How to make a top tab bar with CupertinoSliverNavigationBar Flutter - flutter

Question

I use CupertinoSliverNavigationBar, how can I add a tab bar below the title that is fixed to scroll?
My current code :
class SearchView extends StatefulWidget {
#override
_SearchViewState createState() => _SearchViewState();
}
class _SearchViewState extends State<SearchView> {
#override
Widget build(BuildContext context) {
return CupertinoPageScaffold(
child: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
CupertinoSliverNavigationBar(
backgroundColor: Colors.white,
border: Border.all(width: 0.0, color: const Color(0xFFFFFFFF)),
leading: Material(
child: GestureDetector(
onTap: () => Navigator.of(context).pop(),
child: Icon(
IconData(
0xe904,
fontFamily: 'icomoon',
),
color: Colors.black,
size: 25.0,
),
),
),
largeTitle: Text('Discover'),
)
];
},
body: Scaffold(
backgroundColor: Colors.white,
body: Container(),
),
),
);
}
}
Like on the attached picture :
Of course, if there is a solution that works without the Cupertino widgets, but that still respects the design, I'm interested.

Answer 1

You can use NeverScrollableScrollPhysics to ensure that the height of the CupertinoSliverNavigationBar remains fixed:
CupertinoPageScaffold(
child: CustomScrollView(
physics: const NeverScrollableScrollPhysics(), // add
slivers: [
CupertinoSliverNavigationBar(
middle: Text(
testNumber,
style: const TextStyle(
color: CupertinoColors.systemPink
),
),
largeTitle: const CircleAvatar(
backgroundColor: CupertinoColors.systemGreen,
child: Text("1"),
),
),
SliverFillRemaining(
child: PageView.builder(
itemBuilder: (context, index) {
return Text("$index");
},
),
)
],
)
);