Flutter（十四）：AppBar

import 'package:flutter/material.dart';

import 'package:app03/pages/home/HomePage.dart';
import 'package:app03/pages/category/CategoryPage.dart';
import 'package:app03/pages/settings/SettingsPage.dart';

class TabsPage extends StatefulWidget {
  final int index;
  TabsPage({Key key, this.index = 0}) : super(key: key);
  @override
  _TabsPageState createState() => _TabsPageState(this.index);
}

class _TabsPageState extends State<TabsPage> {
  int currentIndex = 0;

  _TabsPageState(index) {
    this.currentIndex = index;
  }

  List listTabs = [
    HomePage(),
    CategoryPage(),
    SettingsPage(),
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('flutter 标题'),
        centerTitle: true,
        backgroundColor: Colors.pink,
        leading: IconButton(
          icon: Icon(Icons.menu),
          onPressed: () {
            print('menu');
          },
        ),
        actions: <Widget>[
          IconButton(
            icon: Icon(Icons.search),
            onPressed: () {
              print('search');
            },
          ),
          IconButton(
            icon: Icon(Icons.settings),
            onPressed: () {
              print('settings');
            },
          )
        ],
      ),
      body: this.listTabs[this.currentIndex],
      bottomNavigationBar: BottomNavigationBar(
        currentIndex: this.currentIndex,
        iconSize: 30.0,
        type: BottomNavigationBarType.fixed,
        onTap: (index) {
          setState(() {
            this.currentIndex = index;
          });
        },
        items: [
          BottomNavigationBarItem(
            icon: Icon(Icons.home),
            title: Text('首页'),
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.category),
            title: Text('分类'),
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.settings),
            title: Text('设置'),
          ),
        ],
      ),
    );
  }
}