of the app interface. I have tried to change the main method to void but no luck on this.
All the code is located in the main file
import 'package:flutter/material.dart';
import 'package:hive/hive.dart';
import 'package:hive_flutter/hive_flutter.dart';
import 'notes.dart';
import 'notesStoring.dart';
Future main() async{
WidgetsFlutterBinding.ensureInitialized();
await Hive.initFlutter();
Hive.registerAdapter(NotesAdapter());
await Hive.openBox<NotesAdapter>('noteBook');
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
#override
void dispose() {
Hive.close();
// TODO: implement dispose
super.dispose();
}
#override
Future incrementCounter(String title) async {
final notes = Notes()
..title = title;
final box =Boxes.getNotesValues();
box.add(notes);
}
final titleForNotes=TextEditingController();
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body:
Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text(
'You have pushed the button this many times:',
),
TextField(
controller: titleForNotes,
cursorColor: Colors.pink,
),
ValueListenableBuilder<Box<Notes>>(valueListenable: Boxes.getNotesValues().listenable(), builder: (context,box,_){
final noteBook =box.values.toList().cast<Notes>();
return buildContent(noteBook);
})
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: (){
incrementCounter(titleForNotes.text);
},
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
class Boxes {
static Box<Notes> getNotesValues()=>Hive.box<Notes>('noteBook');
}
Widget buildContent(List<Notes> noteBook){
return Column(
children: [
Expanded(child:
ListView.builder(
padding: EdgeInsets.all(8),
itemCount: noteBook.length,
itemBuilder: (BuildContext context, int index){
final notes= noteBook[index];
return buildTransaction(context, notes);
}
)
)
],
);
}
Widget buildTransaction(
BuildContext context,
Notes notes,
){
return Card(
color: Colors.green,
child: Text(notes.title),
);
}
1.You can open your notebook Box in the main method of your app:
Future<void> main() async {
...
final appDocumentDirectory = await
path_provider.getApplicationDocumentsDirectory();
Hive.init(appDocumentDirectory.path);
Hive.registerAdapter(UserAdapter());
// open the user box
await Hive.openBox('notebook');
_setUpLogging();
runApp(MultiProvider(providers: providers, child:
StartupApplication()));
}
2 Access the previously opened box like below:
class MyHomePage extends StatefulWidget {
const MyHomePage({Key key}) : super(key: key);
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
// user box
Box notebookBox;
#override
void initState() {
super.initState();
// get the previously opened user box
notebookBox = Hive.box('notebook');
}
#override
Widget build(BuildContext context) {
// check for your conditions
return (notebookBox.values.isNotEmpty && notebookBox.get(0).active == 1)
? HomeView()
: Intro();
}
}

Fetching data from Supabase in flutter

Anyone can help me with this, I'm trying to fetch data from a table in Supabase but it's showing error on the app screen.
I want to build an app that reads the data from Supabase without any authentication, only reading and displaying the data from the table, here I'm just testing before I start building my app.
a screenshot from the main page in the app
My code in main.dart
import 'package:flutter/material.dart';
import 'package:supabase_flutter/supabase_flutter.dart';
Future<void> main() async {
WidgetsFlutterBinding.ensureInitialized();
await Supabase.initialize(
url: '[https://bougcsiwnimbmnmvwjlb.supabase.co]',
anonKey: '[eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyb2xlIjoiYW5vbiIsImlhdCI6MTY0Mzc5NzQyOCwiZXhwIjoxOTU5MzczNDI4fQ.Ac5s-ZOyUV-2rRoP_GUuPvdt7tGNocCSq-LU-ZtBVqQ]',
);
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.red,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
// SuPabase
class _MyHomePageState extends State<MyHomePage> {
Future<void> _getProfile(String name) async {
late final _usernameController ;
#override
Future<Widget> build(BuildContext context) async {
final response = await Supabase.instance.client
.from('channels')
.select()
.single()
.execute();
if (response.error != null && response.status != null) {
ScaffoldMessenger.of(context)
.showSnackBar(SnackBar(content: Text(response.error!.message)));
}
if (response.data != null) {
_usernameController = response.data!['name'] as String;
}
return Scaffold(
appBar: AppBar(title: const Text('Profile')),
body: ListView(
padding: const EdgeInsets.symmetric(vertical: 18, horizontal: 12),
children: [
Text(_usernameController,
),
],
),
);
}
}
#override
Widget build(BuildContext context) {
throw UnimplementedError();
}
}
I really appetite if anyone can help in this.
I think I can spot few spots that you might want to fix.
First, you want to remove the [] around your Supabase URL and Supabase anon key like this.
await Supabase.initialize(
url: 'https://bougcsiwnimbmnmvwjlb.supabase.co',
anonKey: 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyb2xlIjoiYW5vbiIsImlhdCI6MTY0Mzc5NzQyOCwiZXhwIjoxOTU5MzczNDI4fQ.Ac5s-ZOyUV-2rRoP_GUuPvdt7tGNocCSq-LU-ZtBVqQ',
);
Also, it seemed like you had some mismatch of brackets in your widget definition. I think this is along the line of what you wanted to do:
class _MyHomePageState extends State<MyHomePage> {
String? name;
Future<void> _getProfile() async {
final response = await Supabase.instance.client
.from('channels')
.select()
.single()
.execute();
if (response.error != null && response.status != null) {
ScaffoldMessenger.of(context)
.showSnackBar(SnackBar(content: Text(response.error!.message)));
}
if (response.data != null) {
setState(() {
name = response.data!['name'] as String;
});
}
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: const Text('Profile')),
body: ListView(
padding: const EdgeInsets.symmetric(vertical: 18, horizontal: 12),
children: [
name == null ? const Text('loading') : Text(name!),
],
),
);
}
#override
void initState() {
_getProfile();
super.initState();
}
}

