flutter开发实战-设置bottomNavigationBar中间按钮悬浮效果-编程知识

flutter开发实战-设置bottomNavigationBar中间按钮悬浮效果

flutter开发实战-设置bottomNavigationBar中间按钮悬浮的效果

在使用tabbar时候，可以使用bottomNavigationBar来设置中间凸起的按钮，如下

一、效果图

中间按钮凸起的效果图如下

在这里插入图片描述

二、实现代码

我们使用BottomAppBar
一个容器，通常与[Sscaffold.bottomNavigationBar]一起使用。

使用的示例代码

Scaffold(bottomNavigationBar: BottomAppBar(color: Colors.white,child: bottomAppBarContents,),floatingActionButton: const FloatingActionButton(onPressed: null),)

设置中间的凸起按钮，可以设置BottomAppBar的shape为：CircularNotchedRectangle，中间悬浮按钮嵌入BottomAppBar
设置notchMargin缺口边距。
设置floatingActionButtonLocation：FloatingActionButtonLocation.centerDocked,//放在中间

完整代码如下

import 'package:flutter/material.dart';class TabDemoPage extends StatefulWidget {const TabDemoPage({super.key});@overrideState<TabDemoPage> createState() => _TabDemoPageState();
}class _TabDemoPageState extends State<TabDemoPage> {List<String> pageTitles = [];List<Widget> pageChildren = [];int currentIndex = 0;@overridevoid initState() {// TODO: implement initStatepageTitles = ["首页","我的"];pageChildren = [Container(color: Colors.lightBlueAccent,),Container(color: Colors.pinkAccent,)];super.initState();}@overridevoid dispose() {// TODO: implement disposesuper.dispose();}Widget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text(pageTitles[currentIndex]),///导航栏标题centerTitle: true,///导航栏标题居中显示（IOS默认居中，Android默认靠左）),body: pageChildren[currentIndex],bottomNavigationBar: BottomAppBar(shape: CircularNotchedRectangle(), ///中间悬浮按钮嵌入BottomAppBarnotchMargin: 10,///缺口边距child: Row(mainAxisAlignment: MainAxisAlignment.spaceAround,children: [IconButton(icon: Icon(Icons.home),onPressed: (){setState(() {currentIndex = 0;});}),IconButton(icon: Icon(Icons.person),onPressed: (){setState(() {currentIndex = 1;});}),],),),floatingActionButton: FloatingActionButton(foregroundColor: Colors.white,elevation: 10.0,///阴影onPressed: (){},child: Icon(Icons.add),),floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,//放在中间);}
}