在顶部添加新项目时保持ListView中的滚动位置

import 'package:flutter/material.dart';

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

class _MyListViewState extends State<MyListView> {
  List<String> items = [];
  ScrollController _scrollController;

  @override
  void initState() {
    super.initState();
    _scrollController = ScrollController();
  }

  void addItem(String item) {
    setState(() {
      items.insert(0, item); // 在顶部添加新项目
    });
    // 恢复滚动位置
    Future.delayed(Duration.zero, () {
      _scrollController.jumpTo(_scrollController.position.minScrollExtent);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('ListView Example'),
      ),
      body: ListView.builder(
        controller: _scrollController,
        itemCount: items.length,
        itemBuilder: (context, index) {
          return ListTile(title: Text(items[index]));
        },
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          addItem('New Item');
        },
        child: Icon(Icons.add),
      ),
    );
  }

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

import 'package:flutter/material.dart';

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

class _MyListViewState extends State<MyListView> {
  List<String> items = [];
  int _scrollIndex = 0;

  void addItem(String item) {
    setState(() {
      items.insert(0, item); // 在顶部添加新项目
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('ListView Example'),
      ),
      body: ListView.builder(
        itemCount: items.length,
        itemBuilder: (context, index) {
          if (index == 0) {
            _scrollIndex = index; // 保存当前滚动位置
          }
          return ListTile(title: Text(items[index]));
        },
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          addItem('New Item');
        },
        child: Icon(Icons.add),
      ),
    );
  }
}