Flutter use one Variable in different classes Error: Getter not found: 'allJobs'

I have a Variable in one Class but and i want to use it in all.
In this Example is the allJobs Variable which is declared in Muesnterboerse ore MuensterboerseAAAngebote and i want to use it in senddate().
class Muensterboerse extends StatelessWidget {
var allJobs = 1;
#override
Widget build(BuildContext context) {
return new MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter App with MYSQL',
home: new MyHomePage(),
);
}
}
class MuensterboerseAAAngebote extends StatelessWidget {
var allJobs = 0;
#override
Widget build(BuildContext context) {
return new MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter App with MYSQL',
home: new MyHomePage(),
);
}
}
Future<dynamic> senddata() async {
final response = await http.post(
"https://www.bumsbirnbe.php", body: {
"status": allJobs,
});
var datauser = json.decode(response.body);
String jsonsDataString = datauser.toString();
dynamic jsonData = jsonDecode(jsonsDataString);
print(jsonData);
return jsonData;
}
Update
Now i added your changes to my code but i get the
Error: Unhandled Exception: NoSuchMethodError: The getter 'allJobs' was called on null.
This is my whole code:
import 'dart:async';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
GlobalKey _key1 = GlobalKey();
class Muensterboerse extends StatelessWidget {
Muensterboerse({Key key}) : super(key: key);
int allJobs = 1;
#override
Widget build(BuildContext context) {
return new MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter App with MYSQL',
home: new MyHomePage(),
);
}
}
class AAAngebote extends StatelessWidget {
AAAngebote({Key key}) : super(key: key);
int allJobs = 2;
#override
Widget build(BuildContext context) {
return new MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter App with MYSQL',
home: new MyHomePage(),
);
}
}
Future<dynamic> senddata() async {
int allJobs = (_key1.currentWidget as Muensterboerse).allJobs;
print(allJobs);
final response = await http.post(
"https://www.Bumsbirne.php", body: {
"status": allJobs,
});
var datauser = json.decode(response.body);
String jsonsDataString = datauser.toString();
dynamic jsonData = jsonDecode(jsonsDataString);
print(jsonData);
return jsonData;
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
dynamic jsonData;
callSendData() async {
jsonData = await senddata();
setState(() {});
}
//lol
#override
void initState() {
callSendData();
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: jsonData == null
? Center(child: CircularProgressIndicator())
: ListView.builder(
padding: const EdgeInsets.all(16.0),
itemCount: jsonData == null ? 0 : jsonData.length,
itemBuilder: (context, index) {
return ListTile(
leading: CircleAvatar(
backgroundImage: NetworkImage('https://kinsta.com/de/wpcontent/uploads/sites/5/2019/09/wordpress-loggst-url-1024x512.jpg'),
radius: 27,
),
title: Text(
jsonData[index]["titel"],
),
subtitle: Text(jsonData[index]["nam_ersteller"]),
trailing: Text(
'25 Km',
style: TextStyle(color: Colors.grey,
fontSize: 12,
decoration: TextDecoration.none,
fontFamily: 'Roboto',),
),
onTap: () {
Navigator.push(context,
new MaterialPageRoute(builder: (context) => DetailPage()));
},
);
// return _buildRow(data[index]);
}));
}
}
class DetailPage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Der Job'),
),
);
}
}
You can copy paste run full code below
Step 1: You can use GlobalKey and pass to Muensterboerse(key: _key1)
Step 2: In senddata(), do (_key1.currentWidget as Muensterboerse).allJobs;
code snippet
GlobalKey _key1 = GlobalKey();
...
class Muensterboerse extends StatelessWidget {
Muensterboerse({Key key}) : super(key: key);
...
Future<dynamic> senddata() async {
int allJobs = (_key1.currentWidget as Muensterboerse).allJobs;
print(allJobs);
...
Muensterboerse(key: _key1),
output of senddata()
I/flutter (22480): 1
full code
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
GlobalKey _key1 = GlobalKey();
class Muensterboerse extends StatelessWidget {
Muensterboerse({Key key}) : super(key: key);
int allJobs = 1;
#override
Widget build(BuildContext context) {
return Column(
children: [
Text("$allJobs"),
],
);
}
}
Future<dynamic> senddata() async {
int allJobs = (_key1.currentWidget as Muensterboerse).allJobs;
print(allJobs);
/*final response = await http.post(
"https://www.quyre.de/2/Muensterboerse.N.php", body: {
"status": allJobs
});*/
}
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() async{
await senddata();
setState(() {
_counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Muensterboerse(key: _key1),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}

