Is it possible to have double extends in a single class? in my case, i have class class AddCreditsState extends State<AddCredits> i just want to extends the HookWidget in my class AddCreditsState extends State<AddCredits>,
class AddCreditsState extends State<AddCredits>{ // how do i insert the `HookWidget` here?
return Scaffold(
backgroundColor: Color.fromRGBO(10, 15, 39, 1),
body: SingleChildScrollView(
child: Container(
width: globals.screenWidth,
height: globals.screenHeight,
margin: EdgeInsets.only(top: 25),
child: Column(
children: [headercol, body],
)),
),
);
}
In Dart, you can implements multiple interfaces, but Dart only supports single inheritance. So, you can not extends from multiple classes.
You can though use multiple Mixins with with.
But in this particular case, what you probably want is a StatefulHookWidget, a StatefulWidget that can use hooks inside its build method.
Full source code
import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
void main() {
runApp(
MaterialApp(
debugShowCheckedModeBanner: false,
title: 'StatefulHookWidget Example',
home: HomePage(),
),
);
}
class HomePage extends StatefulHookWidget {
#override
_HomePageState createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> {
String _state = 'Hello';
#override
Widget build(BuildContext context) {
final _hookedVar = useState('Hello');
return Scaffold(
appBar: AppBar(title: Text('StatefulHookWidget Example')),
body: Container(
padding: EdgeInsets.all(16.0),
alignment: Alignment.center,
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
Text('STATE: $_state'),
const SizedBox(height: 16.0),
Text('HOOK: ${_hookedVar.value}'),
const SizedBox(height: 16.0),
ElevatedButton(
onPressed: () {
setState(() => _state = 'Goodbye');
_hookedVar.value = 'Goodbye';
},
child: Text('CLICK ME'),
)
],
),
),
);
}
}
Related
In the application, the home page is ResultScreen, which displays the entered data. If they are not there, then when you click on the button, we go to the screen with the input. When I enter text into the input and click on the Display Result button, the data should be substituted into the text field on the first screen. I implemented such functionality, but I don’t understand what argument I should substitute in main.dart. Tell me please
Text Screen:
import 'package:flutter/material.dart';
import 'package:flutter_application_1/screens/result_screen.dart';
class TextScreen extends StatefulWidget {
const TextScreen({Key? key}) : super(key: key);
#override
State<TextScreen> createState() => _TextScreenState();
}
class _TextScreenState extends State<TextScreen> {
TextEditingController textController = TextEditingController();
#override
void dispose() {
textController.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('Enter data'),
),
body: Padding(
padding: const EdgeInsets.symmetric(horizontal: 16.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisAlignment: MainAxisAlignment.center,
children: [
TextField(
controller: textController,
decoration: InputDecoration(labelText: 'Message'),
),
const SizedBox(
height: 20,
),
ElevatedButton(
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) =>
ResultScreen(textController.text)));
},
child: Text('Display result'))
],
)),
);
}
}
Result Screen:
import 'package:flutter/material.dart';
import 'package:flutter_application_1/screens/text_screen.dart';
class ResultScreen extends StatefulWidget {
final String valueText;
ResultScreen(this.valueText);
#override
State<ResultScreen> createState() => _ResultScreenState();
}
class _ResultScreenState extends State<ResultScreen> {
// navigation to text_screen
void _buttonNav() {
Navigator.push(
context, MaterialPageRoute(builder: (context) => const TextScreen()));
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('Results'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
ElevatedButton(
onPressed: _buttonNav, child: const Text('Enter data')),
const SizedBox(
height: 50,
),
Text(valueText),
const SizedBox(
height: 20,
),
],
)),
);
}
}
Main.dart:
import 'package:flutter/material.dart';
import 'package:flutter_application_1/screens/result_screen.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: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: ResultScreen(),
);
}
}
Use the following code.
What is does is, when we enter the first screen i.e. ResultScreen, we pass an empty value for the first time.
