嵌套对象的JSON序列化飞镖

Question

我正在尝试使用JSON_Serializable库为我的嵌套对象生成FromJSON和TOJSON功能。但是，当我尝试使用生成的函数时，我遇到了一个错误的嵌套对象。

我想我了解如何写托伊森和源头功能。但是我想弄清楚如何与JSON_Serializable库一起使用并使用生成的代码。

与模型的类：

import 'package:json_annotation/json_annotation.dart';
part 'models.g.dart';

@JsonSerializable()
class OfficesList {
  List<Office> offices;
  OfficesList({required this.offices});

  factory OfficesList.fromJson(Map<String, dynamic> json) => _$OfficesListFromJson(json);

  Map<String, dynamic> toJson() => _$OfficesListToJson(this);
}

@JsonSerializable()
class Office {
  final String name;
  final String address;
  final String image;

  Office({required this.name, required this.address, required this.image});

  factory Office.fromJson(Map<String, dynamic> json) => _$OfficeFromJson(json);

  Map<String, dynamic> toJson() => _$OfficeToJson(this);
}

生成类：

// GENERATED CODE - DO NOT MODIFY BY HAND

part of 'models.dart';

// **************************************************************************
// JsonSerializableGenerator
// **************************************************************************

OfficesList _$OfficesListFromJson(Map<String, dynamic> json) => OfficesList(
      offices: (json['offices'] as List<dynamic>)
          .map((e) => Office.fromJson(e as Map<String, dynamic>))
          .toList(),
    );

Map<String, dynamic> _$OfficesListToJson(OfficesList instance) =>
    <String, dynamic>{
      'offices': instance.offices,
    };

Office _$OfficeFromJson(Map<String, dynamic> json) => Office(
      name: json['name'] as String,
      address: json['address'] as String,
      image: json['image'] as String,
    );

Map<String, dynamic> _$OfficeToJson(Office instance) => <String, dynamic>{
      'name': instance.name,
      'address': instance.address,
      'image': instance.image,
    };

void main(){
  Office of1 = Office(name: "pupa", address: "lupa", image: "image");
  Office of2 = Office(name: "lupa", address: "pupa", image: "image");

  OfficesList list1 = OfficesList(offices: [of1,of2]);
  
  OfficesList list2 = OfficesList.fromJson(list1.toJson());

  print(list2.toJson());
}

这些行中的例外

OfficesList list2 = OfficesList.fromJson(list1.toJson())

.map((e) => Office.fromJson(e as Map<String, dynamic>))

Unhandled exception:
type 'Office' is not a subtype of type 'Map<String, dynamic>' in type cast
#0      _$OfficesListFromJson.<anonymous closure> (package:jsom_test/models.g.dart:11:41)
#1      MappedListIterable.elementAt (dart:_internal/iterable.dart:413:31)
#2      ListIterator.moveNext (dart:_internal/iterable.dart:342:26)
#3      new _GrowableList._ofEfficientLengthIterable (dart:core-patch/growable_array.dart:189:27)
#4      new _GrowableList.of (dart:core-patch/growable_array.dart:150:28)
#5      new List.of (dart:core-patch/array_patch.dart:51:28)
#6      ListIterable.toList (dart:_internal/iterable.dart:213:44)
#7      _$OfficesListFromJson (package:jsom_test/models.g.dart:12:12)
#8      new OfficesList.fromJson (package:jsom_test/models.dart:9:62)
#9      main (package:jsom_test/json_test.dart:9:35)
#10     _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:297:19)
#11     _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:192:12)