未反映在flutter中添加到列表上的更改

// 假设你有一个列表
List<String> myList = ['Item 1', 'Item 2'];

// 修改列表并更新UI
void addItem() {
  setState(() {
    myList = [...myList, 'New Item']; // 创建一个新的列表实例
  });
}

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('List Example')),
        body: ListExample(),
      ),
    );
  }
}

class ListExample extends StatefulWidget {
  @override
  _ListExampleState createState() => _ListExampleState();
}

class _ListExampleState extends State<ListExample> {
  List<String> myList = ['Item 1', 'Item 2'];

  void addItem() {
    setState(() {
      myList = [...myList, 'New Item'];
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Expanded(
          child: ListView.builder(
            itemCount: myList.length,
            itemBuilder: (context, index) {
              return ListTile(title: Text(myList[index]));
            },
          ),
        ),
        ElevatedButton(
          onPressed: addItem,
          child: Text('Add Item'),
        ),
      ],
    );
  }
}