从Firebase获取数据以插入到MultiSelectFormField（widgets）

Question

我想从Firebase数据库检索数据以将其插入到我的MultiSelectFormField类型表单中时遇到问题。当我单击表单时，列表不会打开。错误如下：

[[ERROR：flutter / lib / ui / ui_dart_state.cc（157）]未处理的异常：类型'String'不是'index'E / flutter类型'int'的子类型（27777）：＃0新的MultiSelectFormField ...（包：multiselect_formfield / multiselect_formfield.dart：73：55）E / flutter（27777）：在每个列表中排名第一（dart：core-patch / growable_array.dart：285：8）E / flutter（27777）：＃2新的MultiSelectFormField ..（package：multiselect_formfield / multiselect_formfield.dart：72：28）

我创建此表单的方法

 Widget buildMultiForm(BuildContext context,EndRegisterViewModel e) {
    return MultiSelectFormField(


        autovalidate: e.autoValidateTag,
        titleText: 'Choisissez les dispositifs qui vous intéressent',
        validator: (value)
        {
          if (e.selectedsValueTag == null || e.selectedsValueTag.length == 0) {
            return 'Veuillez sélectionner au moins un tag';
          }
          return null;
        },
        dataSource: [
            e.allTags.map((data){
              return {'display': '#$data', 'value': data};
            }).toList(),
        ],
        textField: 'display',
        valueField: 'value',
        okButtonLabel: 'OK',
        cancelButtonLabel: 'Annuler',
        hintText: 'Choisissez-en un ou plus',
        value: e.selectedsValueTag,
        onSaved: (value) {
          e.autoValidateTag=true;
          e.selectedsValueTag = value;

        },
      );

  }



/////////////////////////////////////////////
/////User Model ////////////////////////////
////////////////////////////////////////////
class User {
  String uid;
  String name;
  String surname;
  String email;
  String city;
  String country;
  int experience;
  String numberTel;
  String department;
 /// List<String> tags;
  String tags;
  String reason;
  List pictures;
  bool isRegistered;
  List confirmedMatches;
  List receivedMatches;
  List sendMatches;

  ///USER FROM DATA////
  /// /// /// //// ///

  User.fromData(Map<String, dynamic> data)
      : uid = data['uid'],
        email = data['email'],
        name = data['name'],
        surname = data['surname'],
        city = data['city'],
        country = data['country'],
        experience = data['experience'],
        numberTel = data['numberTel'],
        department = data['department'],
        tags = data['tags'],
        reason = data['reason'],
        pictures = data['pictures'] as List,
        isRegistered = data['isRegistered'] as bool ?? false,
        confirmedMatches = data['confirmedMatches'] as List,
        receivedMatches = data['receivedMatches'] as List,
        sendMatches = data['sendMatches'] as List;

  Map<String, dynamic> toJson() {
    return {
      'uid': uid,
      'email': email,
      'name': name,
      'surname': surname,
      'city': city,
      'country': country,
      'experience': experience,
      'numberTel': numberTel,
      'department': department,
      'tags': tags,
      'pictures': pictures,
      'isRegistered': isRegistered,
      'reason':reason,
      'confirmedMatches': confirmedMatches,
      'receivedMatches': receivedMatches,
      'sendMatches': sendMatches,
    };
  }

////ViewModel//////
//////////////////
////////////////



class EndRegisterViewModel extends BaseModel {
  final FirestoreService _firestoreService = locator<FirestoreService>();
  final NavigationService _navigationService = locator<NavigationService>();
  final AuthService _auth = locator<AuthService>();
  final formKey = new GlobalKey<FormState>();

  List<String> _allDepartments;
  List<String> _allTags;

  List<String> get allDepartments => _allDepartments;
  List<String> get allTags => _allTags;


  List _pictures;

  String _name;
  String _surname;
  String _reason;
  String _numberTel;
  String _errorMessage;
  List _selectedsValueTag;
  bool _autoValidateTag = false;


  bool get autoValidateTag => _autoValidateTag;

  set autoValidateTag(bool newValue) {
    if (autoValidateTag != newValue) {
      _autoValidateTag = newValue;
      notifyListeners();
    }
  }

  List get selectedsValueTag => _selectedsValueTag;



  set selectedsValueTag(List newValue) {
    if (selectedsValueTag != newValue) {
      _selectedsValueTag = newValue;
      notifyListeners();
    }
  }
  String _selectedValueDepartment;
  String get selectedValueDepartment => _selectedValueDepartment;

  set selectedValueDepartment(String newValue) {
    if (selectedValueDepartment != newValue) {
      _selectedValueDepartment = newValue;
      notifyListeners();
    }
  }

  /// CONSTRUCTOR  ///
  /// /// /// /// ////

  EndRegisterViewModel() {
    _allDepartments = new List<String>();
    _allTags = new List<String>();
  }

  set pictures(List value) {
    _pictures = value;
  }

  set name(String value) {
    _name = value;
  }

  set surname(String value) {
    _surname = value;
  }

  set reason(String value) {
    _reason = value;
  }

  set numberTel(String value) {
    _numberTel = value;
  }

  String get errorMessage => _errorMessage;
  String get reason => _reason;

  bool validateAndSave() {
    final form = formKey.currentState;
    if (form.validate()) {
      form.save();
      return true;
    }
    return false;
  }

  void setErrorMessage(String errorMessage) {
    _errorMessage = errorMessage;
    notifyListeners();
  }

  Future updateUser() async {
    setBusy(true);
    if (validateAndSave()) {
      User _user = _auth.currentUser;

      _user.name = _name;
      _user.surname = _surname;
      _user.department = _selectedValueDepartment;
      _user.tags = _selectedsValueTag.toString();
      _user.reason = _reason;
      _user.numberTel = _numberTel;
      _user.isRegistered = true;

      var result = await _firestoreService.createOrUpdateUser(_user);

      if (result == null) {
        _auth.currentUser = _user;
        _navigationService.navigateTo("/communities");
      } else {
        setErrorMessage(result);
        setBusy(false);
      }
    } else {
      setBusy(false);
    }
  }

  Future<void> initialize() async {
    setBusy(true);

    if (_allDepartments == null || _allDepartments.isEmpty) {
      _allDepartments = await _firestoreService.getAllDepartments(); /// it's work
      notifyListeners();
    }

    if (_allTags == null || _allTags.isEmpty) {
      _allTags = await _firestoreService.getAllTags(); 
      notifyListeners();
    }

    setBusy(false);
  }
}

Answer 1

datasource = e.allTags.map((data){
          return {'display': '#$data', 'value': data};
        }).toList(),

应该工作。

作为数据源保存类型为List（documentation）的数据。

您的代码：

e.allTags.map((data){
          return {'display': '#$data', 'value': data};
        }).toList(),

本身创建一个List，其中包含allTags >>]的每个元素