Question 78924 in Flutter Question posted in
The official Flutter documentation can be found here.

Flutter DropdownButton not showing items

i’m trying to get a list of elements from the cloud firestore and then pass them into DropdownButtonFormField items, the thing is that i’m able to print them in the console but they are not being shown in the DropdownButtonFormField.

Here is my code:

List<String> companies = [];

  Future getCompanies() async {
    await FirebaseFirestore.instance
        .collection('users_web')
        .get()
        .then((value) {
      value.docs.forEach((element) {
        companies.add(element['nom']);
        print(companies.toList());
      });
    });
  }

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

The DropdownButtonFormField:

DropdownButtonFormField<String>(
  decoration: InputDecoration(
    border: InputBorder.none,
  ),
  hint: Text('Sélectionner votre société'),
  items: companies.map(buildMenuItem).toList(),
  onChanged: (value) {
    setState(() {
      company = value!;
    });
  },
  validator: (value) {
    if (!isChecked) {
      if (value == null) {
        return 'Ce champ ne doit pas être vide';
      }
    }
  },
  value: company,
  isExpanded: true,
  iconSize: 26,
  icon: Padding(
    padding: const EdgeInsets.only(right: 8.0),
    child: Icon(
      Icons.arrow_drop_down,
      color: Colors.black,
    ),
  ),
),

I’d be grateful for any help, thanks in advance!

Tags:

2

Answers


  1. 0

    companies is a List of Strings so you can put it as is in the items: field

    BEFORE:
 items: companies.map(buildMenuItem).toList(), 
AFTER:
 items: companies,
    Login or Signup to reply.
  2. 0

    The problem is that your data is fetched async. Your screen is build before the getCompanies is finished. The best way would be to use a FutureBuilder but calling a setState after the data is loaded might be good enough for your case

      Future getCompanies() async {
    await FirebaseFirestore.instance
        .collection('users_web')
        .get()
        .then((value) {
      value.docs.forEach((element) {
        companies.add(element['nom']);
        print(companies.toList());
      });
    });
    setState((){});
  }
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search