How do I initialize data with the Provider in flutter - flutter

Question

This is code：
main
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return ChangeNotifierProvider<Something>(
create: (_) => Something(),
child: Consumer<Something>(
builder: (BuildContext context, Something value, Widget child) {
return MaterialApp(
title: 'Flutter Demo',
home: MyHomePage(),
);
},
),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key}) : super(key: key);
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
String mockData = '';
#override
void initState() {
super.initState();
initData();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('demo'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'moceData:$mockData',
),
Text(
'${Provider.of<Something>(context).count}',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: () {
Navigator.push(context, MaterialPageRoute(builder: (_) {
return SecondPage();
}));
},
child: Icon(Icons.add),
),
);
}
initData() {
Future.delayed(Duration(seconds: 1), () {
mockData = 'mock 123';
setState(() {});
});
}
}
SecondPage
class SecondPage extends StatefulWidget {
#override
_SecondPageState createState() => _SecondPageState();
}
class _SecondPageState extends State<SecondPage> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
child: Center(
child: GestureDetector(
onTap: () {
Provider.of<Something>(context, listen: false).doSomething();
},
child: Text('click'),
),
),
),
);
}
}
Something
class Something extends ChangeNotifier {
var count =0;
void doSomething() {
print('doSomething');
count++;
notifyListeners();
}
}
when we open this app, MyHomePage request data in initState，
when we push secondPage，we click ‘click’ btn，We want the first page to retrieve the data（iniData()）.
when we click ,notifiyListeners() and _MyHomePageState build()is called, but initState（）is not，so
how to do？we can invoke initData again.
Similar situation：
1.We have changed the language on other pages. The data on the home page needs to re-request the language interface of the response.
2.After the user logs in successfully, refresh the user inventory, the inventory page already exists

Answer 1

Try this :
setState(() {
mockData = 'mock 123';
});
But here you are not initializing data to use it with Provider, if you are looking to get data ( i mean mockData var ) with Provider , you can do that :
in Something class you add this:
String mockData="123";
String get mockdata => mockData;
and then in the HomePage you access this data using the Provider :
Provider.of<Something>(context, listen:false).mockdata;
i hope i could help you.. good luck !

Answer 2

sorry，Maybe I didn't describe the problem clearly enough, but I have found a solution now.
use
ChangeNotifierProxyProvider<Foo, MyChangeNotifier>(
create: (_) => MyChangeNotifier(),
update: (_, foo, myNotifier) => myNotifier
..foo = foo,
child: ...
);
/// A [ChangeNotifierProvider] that builds and synchronizes a [ChangeNotifier]
/// from values obtained from other providers.
Thanks