Flutter Firebase - Checkbox is not enabled in SliverList

[flutter testing]

I'm reading fields carName, sportsCheckbox, familyCheckboxfrom firebase collection 'testcrud', and displaying in Listview. 

1) The output in the ListView looks like (Left Arrow, carName, SportCarCheckBox [], FamilyCarCheckbox[]>, Right Arrow)

The code should allow me to check or uncheck any checkbox but These are the issues I'm facing:

a) Either checkboxes are disabled

b) or all the checkBoxes in all the rows and columns are checked or unchecked 

 

Any help will be appreciable.

----------------------------

    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

[Muhd Fauzi]

I want this what app-release.apk i do not download