how to stop navigator to reload view?

Question

I'm new to flutter and have a question about navigator. I have 2 views one called Home and List. I created a drawer that is persistent in these two views. In each view I'm creating a reference to Firebase using FutureBuilder. The problem I'm running into is that every time I go to either Home or List initState is being called again. I believe the problem comes from selecting the page from the drawer. My question How can I still move to different pages without having to called InitState everytime I change screens.

title: Text('Go to page 1'),
        onTap: () {
          Navigator.of(context)
              .push(MaterialPageRoute(builder: (context) => Listdb()));

This is where I think the screen rebuilds itself. Is there a way to avoid rebuilding? Thank you for your help!

Answer 1

You can use the AutomaticKeepAliveClientMixin to prevent reloading everytime you change page, combining with PageView for better navigation. I'll included an example here:

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final PageController _pageController = PageController();

  Widget build(BuildContext context) {
    return Scaffold(
      drawer: Drawer(
        child: ListView(
          padding: EdgeInsets.zero,
          children: <Widget>[
            DrawerHeader(
              child: Text('Drawer Header'),
              decoration: BoxDecoration(
                color: Colors.blue,
              ),
            ),
            ListTile(
              title: Text('Item 1'),
              onTap: () {
                _pageController.jumpToPage(0);
                Navigator.pop(context);
              },
            ),
            ListTile(
              title: Text('Item 2'),
              onTap: () {
                _pageController.jumpToPage(1);
                Navigator.pop(context);
              },
            ),
          ],
        ),
      ),
      body: PageView(
        controller: _pageController,
        children: <Widget>[
          PageOne(),
          PageTwo(),
        ],
      ),
    );
  }
}

class PageOne extends StatefulWidget {
  @override
  _PageOneState createState() => _PageOneState();
}

class _PageOneState extends State<PageOne> with AutomaticKeepAliveClientMixin {
  @override
  void initState() {
    print("From PageOne - This will only print once");
    super.initState();
  }

  @override
  bool get wantKeepAlive => true;

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return Scaffold(
      backgroundColor: Colors.red,
    );
  }
}

class PageTwo extends StatefulWidget {
  @override
  _PageTwoState createState() => _PageTwoState();
}

class _PageTwoState extends State<PageTwo> with AutomaticKeepAliveClientMixin {
  @override
  void initState() {
    print("From PageTwo - This will only print once");
    super.initState();
  }

  @override
  bool get wantKeepAlive => true;

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return Scaffold(
      backgroundColor: Colors.blue,
    );
  }
}