答案 0 :(得分:0)
你还没有定义 Appbar 中的 TabBar 和 TabBarView 正文中的标签内容:
Widget build(BuildContext context) {
return DefaultTabController(
initialIndex: 1,
length: 3,
child: Scaffold(
appBar: AppBar(
title: const Text('TabBar Widget'),
bottom: const TabBar(
tabs: <Widget>[
Tab(
icon: Icon(Icons.cloud_outlined),
),
Tab(
icon: Icon(Icons.beach_access_sharp),
),
Tab(
icon: Icon(Icons.brightness_5_sharp),
),
],
),
),
body: const TabBarView(
children: <Widget>[
Center(
child: Text('It\'s cloudy here'),
),
Center(
child: Text('It\'s rainy here'),
),
Center(
child: Text('It\'s sunny here'),
),
],
),
),
);
}