Flutter:滑动时在pageview中添加新页面

import 'package:flutter/material.dart';

class MyPage extends StatefulWidget {
  @override
  _MyPageState createState() => _MyPageState();
}

class _MyPageState extends State<MyPage> {
  PageController _pageController;
  List<Widget> _pages = [];

  @override
  void initState() {
    super.initState();
    _pageController = PageController();
    _pages = [
      Container(color: Colors.red),
      Container(color: Colors.blue),
      Container(color: Colors.green),
    ];
  }

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('PageView Example'),
      ),
      body: PageView.builder(
        controller: _pageController,
        itemBuilder: (BuildContext context, int index) {
          return _pages[index % _pages.length];
        },
        itemCount: _pages.length,
        onPageChanged: (int index) {
          // 当滑动到最后一页时，添加新的页面
          if (index == _pages.length - 1) {
            setState(() {
              _pages.add(Container(color: Colors.yellow));
            });
          }
        },
      ),
    );
  }
}

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