How to fix rangeerror in flutter-CodePudding

I'm using a package call alphabet_list_scroll_view 2.0.0 in my flutter project.

I'm using the example code from their documentation but I'm getting

RangeError (index): Invalid value: Valid value range is empty: 0

for some reason. I'm trying to add itemCount right above itemBuilder but I'm getting the parameter is not existed.

Any help would be really appreciated with dummy/mock list..

Here is part of the code from the example code that they provided.

class _AboutScreenState extends State<AboutScreen> {
  List<User> userList = [];
  List<String> strList = ['Ja', 'bo', 'Ce', 'Do', 'Ha', 'Tu', 'Zu'];
  List<Widget> favouriteList = [];
  List<Widget> normalList = [];
  TextEditingController searchController = TextEditingController();

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        home: Scaffold(
      appBar: AppBar(
        title: const Text('Plugin example app'),
      ),
      body: AlphabetListScrollView(
        strList: strList,
        highlightTextStyle: TextStyle(
          color: Colors.yellow,
        ),
        showPreview: true,
        itemBuilder: (context, index) {
          return normalList[index];
        },
        indexedHeight: (i) {
          return 80;
        },
        keyboardUsage: true,
      ),
    ));
  }
}

CodePudding user response：

You are populating the normalList but using on itemBuilder. You can do it on initState to solve this error.

  @override
  void initState() {
    super.initState();
    for (final item in strList) {
      normalList.add(Text(item));
    }
  }

And itemcount isnt a valid key in alphabet list scroll view