The named parameter 'builder' is required, but there's no corresponding argument and utils

Question

I'm trying to add one alert box for language selection, but couldn't figure out the builder error I'm facing. it was working fine with flutter older version but not with 2.2.3 version of flutter Thanks

for the help Looking forward for the solution

The named parameter 'builder' is required, but there's no corresponding argument. The named parameter 'child' isn't defined. Undefined name 'Utils'.

   Future <void> _languageCheck() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();

    final firstRun = prefs.getBool("firstRunLanguage");
    (firstRun ?? false)
        ? () {}
        : await showDialog(
        barrierDismissible: false,
        context: context,
        child: AlertDialog(content: LanguageDialog()));
    await prefs.setBool('firstRunLanguage', true);
  }

Widget

class LanguageDialog extends StatefulWidget {
  @override
  _LanguageDialogState createState() => _LanguageDialogState();
}

class _LanguageDialogState extends State<LanguageDialog> {
  var langCode = "en";

  void getLanguage() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    langCode = prefs.getString("language") ?? kAdvanceConfig['DefaultLanguage'];
    printLog("langCode-->$langCode");
    setState(() {});
  }

  @override
  void initState() {
    super.initState();
    getLanguage();
  }

  @override
  Widget build(BuildContext context) {
    List<Widget> list = [];
    List<Map<String, dynamic>> languages = Utils.getLanguagesList(context);
    for (var i = 0; i < languages.length; i++) {
      // if (langCode == languages[i]["code"]) {
      //   print(languages[i]["code"]);
      // }
      list.add(
        ListTile(
          leading: Image.asset(
            languages[i]["icon"],
            width: 30,
            height: 20,
            fit: BoxFit.cover,
          ),
          title: Text(languages[i]["name"]),
          trailing: langCode == languages[i]["code"]
              ? const Icon(
            Icons.radio_button_checked,
            color: Colors.teal,
          )
              : const Icon(
            Icons.radio_button_off,
            color: Colors.teal,
          ),
          onTap: () async {
            setState(() {
              langCode = languages[i]["code"];
            });
            await Provider.of<AppModel>(context, listen: false)
                .changeLanguage(languages[i]["code"], context);
          },
        ),
      );
      if (i < languages.length - 1) {
        list.add(
          Divider(
            color: Theme.of(context).primaryColorLight,
            height: 1.0,
            indent: 75,
            //endIndent: 20,
          ),
        );
      }
    }
    return SingleChildScrollView(
      child: Column(
        children: [
          ...list,
          const LinearProgressIndicator(),
          FlatButton(
              onPressed: () {
                Navigator.pop(context);
              },
              child: const Text("OK")),
        ],
      ),
    );
  }
}

score 1 · Answer 1 · answered Sep 23 '21 at 10:08

1

showDialog doesn't have child, use its builder like

     await showDialog(
            barrierDismissible: false,
            context: context,
            builder: (context) => // here 
             AlertDialog(content: LanguageDialog()))

More on showDialog

answered Sep 23 '21 at 10:08

Md. Yeasin Sheikh

54,221
7
29
56

thank you and one more what's wrong with Utils.getLanguagesList – Rushika Pawar Sep 23 '21 at 10:13
I think that's a class, or using others packages, can you include what is `Utils` in your case? – Md. Yeasin Sheikh Sep 23 '21 at 10:15
List>? languages = getLanguages(); sorted out this was the main culprit – Rushika Pawar Sep 23 '21 at 10:32
Is it coming from a separate class? `getLanguages();` can you include the class and how `getLanguages()` is named on `Utils` class on question. – Md. Yeasin Sheikh Sep 23 '21 at 10:35
yes it separate class coming from some other file – Rushika Pawar Sep 23 '21 at 11:14
Can you include how you are importing that file, also that method. – Md. Yeasin Sheikh Sep 23 '21 at 11:15

score 1 · Answer 2 · answered Sep 23 '21 at 10:26

You used showDialog() method which has a required parameter caller builder so you must provide the builder argument so try like below


Future <void> _languageCheck(BuildContext context) async {
    SharedPreferences prefs = await SharedPreferences.getInstance();

    final firstRun = prefs.getBool("firstRunLanguage");
    (firstRun ?? false)
        ? () {}
        : await showDialog(
        barrierDismissible: false,
        context: context,
        /// this builder parameter is required
        builder:(context) => AlertDialog(content: LanguageDialog()));
    await prefs.setBool('firstRunLanguage', true);
  }

The named parameter 'builder' is required, but there's no corresponding argument and utils

2 Answers2