我有一个povider类，我正在转换到riverpod 2.0。我已经定义了User类，它是数据模型和下面的NotifierProvider类。在NotifierProvider类中，我有一个函数saveUser（），它根据数据是新的还是从数据库中检索到的来填充变量newUser。notifierProvider类属于User类型。

class Users {
  String? userId;
  String? fName;
  String? lName;
  String? address1;
  String? address2;
  String? city;
  String? state;
  String? zipCode;
  String? cellPhone;
  String? officePhone;
  String? email;
  String? company;
  String? mls;

  Users(
      {this.userId,
      this.fName,
      this.lName,
      this.address1,
      this.address2,
      this.city,
      this.state,
      this.zipCode,
      this.cellPhone,
      this.officePhone,
      this.email,
      this.company,
      this.mls});

  Users copyWith({
    String? userId,
    String? fName,
    String? lName,
    String? address1,
    String? address2,
    String? city,
    String? state,
    String? zipCode,
    String? cellPhone,
    String? officePhone,
    String? email,
    String? company,
    String? mls,
  }) {
    return Users(
      fName: fName ?? this.fName,
      lName: lName ?? this.lName,
      address1: address1 ?? this.address1,
      address2: address2 ?? this.address2,
      city: city ?? this.city,
      state: state ?? this.state,
      zipCode: zipCode ?? this.zipCode,
      cellPhone: cellPhone ?? this.cellPhone,
      officePhone: officePhone ?? this.officePhone,
      email: email ?? this.email,
      company: company ?? this.company,
      mls: mls ?? this.mls,
    );
  }
}

NotifierProvider类的类型为Users，即上面的类。那么，既然我已经将类声明为User类，为什么我在UsersNotifier类中的所有数据元素上都得到“undefined”错误？它们不应该因为通告程序类的类型声明而被声明吗？
如果我将鼠标悬停在扩展通知程序的用户上，一个弹出窗口会显示我正在使用user_provider.dart文件中的“Class Users”，该文件与通知程序类所在的文件相同。

class UsersNotifier extends Notifier<Users> {
  final firestoreService = FirestoreService();
  final companyRef = FirebaseFirestore.instance.collection(('Company'));
  final userRef = FirebaseFirestore.instance.collection(('users'));

// **************************************************

  @override
  Users build() {
    return Users(
      userId: '',
      fName: '',
      lName: '',
      address1: '',
      address2: '',
      city: '',
      state: '',
      zipCode: '',
      cellPhone: '',
      officePhone: '',
      email: '',
      company: '',
      mls: '',
    );
  }

  // functions to update class members
  void updatefName(String newfName) {
    state = state.copyWith(fName: newfName);
  }

  void updatelName(String newlName) {
    state = state.copyWith(lName: newlName);
  }

  void updateaddress1(String newaddress1) {
    state = state.copyWith(address1: newaddress1);
  }

  void updateaddress2(String newaddress2) {
    state = state.copyWith(address2: newaddress2);
  }

  void updateCity(String newCity) {
    state = state.copyWith(city: newCity);
  }

  void updateState(String newState) {
    state = state.copyWith(state: newState);
  }

  void updateZipcode(String newZipcode) {
    state = state.copyWith(zipCode: newZipcode);
  }

  void updateCellPhone(String newCellPhone) {
    state = state.copyWith(cellPhone: newCellPhone);
  }

  void updateOfficePhone(String newOfficePhone) {
    state = state.copyWith(officePhone: newOfficePhone);
  }

  void updateEmail(String newEmail) {
    state = state.copyWith(email: newEmail);
  }

  void updateCompany(String newCompany) {
    state = state.copyWith(company: newCompany);
  }

  void updateMls(String newMls) {
    state = state.copyWith(mls: newMls);
  }

// **************************************************

  saveUser(ref) async {

    if (ref.watch(globalsNotifierProvider).newUser == true) {
      final DocumentSnapshot currentCompanyProfile =
      await companyRef.doc(ref.watch(globalsNotifierProvider).companyId).get();