Use this in main.dart
home: ResultScreen(''),
And as you are using statefull widget for ResultScreen, you need to use widget.valueText to access it like:
Text(widget.valueText),
Is it possible to have double extends in a single class? in my case, i have class class AddCreditsState extends State<AddCredits> i just want to extends the HookWidget in my class AddCreditsState extends State<AddCredits>,
class AddCreditsState extends State<AddCredits>{ // how do i insert the `HookWidget` here?
return Scaffold(
backgroundColor: Color.fromRGBO(10, 15, 39, 1),
body: SingleChildScrollView(
child: Container(
width: globals.screenWidth,
height: globals.screenHeight,
margin: EdgeInsets.only(top: 25),
child: Column(
children: [headercol, body],
)),
),
);
}
In Dart, you can implements multiple interfaces, but Dart only supports single inheritance. So, you can not extends from multiple classes.
You can though use multiple Mixins with with.
But in this particular case, what you probably want is a StatefulHookWidget, a StatefulWidget that can use hooks inside its build method.
Full source code
import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
void main() {
runApp(
MaterialApp(
debugShowCheckedModeBanner: false,
title: 'StatefulHookWidget Example',
home: HomePage(),
),
);
}
class HomePage extends StatefulHookWidget {
#override
_HomePageState createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> {
String _state = 'Hello';
#override
Widget build(BuildContext context) {
final _hookedVar = useState('Hello');
return Scaffold(
appBar: AppBar(title: Text('StatefulHookWidget Example')),
body: Container(
padding: EdgeInsets.all(16.0),
alignment: Alignment.center,
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
Text('STATE: $_state'),
const SizedBox(height: 16.0),
Text('HOOK: ${_hookedVar.value}'),
const SizedBox(height: 16.0),
ElevatedButton(
onPressed: () {
setState(() => _state = 'Goodbye');
_hookedVar.value = 'Goodbye';
},
child: Text('CLICK ME'),
)
],
),
),
);
}
}
I am trying to have a global integer that is displayed in a widget and then is updated by something (a button click or something) from another widget. All of the other ways i have tried don't work. What is the best way to do this?
Stack overflow says i have too much code so more text more text more text
import 'package:flutter/material.dart';
void main() {
runApp(
MaterialApp(
home: Scaffold(
body: Container(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
ScoreDisplay(),
PointButton(),
],
),
),
),
),
);
}
int score = 0;
class ScoreDisplay extends StatefulWidget {
#override
_ScoreDisplayState createState() => _ScoreDisplayState();
}
class _ScoreDisplayState extends State<ScoreDisplay> {
#override
Widget build(BuildContext context) {
return Center(
child: Container(
child: Text(
'Score: $score',
),
),
);
}
}
class PointButton extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Center(
child: Container(
child: RaisedButton(
//onPressed: //increment score,
),
),
);
}
}
You need to implement some kind of State Management for that.
Here are two basic ways to implement such a feature: with a StatefulWidget and with Riverpod.
1. With a StatefulWidget
I extracted your Scaffold as a StatefulWidget maintaining the score of your application.
I then use ScoreDisplay as a pure StatelessWidget receiving the score as a parameter. And your PointButton is also Stateless and call the ScorePage thanks to a simple VoidCallback function.
Full source code:
import 'package:flutter/material.dart';
void main() {
runApp(
MaterialApp(
home: ScorePage(),
),
);
}
class ScorePage extends StatefulWidget {
const ScorePage({
Key key,
}) : super(key: key);
#override
_ScorePageState createState() => _ScorePageState();
}
class _ScorePageState extends State<ScorePage> {
int score = 0;
#override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
ScoreDisplay(score: score),
PointButton(onIncrement: () => setState(() => score++)),
],
),
),
);
}
}
class ScoreDisplay extends StatelessWidget {
final int score;
const ScoreDisplay({Key key, this.score}) : super(key: key);
#override
Widget build(BuildContext context) {
return Center(
child: Container(
child: Text(
'Score: $score',
),
),
);
}
}
class PointButton extends StatelessWidget {
final VoidCallback onIncrement;
const PointButton({Key key, this.onIncrement}) : super(key: key);
#override
Widget build(BuildContext context) {
return Center(
child: Container(
child: ElevatedButton(
onPressed: () => onIncrement?.call(),
child: Text('CLICK ME'),
),
),
);
}
}
2. With Riverpod
Create a StateProvider:
final scoreProvider = StateProvider<int>((ref) => 0);
Watch the StateProvider:
final score = useProvider(scoreProvider).state;
Update the StateProvider
context.read(scoreProvider).state++
Full Source Code
import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
void main() {
runApp(
ProviderScope(
child: MaterialApp(
home: Scaffold(
body: Container(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
ScoreDisplay(),
PointButton(),
],
),
),
),
),
),
);
}
int score = 0;
class ScoreDisplay extends HookWidget {
#override
Widget build(BuildContext context) {
final score = useProvider(scoreProvider).state;
return Center(
child: Container(
child: Text(
'Score: $score',
),
),
);
}
}
class PointButton extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Center(
child: Container(
child: ElevatedButton(
onPressed: () => context.read(scoreProvider).state++,
child: Text('CLICK ME'),
),
),
);
}
}
final scoreProvider = StateProvider<int>((ref) => 0);
Check Riverpod Website for more info and more advanced use cases.
