appbar导航

import 'package:flutter/material.dart';
import 'dart:ui';

void main()=>runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: HomePage(),
    );
  }
}

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> with SingleTickerProviderStateMixin{
  TabController _controller;
  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }
  @override
  void initState() {
    super.initState();
    _controller = TabController(length: 3, vsync: this);
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Run for better future'),
        bottom:TabBar(
            tabs: <Widget>[
          Tab(icon: Icon(Icons.accessibility),),
          Tab(icon: Icon(Icons.description),),
          Tab(icon: Icon(Icons.accessibility_new),),
        ],
          controller: _controller,
        ),
      ),
      body: TabBarView(
        controller: _controller,
        children: <Widget>[
          Center(
            child: Text(
              'Realize your value with your life',
              style: TextStyle(
                color: Colors.green,
                fontWeight: FontWeight.bold,
                fontSize: 26,
              ),
            ),
          ),
          Center(
            child: Text(
              'Play hard work hard',
              style: TextStyle(
                color: Colors.green,
                fontWeight: FontWeight.bold,
                fontSize: 26,
              ),
            ),
          ),
          Center(
            child: Text(
              'Magic of everthing is hope',
              style: TextStyle(
                color: Colors.green,
                fontWeight: FontWeight.bold,
                fontSize: 26,
              ),
            ),
          ),
        ],
      ),
    );
  }
}