如何将Flutter选项卡栏指示器更改为与google play商店完全相同

import 'package:flutter/material.dart';

class CustomTabIndicator extends Decoration {
  @override
  BoxPainter createBoxPainter([VoidCallback? onChanged]) {
    return _CustomPainter(this, onChanged);
  }
}

class _CustomPainter extends BoxPainter {
  final CustomTabIndicator decoration;

  _CustomPainter(this.decoration, VoidCallback? onChanged)
      : super(onChanged);

  @override
  void paint(Canvas canvas, Offset offset, ImageConfiguration configuration) {
    final Rect rect = offset & configuration.size!;
    final Paint paint = Paint();
    paint.color = Colors.blue; // 设置指示器颜色
    paint.style = PaintingStyle.fill;
    canvas.drawRect(rect, paint);
  }
}

class MyTabBar extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return DefaultTabController(
      length: 3,
      child: Scaffold(
        appBar: AppBar(
          title: Text('My App'),
          bottom: TabBar(
            indicator: CustomTabIndicator(), // 使用自定义的选项卡指示器
            tabs: [
              Tab(text: 'Tab 1'),
              Tab(text: 'Tab 2'),
              Tab(text: 'Tab 3'),
            ],
          ),
        ),
        body: TabBarView(
          children: [
            // 每个选项卡对应的内容
            Container(
              child: Text('Tab 1 Content'),
            ),
            Container(
              child: Text('Tab 2 Content'),
            ),
            Container(
              child: Text('Tab 3 Content'),
            ),
          ],
        ),
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: MyTabBar(),
  ));
}