But you have many more flavors of State Management available.
The best example is to use "provider" package which can be found on www.pub.dev
It is very easy state management package that can help You solve this problem. Keep in my that provider instead of setState() uses notifyListener()
In the example below, what is the best construct to use to get the rack to update after a shuffle?
It seems to me that when a StatefulWidget is created, with its corresponding State Object (SO), any method that you can call from elsewhere is a method that's attached to the widget itself (not to the SO).
But, to get the widget to update its display, the SetState() method can only go in the SO's method(s). So how does the method on the widget call a method on its SO?
import 'package:flutter/material.dart';
List<Block> g_blocks = [Block(Colors.red), Block(Colors.green), Block(Colors.blue)];
Rack g_rack = new Rack();
void main() => runApp(MyApp());
// This widget is the root of your application.
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData(
fontFamily: 'PressStart',
),
home: MyHomeScreen(),
);
}
}
class MyHomeScreen extends StatefulWidget {
MyHomeScreen({Key key}) : super(key: key);
createState() => MyHomeScreenState();
}
class MyHomeScreenState extends State<MyHomeScreen> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Center(child: Text('Thanks for your help')),
backgroundColor: Colors.pink,
),
body: Center(
child: g_rack,
),
bottomNavigationBar: SizedBox(
height: 100.0,
child: BottomNavigationBar(
currentIndex: 0,
iconSize: 48.0,
backgroundColor: Colors.lightBlue[100],
items: [
BottomNavigationBarItem(
label: 'Shuffle',
icon: Icon(Icons.home),
),
BottomNavigationBarItem(
label: 'Shuffle',
icon: Icon(Icons.home),
),
],
onTap: (int indexOfItem) {
setState(() {
g_blocks.shuffle;
rack.updateScreen(); // ** How to get the rack to update? **
});
},
),
),
);
} // build
} // End class MyHomeScreenState
class Rack extends StatefulWidget {
#override
_rackState createState() => _rackState();
}
class _rackState extends State<Rack> {
#override
Widget build(BuildContext context) {
return Container(
height: 150.0,
color: Colors.yellow[200],
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
// mainAxisAlignment: MainAxisAlignment.spaceBetween,
mainAxisSize: MainAxisSize.max,
children: g_blocks),
);
}
void updateRack(){
setState(() {
g_blocks.shuffle;
});
}
}
class Block extends StatelessWidget {
final Color color;
Block(this.color);
#override
Widget build(BuildContext context) {
return Container(height:50,width:50, color: color,);
}
}
Here is a solution where I try to decouple the State Management and Business Logic of the application from the User Interface.
I used the following packages:
freezed for the Domain Entities
hooks_riverpod for the State Management
1. Domain Layer: Entities
We need two Entities to model our Racks of Blocks.
Blocks are defined by their color.
Blocks have no business logic.
Racks are ordered lists of Blocks.
Racks can get shuffled.
Racks can be randomly created for a (random or given) number of Blocks
#freezed
abstract class Block with _$Block {
const factory Block({Color color}) = _Block;
}
#freezed
abstract class Rack implements _$Rack {
const factory Rack({List<Block> blocks}) = _Rack;
const Rack._();
static Rack create([int nbBlocks]) => Rack(
blocks: List.generate(
nbBlocks ?? 4 + random.nextInt(6),
(index) => Block(
color: Color(0x66000000 + random.nextInt(0xffffff)),
),
),
);
Rack get shuffled => Rack(blocks: blocks..shuffle());
}
We use the freeze package to have immutability and the precious copyWith method to manage our States.
