在颤动中向BottomNavigationBar添加指示器

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('BottomNavigationBar with Indicator'),
        ),
        body: Center(
          child: Text('Content goes here'),
        ),
        bottomNavigationBar: CustomBottomNavigationBar(),
      ),
    );
  }
}

class CustomBottomNavigationBar extends StatefulWidget {
  @override
  _CustomBottomNavigationBarState createState() =>
      _CustomBottomNavigationBarState();
}

class _CustomBottomNavigationBarState extends State<CustomBottomNavigationBar> {
  int _currentIndex = 0;

  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: BoxDecoration(
        color: Colors.white,
        boxShadow: [
          BoxShadow(
            color: Colors.grey.withOpacity(0.3),
            spreadRadius: 2,
            blurRadius: 5,
            offset: Offset(0, 3),
          ),
        ],
      ),
      child: BottomNavigationBar(
        currentIndex: _currentIndex,
        onTap: (index) {
          setState(() {
            _currentIndex = index;
          });
        },
        items: [
          BottomNavigationBarItem(
            icon: Icon(Icons.home),
            label: 'Home',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.search),
            label: 'Search',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.person),
            label: 'Profile',
          ),
        ],
      ),
    );
  }
}