[Flutter] Use stream in provider with flutter

I make a simple example to understand using Stream with Provider pattern in flutter.

I do not know How can I change stream value in this case ? - when I click Add icon, the value will be add, count value is increased (like Sink.add)

Please help me understand using Stream with Provider.

Thanks a lot!!!

Screen:



this is my code:

import 'dart:async';
import 'dart:convert';

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'packagerovider/provider.dart';

// Main app and Pages for Tab Layout
void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MultiProvider(
providers: [
StreamProvider(
create: (_) => EventProvider().intStream(), initialData: 0),
],
child: DefaultTabController(
length: 1,
child: DefaultTabController(
length: 1,
child: Scaffold(
appBar: AppBar(
title: Text("Provider Demo"),
bottom: TabBar(
tabs: [
Tab(icon: Icon(Icons.add)),
],
),
),
body: TabBarView(
children: [
MyEventPage(),
],
),
),
))));
}
}

// Event page (counting)
class MyEventPage extends StatelessWidget {
@override
Widget build(BuildContext context) {
var _value = Provider.of<int>(context);
return Container(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text('StreamProvider Example'),
SizedBox(height: 50),
Text('${_value.toString()}',
style: Theme.of(context).textTheme.display1)
],
)),
Align(
alignment: Alignment.bottomRight,
child: RaisedButton(
onPressed: () {
EventProvider().add();
},
child: Icon(Icons.add),
),
)
],
));
}
}

// User List Page

// EventProvider (Stream)
class EventProvider {
StreamController<int> sc = StreamController();
int count = 0;

Stream<int> intStream() {
// return Stream<int>.periodic(interval, (int _count) => _count++);
return sc.stream;
}

add () {
count++;
sc.sink.add;
}
}

Continue reading...