flutter multiple pageview and controller

Question

I have two pageviews:

• pageview0 has 3 pages: 1, 2, 3
• pageview1 has 3 pages: A, B, C

Only one pageview is shown at a time, and I want to switch between them when I press a 'switch' button on AppBar.

What I want:

If I'm at pageview0 page2 and press the switch button, then I want to see pageview1 page A.

But the below code shows pageview1 page B (the page with same index). I also tried to use two PageControllers instead of one, but the behavior is same. How can I control what page to show when there's multiple PageViews and switching between them?

My code:

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

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

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  List<String> pageview0 = ["1", "2", "3"];
  List<String> pageview1 = ["A", "B", "C"];
  int pageViewIndex = 0;

  // Try single controller.
  PageController controller;
  // Try multiple controller.
  List<PageController> controllers;

  @override
  void initState() {
    super.initState();
    controller = PageController(initialPage: 0);  // pageview0 and pageview1
    controllers = [];
    controllers.add(PageController(initialPage: 0));  // pageview0
    controllers.add(PageController(initialPage: 0));  // pageview1
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        actions: <Widget>[
          IconButton(icon: const Icon(Icons.navigate_next), onPressed: () {
            setState(() {
              if (pageViewIndex == 0) pageViewIndex = 1;
              else pageViewIndex = 0;
            });
          },)
        ],
      ),
      body: PageView.builder(
        itemBuilder: (context, page) {
          if (pageViewIndex == 0) return Center(child: Text(pageview0[page]));
          else return Center(child: Text(pageview1[page]));
        },
        itemCount: 3,

        // single controller
//        controller: controller,

        // Multiple controller
        controller: (pageViewIndex == 0)? controllers[0] : controllers[1],
      ),
    );
  }
}

Answer 1

Based on Taufik's comment, I changed to IndexedStack and works well.

Here's the new code:

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

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

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  List<String> pageview0 = ["1", "2", "3"];
  List<String> pageview1 = ["A", "B", "C"];
  int pageViewIndex = 0;

  // Try single controller.
  PageController controller;
  // Try multiple controller.
  List<PageController> controllers;

  @override
  void initState() {
    super.initState();
    controller = PageController(initialPage: 0);  // pageview0 and pageview1
    controllers = [];
    controllers.add(PageController(initialPage: 0));  // pageview0
    controllers.add(PageController(initialPage: 0));  // pageview1
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        actions: <Widget>[
          IconButton(icon: const Icon(Icons.navigate_next), onPressed: () {
            setState(() {
              if (pageViewIndex == 0) pageViewIndex = 1;
              else pageViewIndex = 0;
            });
          },)
        ],
      ),
      body: IndexedStack(
        index: pageViewIndex,
        children: <Widget> [
          PageView.builder(
            itemBuilder: (context, page) {
              return Center(child: Text(pageview0[page]));
            },
            itemCount: 3,
            controller: controllers[0],
          ),
          PageView.builder(
            itemBuilder: (context, page) {
              return Center(child: Text(pageview1[page]));
            },
            itemCount: 3,
            controller: controllers[1],
          ),
        ],
      ),
    );
  }
}