如何检索LazyRow的滚动方向

import 'package:flutter/material.dart';

class LazyRowDemo extends StatefulWidget {
  @override
  _LazyRowDemoState createState() => _LazyRowDemoState();
}

class _LazyRowDemoState extends State<LazyRowDemo> {
  ScrollController _scrollController = ScrollController();
  bool _isScrollingRight = true;

  @override
  void initState() {
    super.initState();
    _scrollController.addListener(() {
      if (_scrollController.position.userScrollDirection ==
          ScrollDirection.reverse) {
        setState(() {
          _isScrollingRight = true;
        });
      } else if (_scrollController.position.userScrollDirection ==
          ScrollDirection.forward) {
        setState(() {
          _isScrollingRight = false;
        });
      }
    });
  }

  @override
  void dispose() {
    _scrollController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('LazyRow Demo'),
      ),
      body: ListView(
        children: [
          LazyRow(
            controller: _scrollController,
            children: [
              // 子元素
              // ...
            ],
          ),
          SizedBox(height: 20),
          Center(
            child: Text(
              _isScrollingRight ? '正在向右滚动' : '正在向左滚动',
              style: TextStyle(fontSize: 18),
            ),
          ),
        ],
      ),
    );
  }
}