Flutter: Widget State: Is this code safe?

The code below is an example to illustrate this question. The code below works, however the following line:
class WidgetCustom extends StatefulWidget {
has "WidgetCustom" underlined in green in vsCode, and when the cursor is positioned over it, it shows the message:
"This class (or a class this class inherits from) is marked as #immutable, but one or more of its instance fields are not final".
The code works fine.
Is it safe to use this code?
Is there a way to achieve this without the warning?
import 'package:flutter/material.dart';
class WidgetCustom extends StatefulWidget {
_WidgetCustomState _state;
WidgetCustom({#required int iCount}) {
_state = _WidgetCustomState(iCount);
}
#override
State<StatefulWidget> createState() {
return _state;
}
int get getIcount => _state.iCount;
}
class _WidgetCustomState extends State<WidgetCustom> {
int iCount;
_WidgetCustomState(this.iCount);
#override
Widget build(BuildContext context) {
return Container(
child: Row(children: <Widget>[
Column(
children: <Widget>[
RaisedButton(
child: const Text("Please tap me"),
onPressed: () {
setState(() => iCount = iCount + 1);
}),
SizedBox(height: 40),
Text("Tapped $iCount Times")
],
),
]));
}
}
Edited to add main.dart
import 'package:flutter/material.dart';
import 'widgetCustom.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Custom Widget Demo'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
WidgetCustom _widgetCustom;
String _sMessage = "Fab has not been pressed";
#override
void initState() {
super.initState();
_widgetCustom = WidgetCustom(iCount: 99);
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Column(children: [
_widgetCustom,
SizedBox(height: 40),
Text(_sMessage),
]),
floatingActionButton: FloatingActionButton(
onPressed: _fabPressed,
tooltip: 'Get Value',
child: Icon(Icons.add),
),
);
}
_fabPressed() {
setState(() => _sMessage =
"Value from last button click = ${_widgetCustom.getIcount}");
}
}
Pass the initial value to the constructor when creating the widget as a final value, and then get it from the State class.
Updated code:
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData.dark(),
home: MyHomePage(title: 'Custom Widget Demo'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
WidgetCustom _widgetCustom;
String _sMessage = "Fab has not been pressed";
int _value = 99;
#override
void initState() {
super.initState();
_widgetCustom = WidgetCustom(iCount: _value, function: _update);
}
void _update(int value) {
setState(() {
_value = value;
_widgetCustom = WidgetCustom(iCount: _value, function: _update);
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text(widget.title)),
body: Column(
children: [
_widgetCustom,
SizedBox(height: 40),
Text(_sMessage),
],
),
floatingActionButton: FloatingActionButton(
onPressed: _fabPressed,
tooltip: 'Get Value',
child: Icon(Icons.add),
),
);
}
_fabPressed() {
setState(() => _sMessage = "Value from last button click = ${_value}");
}
}
class WidgetCustom extends StatefulWidget {
final int iCount;
final Function function;
WidgetCustom({#required this.iCount, this.function});
#override
State<StatefulWidget> createState() {
return _WidgetCustomState();
}
}
class _WidgetCustomState extends State<WidgetCustom> {
int _iCount;
#override
void initState() {
super.initState();
_iCount = widget.iCount;
}
#override
Widget build(BuildContext context) {
return Container(
child: Row(
children: <Widget>[
Column(
children: <Widget>[
RaisedButton(child: const Text("Please tap me"), onPressed: (){
_iCount = _iCount + 1;
widget.function(_iCount);
}),
SizedBox(height: 40),
Text("Tapped $_iCount Times")
],
),
],
),
);
}
}