2. Application Layer: State Management
We use Hooks Riverpod for our State Management. We just need one StateNotifier and its provider.
This StateNotifierProvider gives access to both the Rack State and the core functionalities that are deal() and shuffle().
class RackStateNotifier extends StateNotifier<Rack> {
static final provider =
StateNotifierProvider<RackStateNotifier>((ref) => RackStateNotifier());
RackStateNotifier([Rack state]) : super(state ?? Rack.create());
void shuffle() {
state = state.shuffled;
}
void deal() {
state = Rack.create();
}
}
3. Presentation Layer: User Interface
The User Interface is made of four Widgets:
AppWidget [StatelessWidget]
HomePage [HookWidget]
RackWidget [StatelessWidget]
BlockWidget [StatelessWidget]
As you see, the only Widget that really cares about the State of the Application is the HomePage.
3.1 AppWidget
class AppWidget extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
theme: ThemeData(
primaryColor: Colors.amber,
accentColor: Colors.black87,
),
home: HomePage(),
);
}
}
3.2 HomePage
class HomePage extends HookWidget {
#override
Widget build(BuildContext context) {
final rack = useProvider(RackStateNotifier.provider.state);
return Scaffold(
appBar: AppBar(
title: Row(
children: const [
Icon(Icons.casino_outlined),
SizedBox(
width: 8.0,
),
Text('Rack Shuffler'),
],
),
),
body: Center(
child: RackWidget(rack: rack),
),
bottomNavigationBar: BottomAppBar(
color: Theme.of(context).primaryColor,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: [
IconButton(
icon: Icon(Icons.refresh),
iconSize: 48,
onPressed: () => context.read(RackStateNotifier.provider).deal(),
),
IconButton(
icon: Icon(Icons.shuffle),
iconSize: 48,
onPressed: () =>
context.read(RackStateNotifier.provider).shuffle(),
),
],
),
),
);
}
}
rack is provided by our StateNotifierProvider, in watch mode:
final rack = useProvider(RackStateNotifier.provider.state);
The Racks are dealt and shuffled using the same provider, in read mode:
...
context.read(RackStateNotifier.provider).deal(),
...
context.read(RackStateNotifier.provider).shuffle(),
...
3.3 RackWidget
class RackWidget extends StatelessWidget {
final Rack rack;
const RackWidget({Key key, this.rack}) : super(key: key);
#override
Widget build(BuildContext context) {
return Padding(
padding: const EdgeInsets.all(8.0),
child: LayoutBuilder(
builder: (context, constraints) {
return Row(
children: rack.blocks
.map((block) => BlockWidget(
block: block,
size: constraints.biggest.width / rack.blocks.length))
.toList(),
);
},
),
);
}
}
Basic StatelessWidget. We use a LayoutBuilder to define the size of the BlockWidgets.
3.4 BlockWidget
class BlockWidget extends StatelessWidget {
final Block block;
final double size;
const BlockWidget({
Key key,
this.block,
this.size,
}) : super(key: key);
#override
Widget build(BuildContext context) {
return SizedBox(
width: size,
height: size,
child: Padding(
padding: EdgeInsets.all(size / 10),
child: Container(
decoration: BoxDecoration(
color: block.color,
border: Border.all(color: Colors.black87, width: size / 20),
borderRadius: BorderRadius.circular(size / 15),
),
),
),
);
}
}
Another basic StatelessWidget.
Full Application Code
Just copy-paste the following to try it out.
