Dart 反序列化的类型未知。需要指定的类型或鉴别器字段

我有以下几个问题

{
    "status": 1,
    "msg": "Success",
    "data": {
        "getFeeCount": [
            {
                "yearId": "1",
                "yearName": "FY 2017-18"
            },
            {
                "yearId": "2",
                "yearName": "FY 2018-19"
            }
        ],
        "getFeeCat": [
            {
                "fee_cat_id": "1",
                "fee_cat_name": "1st Semester Tuition Fee"
            },
            {
                "fee_cat_id": "2",
                "fee_cat_name": "2nd Semester Tuition Fee"
            },
            {
                "fee_cat_id": "3",
                "fee_cat_name": "3rd Semester Tuition Fee"
            },
            {
                "fee_cat_id": "4",
                "fee_cat_name": "4th Semester Tuition Fee"
            },
            {
                "fee_cat_id": "5",
                "fee_cat_name": "5th Semester Tuition Fee"
            },
            {
                "fee_cat_id": "6",
                "fee_cat_name": "6th Semester Tuition Fee"
            },
            {
                "fee_cat_id": "7",
                "fee_cat_name": "7th Semester Tuition Fee"
            },
            {
                "fee_cat_id": "8",
                "fee_cat_name": "8th Semester Tuition Fee"
            },
            {
                "fee_cat_id": "9",
                "fee_cat_name": "Certification Fee Year 1"
            },
            {
                "fee_cat_id": "10",
                "fee_cat_name": "Certification Fee Year 2"
            },
            {
                "fee_cat_id": "11",
                "fee_cat_name": "Certification Fee Year 3"
            },
            {
                "fee_cat_id": "12",
                "fee_cat_name": "Certification Fee Year 4"
            }
        ]
    }
}

我在我的项目中使用构建价值

library dashboard_fiscal_year_model;

import 'package:built_collection/built_collection.dart';
import 'package:built_value/built_value.dart';
import 'package:built_value/serializer.dart';

part 'dashboard_fiscal_year_model.g.dart';

abstract class DashboardFiscalYearModel
    implements
        Built<DashboardFiscalYearModel, DashboardFiscalYearModelBuilder> {
  DashboardFiscalYearModel._();

  factory DashboardFiscalYearModel(
          [updates(DashboardFiscalYearModelBuilder b)]) =
      _$DashboardFiscalYearModel;

  @BuiltValueField(wireName: 'status')
  int get status;
  @BuiltValueField(wireName: 'msg')
  String get msg;
  @BuiltValueField(wireName: 'data')
  DashboardFiscalYearData get data;

  static Serializer<DashboardFiscalYearModel> get serializer =>
      _$dashboardFiscalYearModelSerializer;
}

abstract class DashboardFiscalYearData
    implements Built<DashboardFiscalYearData, DashboardFiscalYearDataBuilder> {
  DashboardFiscalYearData._();

  factory DashboardFiscalYearData([updates(DashboardFiscalYearDataBuilder b)]) =
      _$DashboardFiscalYearData;

  @BuiltValueField(wireName: 'getFeeCount')
  BuiltList<GetFeeCount> get getFeeCount;
  @BuiltValueField(wireName: 'getFeeCat')
  BuiltList<GetFeeCat> get getFeeCat;

  static Serializer<DashboardFiscalYearData> get serializer =>
      _$dashboardFiscalYearDataSerializer;
}

abstract class GetFeeCount implements Built<GetFeeCount, GetFeeCountBuilder> {
  GetFeeCount._();

  factory GetFeeCount([updates(GetFeeCountBuilder b)]) = _$GetFeeCount;

  @nullable
  @BuiltValueField(wireName: 'yearId')
  String get yearId;
  @nullable
  @BuiltValueField(wireName: 'yearName')
  String get yearName;

  static Serializer<GetFeeCount> get serializer => _$getFeeCountSerializer;
}

abstract class GetFeeCat implements Built<GetFeeCat, GetFeeCatBuilder> {
  GetFeeCat._();

  factory GetFeeCat([updates(GetFeeCatBuilder b)]) = _$GetFeeCat;

  @nullable
  @BuiltValueField(wireName: 'fee_cat_id')
  String get feeCatId;
  @nullable
  @BuiltValueField(wireName: 'fee_cat_name')
  String get feeCatName;
}

