Flutter -如何制作弯曲类型的自定义底部导航栏

import 'package:flutter/material.dart';

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

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  int _selectedIndex = 0;

  void _onItemTapped(int index) {
    setState(() {
      _selectedIndex = index;
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Flutter Custom Bottom Navigation Bar'),
        ),
        body: Center(
          child: _getPageContent(_selectedIndex),
        ),
        bottomNavigationBar: BottomNavigationBar(
          type: BottomNavigationBarType.shifting,
          currentIndex: _selectedIndex,
          onTap: _onItemTapped,
          items: [
            BottomNavigationBarItem(
              icon: Icon(Icons.home),
              title: Text('Home'),
              backgroundColor: Colors.red,
            ),
            BottomNavigationBarItem(
              icon: Icon(Icons.search),
              title: Text('Search'),
              backgroundColor: Colors.green,
            ),
            BottomNavigationBarItem(
              icon: Icon(Icons.person),
              title: Text('Profile'),
              backgroundColor: Colors.blue,
            ),
          ],
        ),
      ),
    );
  }

  Widget _getPageContent(int index) {
    switch (index) {
      case 0:
        return Text('Home Page');
      case 1:
        return Text('Search Page');
      case 2:
        return Text('Profile Page');
      default:
        return Text('Unknown Page');
    }
  }
}