Flutter Listview过滤器未在类型上重建列表

import 'package:flutter/material.dart';

class MyListView extends StatefulWidget {
  @override
  _MyListViewState createState() => _MyListViewState();
}

class _MyListViewState extends State<MyListView> {
  List<String> originalList = [
    'Apple',
    'Banana',
    'Cherry',
    'Durian',
    'Elderberry',
  ];

  String filter = '';

  List<String> get filteredList {
    return originalList
        .where((item) => item.toLowerCase().contains(filter.toLowerCase()))
        .toList();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('ListView Filter'),
      ),
      body: Column(
        children: [
          TextField(
            onChanged: (value) {
              setState(() {
                filter = value;
              });
            },
            decoration: InputDecoration(
              labelText: 'Filter',
            ),
          ),
          Expanded(
            child: ListView.builder(
              itemCount: filteredList.length,
              itemBuilder: (context, index) {
                return ListTile(
                  title: Text(filteredList[index]),
                );
              },
            ),
          ),
        ],
      ),
    );
  }
}

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