CODE EXAMPLE FOR DART

flutter sliver persistent header example

class Delegate extends SliverPersistentHeaderDelegate {
  final Color backgroundColor;
  final String headerTitle;

  Delegate(this.backgroundColor, this.headerTitle);

  @override
  Widget build(
      BuildContext context, double shrinkOffset, bool overlapsContent) {
    return Container(
      color: backgroundColor,
      child: Center(
        child: Text(
          headerTitle,
          style: const TextStyle(
            color: Colors.black,
            fontSize: 20,
          ),
        ),
      ),
    );
  }

  @override
  double get maxExtent => 150;

  @override
  double get minExtent => 60;

  @override
  bool shouldRebuild(SliverPersistentHeaderDelegate oldDelegate) {
    return true;
  }