使用具有各种条件的按钮控制PageView

import 'package:flutter/material.dart';

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

class _MyPageState extends State<MyPage> {
  PageController _pageController = PageController();
  int _currentPageIndex = 0;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('PageView with Conditional Buttons'),
      ),
      body: Column(
        children: [
          Expanded(
            child: PageView(
              controller: _pageController,
              onPageChanged: (index) {
                setState(() {
                  _currentPageIndex = index;
                });
              },
              children: [
                Container(
                  color: Colors.red,
                  child: Center(
                    child: Text('Page 1'),
                  ),
                ),
                Container(
                  color: Colors.green,
                  child: Center(
                    child: Text('Page 2'),
                  ),
                ),
                Container(
                  color: Colors.blue,
                  child: Center(
                    child: Text('Page 3'),
                  ),
                ),
              ],
            ),
          ),
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              FlatButton(
                onPressed: () {
                  _pageController.animateToPage(
                    0,
                    duration: Duration(milliseconds: 500),
                    curve: Curves.ease,
                  );
                },
                color: _currentPageIndex == 0 ? Colors.grey : Colors.white,
                child: Text('Button 1'),
              ),
              FlatButton(
                onPressed: () {
                  _pageController.animateToPage(
                    1,
                    duration: Duration(milliseconds: 500),
                    curve: Curves.ease,
                  );
                },
                color: _currentPageIndex == 1 ? Colors.grey : Colors.white,
                child: Text('Button 2'),
              ),
              FlatButton(
                onPressed: () {
                  _pageController.animateToPage(
                    2,
                    duration: Duration(milliseconds: 500),
                    curve: Curves.ease,
                  );
                },
                color: _currentPageIndex == 2 ? Colors.grey : Colors.white,
                child: Text('Button 3'),
              ),
            ],
          ),
        ],
      ),
    );
  }
}

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