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:freezed_annotation/freezed_annotation.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
part '66053795.shuffle.freezed.dart';
Random random = Random();
void main() => runApp(ProviderScope(child: AppWidget()));
class AppWidget extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
theme: ThemeData(
primaryColor: Colors.amber,
accentColor: Colors.black87,
),
home: HomePage(),
);
}
}
class HomePage extends HookWidget {
#override
Widget build(BuildContext context) {
final rack = useProvider(RackStateNotifier.provider.state);
return Scaffold(
appBar: AppBar(
title: Row(
children: const [
Icon(Icons.casino_outlined),
SizedBox(
width: 8.0,
),
Text('Rack Shuffler'),
],
),
),
body: Center(
child: RackWidget(rack: rack),
),
bottomNavigationBar: BottomAppBar(
color: Theme.of(context).primaryColor,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: [
IconButton(
icon: Icon(Icons.refresh),
iconSize: 48,
onPressed: () => context.read(RackStateNotifier.provider).deal(),
),
IconButton(
icon: Icon(Icons.shuffle),
iconSize: 48,
onPressed: () =>
context.read(RackStateNotifier.provider).shuffle(),
),
],
),
),
);
}
}
class RackWidget extends StatelessWidget {
final Rack rack;
const RackWidget({Key key, this.rack}) : super(key: key);
#override
Widget build(BuildContext context) {
return Padding(
padding: const EdgeInsets.all(8.0),
child: LayoutBuilder(
builder: (context, constraints) {
return Row(
children: rack.blocks
.map((block) => BlockWidget(
block: block,
size: constraints.biggest.width / rack.blocks.length))
.toList(),
);
},
),
);
}
}
class BlockWidget extends StatelessWidget {
final Block block;
final double size;
const BlockWidget({
Key key,
this.block,
this.size,
}) : super(key: key);
#override
Widget build(BuildContext context) {
return SizedBox(
width: size,
height: size,
child: Padding(
padding: EdgeInsets.all(size / 10),
child: Container(
decoration: BoxDecoration(
color: block.color,
border: Border.all(color: Colors.black87, width: size / 20),
borderRadius: BorderRadius.circular(size / 15),
),
),
),
);
}
}
class RackStateNotifier extends StateNotifier<Rack> {
static final provider =
StateNotifierProvider<RackStateNotifier>((ref) => RackStateNotifier());
RackStateNotifier([Rack state]) : super(state ?? Rack.create());
void shuffle() {
state = state.shuffled;
}
void deal() {
state = Rack.create();
}
}
#freezed
abstract class Block with _$Block {
const factory Block({Color color}) = _Block;
}
#freezed
abstract class Rack implements _$Rack {
const factory Rack({List<Block> blocks}) = _Rack;
const Rack._();
static Rack create([int nbBlocks]) => Rack(
blocks: List.generate(
nbBlocks ?? 4 + random.nextInt(6),
(index) => Block(
color: Color(0x66000000 + random.nextInt(0xffffff)),
),
),
);
Rack get shuffled => Rack(blocks: blocks..shuffle());
}
Here is a solution using a GlobalKey.
It feels pretty inelegant. It surprises me that with the close relationship between the widget and its state object, there's no easy way for a widget's method to call a method on the SO. The "widget.blah" construct provides a way for the SO to access the widget's data, is there a reason for not having a similar "state.myMethod" construct?
Anyway, the following works:
import 'package:flutter/material.dart';
List<Block> g_blocks = [Block(Colors.red), Block(Colors.green),
Block(Colors.blue), Block(Colors.purple)];
GlobalKey g_key = GlobalKey();
Rack g_rack = new Rack(key: g_key);
void main() => runApp(MyApp());
// This widget is the root of your application.
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData(
fontFamily: 'PressStart',
),
home: MyHomeScreen(),
);
}
}
class MyHomeScreen extends StatefulWidget {
MyHomeScreen({Key key}) : super(key: key);
createState() => MyHomeScreenState();
}
class MyHomeScreenState extends State<MyHomeScreen> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Center(child: Text('Thanks for your help')),
backgroundColor: Colors.pink,
),
body: Center(
child: g_rack,
),
bottomNavigationBar: SizedBox(
height: 100.0,
child: BottomNavigationBar(
currentIndex: 0,
iconSize: 48.0,
backgroundColor: Colors.lightBlue[100],
items: [
BottomNavigationBarItem(
label: 'Shuffle',
icon: Icon(Icons.home),
),
BottomNavigationBarItem(
label: 'Shuffle',
icon: Icon(Icons.home),
),
],
onTap: (int index) {
g_blocks.shuffle();
g_key.currentState.setState(() {
});
}
),
),
);
} // build
} // End class MyHomeScreenState
class Rack extends StatefulWidget {
Rack({Key key}) : super(key: key);
#override
_rackState createState() => _rackState();
}
class _rackState extends State<Rack> {
#override
Widget build(BuildContext context) {
return Container(
height: 150.0,
color: Colors.yellow[200],
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
mainAxisSize: MainAxisSize.max,
children: g_blocks),
);
}
void updateRack(){
setState(() {});
}
}
class Block extends StatelessWidget {
final Color color;
Block(this.color);
#override
Widget build(BuildContext context) {
return Container(height:50,width:50, color: color,);
}
}
I have the main class _MyHomePageState() where the scaffold is defined for the homepage and I have defined very widget that will go into the scaffold in a new class. Now I have to call a function/method that is defined in the main class from the onPressed of the FlatButton that is in the main class.
