lib/main.dart

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';


void main() {
runApp(MaterialApp(
    home: MyPageView(),
  ));
}

class MyPageView extends StatefulWidget {
  MyPageView({Key key}) : super(key: key);

  _MyPageViewState createState() => _MyPageViewState();
}

class _MyPageViewState extends State {
  PageController _pageController;

  @override
  void initState() {
    super.initState();
    _pageController = PageController();
  }

  @override
  void dispose() {
    _pageController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: PageView(
          controller: _pageController,
          children: [
            Container(
              color: Colors.red,
              child: Center(
                child: RaisedButton(
                  color: Colors.white,
                  onPressed: () {
                    if (_pageController.hasClients) {
                      _pageController.animateToPage(
                        1,
                        duration: const Duration(milliseconds: 400),
                        curve: Curves.easeInOut,
                      );
                    }
                  },
                  child: Text('Next'),
                ),
              ),
            ),
            Container(
              color: Colors.blue,
              child: Center(
                child: RaisedButton(
                  color: Colors.white,
                  onPressed: () {
                    if (_pageController.hasClients) {
                      _pageController.animateToPage(
                        0,
                        duration: const Duration(milliseconds: 400),
                        curve: Curves.easeInOut,
                      );
                    }
                  },
                  child: Text('Previous'),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}