return Scaffold(
      body: NestedScrollView(
        headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
          return <Widget>[
            SliverToBoxAdapter(
              child: Container(
                height: 80,
                width: MediaQuery.of(context).size.width,
                decoration: BoxDecoration(
                  borderRadius: BorderRadius.only(
                    bottomLeft: Radius.circular(20),
                    bottomRight: Radius.circular(20),
                  ),
                  color: Colors.red,
                ),
                child: Center(
                  child: Text('Hello'),
                ),
              ),
            )
          ];
        },
        body: Center(
          child: Text("Sample Text"),
        ),
      ),
    );