Замените виджет AppBar своим собственным виджетом ниже:
class App extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: DefaultTabController(
length: 2,
child: Scaffold(
bottomNavigationBar: TabBar(
labelColor: Colors.orange,
unselectedLabelColor: Colors.grey,
indicatorSize: TabBarIndicatorSize.tab,
indicatorColor: Colors.orange,
tabs: [
Tab(
icon: Icon(Icons.add),
),
Tab(
icon: Icon(Icons.search),
),
],
),
body: Column(
children: <Widget>[
// Remove the AppBar code below and put your "cab" widget
AppBar(
primary: true,
title: Text('Here is your cab'),
centerTitle: true,
backgroundColor: Colors.orange,
),
Expanded(
child: TabBarView(
children: [
Icon(Icons.add),
Icon(Icons.search),
],
),
),
],
),
),
),
);
}
}