当将TextField聚焦到CustomScrollView时，如何停止滚动？

Question

我在CustomScrollView的TextField中苦苦挣扎。

在我的应用程序中，我有一个CustomScrollView内容SliverAppBar和SliverList。 Insise SliverAppBar我放了TextField。当我聚焦TextField时，SliverList自动滚动到顶部位置，然后添加属性showCursor：false，它停止滚动，但是我想显示光标而不滚动。如何将其存档。非常感谢！！

这是我的代码：

import 'package:flutter/material.dart';

class HomeScreen extends StatefulWidget {
  @override
  _HomeScreenState createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      drawer: Drawer(),
      body: SafeArea(
          child: CustomScrollView(
        slivers: <Widget>[
          SliverAppBar(
            leading: Container(),
            floating: true,
            pinned: false,
            snap: true,
            bottom: PreferredSize(
              preferredSize: Size.fromHeight(20.0),
              child: Container(),
            ), // Add this code
            flexibleSpace: Container(
              padding: EdgeInsets.all(10),
              height: 340,
              width: double.infinity,
              child: Stack(
                children: <Widget>[
                  Positioned.fill(
                      child: Container(
                    color: Colors.white,
                  )),
                  Center(
                    child: TextField(
                      autofocus: false,
                      decoration: InputDecoration(
                        border: InputBorder.none,
                        contentPadding: EdgeInsets.only(left: 8.0),
                        hintText: "Search",
                        hintStyle: TextStyle(fontSize: 20),
                      ),
                      showCursor: true, //not show cursor
                    ),
                  ),
                ],
              ),
            ),
          ),
          SliverList(
            delegate: SliverChildBuilderDelegate(
              (BuildContext context, int index) {
                return Container(
                    color: Colors.blue[(index + 1) * 50], height: 150.0);
              },
              childCount: 10,
            ),
          ),
        ],
      )),
    );
  }
}