Flutter: Listview在添加项目到列表并滚动到末尾后，获取滚动控制器的完整大小

import 'package:flutter/material.dart';

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

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('My Listview'),
      ),
      body: ListView.builder(
        controller: _scrollController,
        itemCount: items.length,
        itemBuilder: (context, index) {
          return ListTile(
            title: Text(items[index]),
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          setState(() {
            items.add('New Item');
          });
          // 滚动到末尾
          _scrollController.jumpTo(_scrollController.position.maxScrollExtent);
        },
        child: Icon(Icons.add),
      ),
    );
  }
}