库仪表板\财务\年度\模型；
导入“package:Build_collection/Build_collection.dart”；
导入“package:build_value/build_value.dart”；
导入“package:builded_value/serializer.dart”；
“仪表板、财政年度、车型g.dart”部分；
抽象类仪表板财务模型
工具
建造{
仪表板财务模型。uz（）；
工厂仪表板财务模型(
[更新（仪表板FiscalyearModelBuilder b）]）=
_$DashboardFiscalYearModel；
@BuiltValueField（wireName:“状态”）
int获取状态；
@BuiltValueField（wireName:'msg'）
字符串获取消息；
@BuiltValueField（wireName:“数据”）
仪表板财务数据获取数据；
静态序列化程序获取序列化程序=>
_$dashboardFiscalYearModelSerializer；
}
抽象类DashboardFiscalYearData
制造工具{
仪表板财务数据。uz（）；
factory仪表板FiscalyearData（[更新（仪表板FiscalyearDataBuilder b）]）=
_$DashboardFiscalYearData；
@BuiltValueField（wireName:'getFeeCount'）
BuiltList获取getFeeCount；
@BuiltValueField（wireName:'getFeeCat'）
BuiltList获取getFeeCat；
静态序列化程序获取序列化程序=>
_$dashboardFiscalYearDataSerializer；
}
抽象类GetFeeCount实现构建{
GetFeeCount.uz（）；
工厂GetFeeCount（[更新（GetFeeCountBuilder b）]）=\u$GetFeeCount；
@可空
@BuiltValueField（wireName:'yearId'）
字符串获取yearId；
@可空
@BuiltValueField（wireName:'DreamName'）
字符串获取名称；
静态序列化程序get Serializer=>\u$getFeeCountSerializer；
}
抽象类GetFeeCat实现已构建{
GetFeeCat.uz（）；
工厂GetFeeCat（[更新（GetFeeCatBuilder b）]）=\u$GetFeeCat；
@可空
@BuiltValueField（wireName:“费用类别id”）
弦得到触感；
@可空
@BuiltValueField（wireName:'费用\类别\名称'）
字符串获取feeCatName；
}

但每当我运行我的应用程序时，我都会出现以下错误

[VERBOSE-2:ui_dart_state.cc(148)] Unhandled Exception: Deserializing '[status, 1, msg, Success, data, {getFeeCount: [{yearId: 1, yearName: FY 2017-...' to 'DashboardFiscalYearModel' failed due to: Deserializing '[getFeeCount, [{yearId: 1, yearName: FY 2017-18}, {yearId: 2, yearName: FY 20...' to 'DashboardFiscalYearData' failed due to: Deserializing '[{fee_cat_id: 1, fee_cat_name: 1st Semester Tuition Fee}, {fee_cat_id: 2, fee...' to 'BuiltList<GetFeeCat>' failed due to: Invalid argument(s): Unknown type on deserialization. Need either specifiedType or discriminator field.
#0      BuiltJsonSerializers._deserialize (package:built_value/src/built_json_serializers.dart:154:11)
#1      BuiltJsonSerializers.deserialize (package:built_value/src/built_json_serializers.dart:105:18)
#2      BuiltJsonSerializers.deserializeWith (package:built_value/src/built_json_serializers.dart:35:12)
#3      DashboardDropDownApiProvider.getFiscalYear (package:dice_admin/resources/dashboard/dashboard_fiscal_year/dashboard_fi<…>
[VERBOSE-2:shell.cc(178)] Dart Error: Unhandled exception:
'dart:isolate/runtime/libtimer_impl.dart': Failed assertion: line 433: '<optimized out>': is not true.
#0      _AssertionError._doThrowNew (dart:core/runtime/liberrors_patch.dart:40:39)
#1      _AssertionError._throwNew (dart:core/runtime/liberrors_patch.dart:36:5)
#2      _Timer._cancelWakeup (dart:isolate/runtime/libtimer_impl.dart:433:12)
#3      _Timer._notifyEventHandler (dart:isolate/runtime/libtimer_impl.dart:299:7)
#4      _Timer._handleMessage (dart:isolate/runtime/libtimer_impl.dart:419:5)
#5      _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:171:12)

[VERBOSE-2:ui_dart_state.cc（148）]未处理的异常：将“[status，1，msg，Success，data，{getFeeCount:[{yearId:1，向往名称：2017财年-…”反序列化为”[getFeeCount，[{yearId:1，向往名称：2017-18财年]失败，{yearId:2，ForearName:FY 20…'到'Dashboard FiscalyearData'失败，原因是：反序列化'[{fee_cat_id:1，fee_cat_name:1st Sember fee}，{fee_cat_id:2，fee…'到'BuiltList'失败，原因是：参数无效：反序列化时类型未知。需要指定类型或鉴别器字段。
#0个BuiltJSonSerializer.\u反序列化（包：build\u value/src/build\u json\u serializers.dart:154:11）
#1 BuiltJsonSerializers.deserialize（包：build_value/src/build_json_serializers.dart:105:18）
#2 BuiltJsonSerializers.deserializeWith（包：build_value/src/build_json_serializers.dart:35:12）
#3 dashboard DropDownApiprovider.getFiscaleEAR（包：dice_admin/resources/dashboard/dashboard_fiscal_year/dashboard_fi
[VERBOSE-2:shell.cc（178）]Dart错误：未处理的异常：
“dart:isolate/runtime/libtimer_impl.dart”：失败的断言：第433行：“”：不正确。
#0断言错误。doThrowNew（dart:core/runtime/liberror\u patch.dart:40:39）
#1 AssertionError.throwNew（dart:core/runtime/liberrors_patch.dart:36:5）
#2计时器。取消唤醒（dart:isolate/runtime/libtimer\u IMPLL.dart:433:12）
#3 \u Timer.\u notifyEventHandler（dart:isolate/runtime/libtimer\u impl.dart:299:7）
#4 _Timer._handleMessage（dart:isolate/runtime/libtimer_impl.dart:419:5）
#5 _RawReceivePortImpl._handleMessage（dart:isolation/runtime/libisolation_patch.dart:171:12）

我已经多次重新生成代码，我认为序列化程序也映射正确

我浏览了这篇文章

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它使用了一个自定义插件，生成值解决了这个问题，还是我需要使用自定义生成值？我忘了为GetFeeCat类添加

Serailizer