Попробуйте это.
import 'package:flutter/material.dart';
void main() => runApp(new MaterialApp(
home: new MainPage(),
));
class MainPage extends StatefulWidget {
@override
_MainPageState createState() => new _MainPageState();
}
class _MainPageState extends State<MainPage> {
int count = 0;
bool isMultiSelectStarted = false;
void onMultiSelectStarted(int count, bool isMultiSelect) {
print('Count: $count isMultiSelectStarted: $isMultiSelect');
}
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
backgroundColor: Colors.blue,
title: new Text('Home'),
),
body: new Center(
child: new RaisedButton(
child: new Text('Go to SecondPage'),
onPressed: () {
Navigator.of(context).push(
new MaterialPageRoute(
builder: (context) {
return new SecondPage(onMultiSelectStarted);
},
),
);
},
),
),
);
}
}
class SecondPage extends StatefulWidget {
int count = 1;
bool isMultiSelectStarted = true;
final Function multiSelect;
SecondPage(this.multiSelect);
@override
_SecondPageState createState() => new _SecondPageState();
}
class _SecondPageState extends State<SecondPage> {
@override
Widget build(BuildContext context) {
return new Center(
child: new RaisedButton(
child: new Text('Pass data to MainPage'),
onPressed: () {
widget.multiSelect(widget.count, widget.isMultiSelectStarted);
},
),
);
}
}