从Firebase获取数据的Sliverlist内部的复选框不起作用

Question

我正在阅读carName，carCheckbox表单firebase集合，并显示在Listview中。列表视图中未启用复选框。

1）我在ListView中的输出看起来像 <-，carName，SportCarCheckBox []，FamilyCarCheckbox []，-> 2）这些是我面临的问题： a）任一复选框均被禁用 b）或选中所有行和列中的所有checkBox或取消选中

   import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
final formKey = new GlobalKey<FormState>();
String carName = '';
void main() => runApp(MyApp());
//====================================
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {return MaterialApp(home: TestListPage(),);}}
//====================================
class TestListPage extends StatefulWidget {
  @override
  _TestListPageState createState() => _TestListPageState();}
//====================================
class _TestListPageState extends State<TestListPage> {
  Stream<int> stream;
  @override
  Widget build(BuildContext context) {
    return Scaffold(appBar: AppBar(title: Text('Title Checkbox'),),
      body: TestListCustomScrollViewWidget(),);}
//====================================
  Widget TestListCustomScrollViewWidget() {
    print ('.............................................');
    return CustomScrollView(scrollDirection: Axis.vertical, slivers: <Widget>[
      SliverAppBar(title: Text('Sliverlist')),
      Form(key: formKey, child: TestListStreamBuilderListWidget(),)]);}

  //================================
  Widget TestListStreamBuilderListWidget() {
    return    StreamBuilder(stream: Firestore.instance.collection('testcrud').orderBy('carName').snapshots(),
        builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
             if(snapshot.hasData) {return SliverList(
              delegate: SliverChildBuilderDelegate(
                    (context, index) => Container(child: TestListTileWidget(snapshot, index),),
                childCount: snapshot.hasData ? snapshot.data.documents.length : 0,),);}});}

//====================================
  Widget TestListTileWidget(snapshot, index){
//    print('carName:' + snapshot.data.documents[index]['carName']);
    return ListTile(
      enabled: true, leading: Icon(Icons.arrow_back_ios), trailing: Icon(Icons.arrow_forward_ios,),
      title: new Row(
        children: <Widget>[
          new Expanded(child: new Text(snapshot.data.documents[index]['carName'])),
          _checkBox('Sports', snapshot.data.documents[index]['sportsCheckbox']),
          _checkBox('Family', snapshot.data.documents[index]['familyCheckbox']),],),);}
//=======================================
  Widget _checkBox(String category, bool isChecked) {
    return Column(
      children: <Widget>[
        Text('$category',),
        Checkbox(value: isChecked,
          onChanged: (bool value) {setState(() {isChecked = value;});
            print('updated $category value to: $value');},)],);}
//====================================
} // End of Class

该代码应允许我选中或取消选中任何复选框。任何帮助都将是可贵的。