import 'package:curved_navigation_bar/curved_navigation_bar.dart';

import 'package:flutter/material.dart';

​

void main() {

  runApp(MyApp());

}

​

class MyApp extends StatelessWidget {

  // This widget is the root of your application.

  @override

  Widget build(BuildContext context) {

    return MaterialApp(

      title: 'Flutter Demo',

      theme: ThemeData(

        primarySwatch: Colors.blue,

        visualDensity: VisualDensity.adaptivePlatformDensity,

      ),

      home: MyHomePage(title: 'Flutter Demo Home Page'),

    );

  }

}

​

class MyHomePage extends StatefulWidget {

  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

​

  @override

  _MyHomePageState createState() => _MyHomePageState();

}

​

class _MyHomePageState extends State<MyHomePage> {

  int _page = 0;

  GlobalKey _bottomNavigationKey = GlobalKey();

​

  Widget bodyFunction() {

    switch (_page) {

      case 0:

        return Container(color: Colors.red);

        break;

      case 1:

        return Container(color: Colors.blue);

        break;

      case 2:

        return Container(color: Colors.orange);

        break;

      default:

        return Container(color: Colors.white);

        break;

    }

  }

​

  @override

  Widget build(BuildContext context) {

    return Scaffold(

      body: bodyFunction(),

      bottomNavigationBar: CurvedNavigationBar(

        key: _bottomNavigationKey,

        index: 0,

        height: 75.0,

        items: <Widget>[

          Icon(Icons.list, size: 30),

          Icon(Icons.people, size: 30),

          Icon(Icons.launch, size: 30),

        ],

        color: Colors.white,

        buttonBackgroundColor: Colors.white,

        backgroundColor: Colors.blueAccent,

        animationCurve: Curves.easeInOut,

        animationDuration: Duration(milliseconds: 300),

        onTap: (index) {

          setState(() {

            _page = index;

          });

        },

      ),

    );

  }

}