      var newUser = Users(
          userId: ref.watch(globalsNotifierProvider).currentUserId,
          fName: fName,  <<<  undefined name 'fName'
          lName: lName,  <<<  undefined name 'fLame'
          mls: mls,  <<<  undefined name 'mls'
          mlsId: ref.watch(globalsNotifierProvider).mlsId,
          address1: currentCompanyProfile.get('address1'),
          address2: currentCompanyProfile.get('address2'),
          city: currentCompanyProfile.get('city'),
          state: currentCompanyProfile.get('state'),
          zipcode: currentCompanyProfile.get('zipCode'),
          cellPhone: currentCompanyProfile.get('cellPhone'),
          officePhone: currentCompanyProfile.get('officePhone'),
          companyId: ref.watch(globalsNotifierProvider).companyId;
          company: company),  <<<  undefined name 'company'
      firestoreService.saveUser(newUser, ref);
      ref.read(globalsNotifierProvider.notifier).updatenewUser(false);
    } else {
      final DocumentSnapshot currentuserProfile =
        await userRef.doc(ref.read(globalsNotifierProvider).currentuserId).get();

      var newUser = Users(
          userId: ref.read(globalsNotifierProvider).currentUid,
          fName:
              (fName != null && fName != "") ? fName : currentuserProfile.get('fName'),
          lName:
              (lName != null && lName != "") ? lName : currentuserProfile.get('lName'),
          address1: (address1 != null && address1 != "")
              ? address1
              : currentuserProfile.get('address1'),
          address2: (address2 != null && address2 != "")
              ? address2
              : currentuserProfile.get('address2'),
          city: (city != null && city != "") ? city : currentuserProfile.get('city'),
          state:  (state != null && state != "") ? state : currentuserProfile.get('state'),
          /*state: (globals.selectedState != null)
              ? globals.selectedState
              : globals.currentuserState,*/
          zipcode: (zipCode != null && zipCode != "")
              ? zipCode
              : currentuserProfile.get('zipCode'),
          cellPhone: (cellPhone != null && cellPhone != "")
              ? cellPhone
              : currentuserProfile.get('cellPhone'),
          officePhone: (officePhone != null && officePhone != "")
              ? officePhone
              : currentuserProfile.get('officePhone'),
          companyId: ref.read(globalsNotifierProvider).CompanyId,
          company: (company != null && company != "")
              ? company
              : currentuserProfile.get('Company'),
          mlsId: ref.read(globalsNotifierProvider).mlsId,
          mls: (mls != null && mls != "")
              ? mls
              : currentuserProfile.get('mls'));
      firestoreService.saveUser(newUser, ref);
    }
  }

  deleteUser(String? userId) {
    firestoreService.deleteUser(userId);
  }
}

final usersNotifierProvider = NotifierProvider<UsersNotifier, Users>(() {
  return UsersNotifier();
});

在NotifierProvider类中，我得到了很多未定义的变量，一些命名的参数说它们是未定义的。
在var newUser = User（code中，所有变量都是未定义的。我认为这可能与第一行有关，我从globalsNotifierProvider中分配了一个全局变量：

userId: ref.read(globalsNotifierProvider).currentUid,

“else”语句是我得到大多数错误的地方。每个变量都是未定义的。
我可以得到帮助为什么会发生这种情况？我知道这将是一件简单的事情，但我就是看不出来。
Thanks in advance

1条答案

按热度按时间

pb3skfrl1#

类UsersNotifier没有扩展Users，错误是相当准确的，* 在this * 中没有x。这是因为类不能扩展或实现泛型（T）。
通常ide会给你一个给予警告，告诉你不能做什么，但是当你使用动态和/或空变量时，ide不能确定你是在施魔法还是犯了错误。
这个例子不是一对一的Notifier是做什么，但它有相同的错误，你应该记住，你可能无法访问它，如果它是一个私有变量（_generic）。

class Class {
  String name = 'my_class';
}

class Notifier<T> {
  final T generic;
  Notifier(this.generic);
}

class MyNotifier extends Notifier<Class> {
  MyNotifier() : super(Class());

  void print_name() {
    // print(this.name); // Error
    print(this.generic.name);
  }
}

void main() {
  var instance = MyNotifier();
  instance.print_name();
}

如docs中所述，state是我示例中的generic。如果你想了解更多关于它在做什么或如何做的细节，只需检查类的继承行。
简而言之，使用state.fName等代替fName。

赞(0）回复(0）举报 2023-10-13

dart NotifierProvider类中的函数有许多错误

1条答案

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