flutter实现底部导航栏切换

本文实例为大家分享了flutter实现底部导航栏切换的具体代码，供大家参考，具体内容如下

思路：MaterialApp是提供了bottomnavigationbar的，可以使用，这个已经提供了的widget，再利用每次点击tab的时候使用set state方法来更新屏幕，切换中间的body的widget；
main文件：

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_app1/MyBottomNavigationBar.dart';

void main(){
  runApp(new MyApp());
}
class MyApp extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    // throw UnimplementedError();
    return new MaterialApp(
      title:" MyNavigationBar",
      home: new MyBottomNavigationBar(),
    );
  }

}

MyBottomNavigationBar()：

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_app1/pages/AddScreen.dart';
import 'package:flutter_app1/pages/HomeScreen.dart';
import 'package:flutter_app1/pages/PersonScreen.dart';

class MyBottomNavigationBar extends StatefulWidget{
  @override
  MyNavigationBarState createState() {
    // TODO: implement createState
    // throw UnimplementedError();
    return new MyNavigationBarState();
  }

}
class MyNavigationBarState extends State<MyBottomNavigationBar>{
 List<Widget> pagesList=[];
 int cunrrentIndex=0;

 @override
  void initState() {
   pagesList=pagesList..add(new HomeScreen())
       ..add(new AddScreen())
       ..add(new PersonScreen());
  }

  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    // throw UnimplementedError();
    return new Scaffold(
      appBar: new AppBar(
        title: new Text("MyNavigationBar"),
      ),
      body: pagesList[cunrrentIndex],
      bottomNavigationBar: new BottomNavigationBar(
        items: [
          new BottomNavigationBarItem(
            icon: new Icon(Icons.home),
            label:"Home"
          ),
          new BottomNavigationBarItem(
              icon: new Icon(Icons.add),
              label:"Add"
          ),
          new BottomNavigationBarItem(
              icon: new Icon(Icons.person),
              label:"Person"
          )
        ],
        onTap:(index){
          setState(() {
            cunrrentIndex=index;
          });
        },
        currentIndex: cunrrentIndex,
      )
    );
  }

}

addScreen：

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

class AddScreen extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    // throw UnimplementedError();
    return new Scaffold(
      appBar: new AppBar(
        title: new Text("AddPage"),
      ),
      body: new Center(
        child: new Text("Add"),
      ),
    );
  }

}

HomeScreen

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

class HomeScreen extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    // throw UnimplementedError();
    return new Scaffold(
      appBar: new AppBar(
        title: new Text("HomePage"),
      ),
      body: new Center(
        child:Image.asset("images/cat.png"),
      ),
    );
  }

}

PersonScreen ：

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

class PersonScreen extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    // throw UnimplementedError();
    return new Scaffold(
      appBar: new AppBar(
        title: new Text("PersonPage"),
      ),
      body: new Center(
        child: new Text("Person"),
      ),
    );
  }

}

最终效果：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持自由互联。