https://note.com/kitoko552/n/n7da7c55ebab6

note_n7da7c55ebab6_1.dart

DefaultTabController(
 length: _tabs.length, // This is the number of tabs.
 child: NestedScrollView(
   headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
     return <Widget>[
       SliverOverlapAbsorber(
         handle: NestedScrollView.sliverOverlapAbsorberHandleFor(context),
         child: SliverAppBar(
           title: const Text('Books'), // This is the title in the app bar.
           pinned: true,
           expandedHeight: 150.0,
           forceElevated: innerBoxIsScrolled,
           bottom: TabBar(
             tabs: _tabs.map((String name) => Tab(text: name)).toList(),
           ),
         ),
       ),
     ];
   },
   body: TabBarView(
     children: _tabs.map((String name) {
       return SafeArea(
         top: false,
         bottom: false,
         child: Builder(
           builder: (BuildContext context) {
             return CustomScrollView(
               key: PageStorageKey<String>(name),
               slivers: <Widget>[
                 SliverOverlapInjector(
                   handle: NestedScrollView.sliverOverlapAbsorberHandleFor(context),
                 ),
                 SliverPadding(
                   padding: const EdgeInsets.all(8.0),
                   sliver: SliverFixedExtentList(
                     itemExtent: 48.0,
                     delegate: SliverChildBuilderDelegate(
                       (BuildContext context, int index) {
                         return ListTile(
                           title: Text('Item $index'),
                         );
                       },
                       childCount: 30,
                     ),
                   ),
                 ),
               ],
             );
           },
         ),
       );
     }).toList(),
   ),
 ),
)