The function that is in the main class triggers the BottomSheet, the code for the bottom sheet is written in a new dart file.
When I write the Flat button code inside the scaffold normally and call the function it does trigger the bottom sheet.
Here's the code snippet:
class MyHomePage extends StatefulWidget {
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final GlobalKey<ScaffoldState> scaffoldKey = GlobalKey<ScaffoldState>();
///This below is the function
void openBottomSheet() {
var sheetController = scaffoldKey.currentState
.showBottomSheet((context) => BottomSheetWidget());
sheetController.closed.then((value) {
print("Bottom Sheet Closed");
});
}
#override
Widget build(BuildContext context) {
// TODO: implement build
return Scaffold(
key: scaffoldKey,
appBar: AppBar(
title: Text("Hello,World"),
),
backgroundColor: Colors.grey[800],
body: Stack(children: <Widget>[
Container(
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
color: Colors.blueGrey,
),
Column(
children: <Widget>[
TopMenu(),
ButtonClass(),
],
),
]),
);
}
}
Here is the button class:
class ButtonClass extends StatefulWidget {
_ButtonClassState createState() => _ButtonClassState();
}
class _ButtonClassState extends State<ButtonClass> {
#override
Widget build(BuildContext context) {
return Center(
child: Column(
children: <Widget>[
//Container(color: Colors.blue, child: Text("Hello,World")),
Container(
height: 50,
width:100,
margin: EdgeInsets.all(10.0),
child: FlatButton(
onPressed: (){
///And I am trying to call that function here, but is not working
_MyHomePageState().openBottomSheet();
},
child: Container(
color: Colors.red,
),
),
),
],
),
);
}
}
You can take a function parameter in your child Button Class and then pass the desired function to it from your parent class _MyHomePageState.
class MyHomePage extends StatefulWidget {
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final GlobalKey<ScaffoldState> scaffoldKey = GlobalKey<ScaffoldState>();
///This below is the function
void openBottomSheet() {
var sheetController = scaffoldKey.currentState
.showBottomSheet((context) => BottomSheetWidget());
sheetController.closed.then((value) {
print("Bottom Sheet Closed");
});
}
#override
Widget build(BuildContext context) {
// TODO: implement build
return Scaffold(
key: scaffoldKey,
appBar: AppBar(
title: Text("Hello,World"),
),
backgroundColor: Colors.grey[800],
body: Stack(children: <Widget>[
Container(
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
color: Colors.blueGrey,
),
Column(
children: <Widget>[
TopMenu(),
ButtonClass(onPressed: ()=> openBottomSheet() ),
],
),
]),
);
}
}
class ButtonClass extends StatefulWidget {
Function onPressed;
ButtonClass({this.onPressed});
_ButtonClassState createState() => _ButtonClassState();
}
class _ButtonClassState extends State<ButtonClass> {
#override
Widget build(BuildContext context) {
return Center(
child: Column(
children: <Widget>[
//Container(color: Colors.blue, child: Text("Hello,World")),
Container(
height: 50,
width:100,
margin: EdgeInsets.all(10.0),
child: FlatButton(
onPressed: () => widget.onPressed,
child: Container(
color: Colors.red,
),
),
),
],
),
);
}
}
I do believe you have to pass that function from main page to button.. something like this
class ButtonClass extends StatefulWidget {
final Function onPress;
const ButtonClass({this.onPress});
//...
//...
child: FlatButton(
onPressed: onPress,
child: Container(
color: Colors.red,
),
),
),
],
),
);
}
}
and in your main class call it
ButtonClass(onPress: ()=>openBottomSheet())