zhiying_comm/lib/util/sliver_tab_bar_delegate.dart

import 'package:flutter/material.dart';

class SliverTabBarDelegate extends SliverPersistentHeaderDelegate {
  final TabBar widget;

  const SliverTabBarDelegate(this.widget) : assert(widget != null);

  @override
  Widget build(BuildContext context, double shrinkOffset, bool overlapsContent) {
    return this.widget;
  }

  @override
  bool shouldRebuild(SliverTabBarDelegate oldDelegate) {
    return false;
  }

  @override
  double get maxExtent => widget.preferredSize.height;

  @override
  double get minExtent => widget.preferredSize.height;
}