颤振：类型“\u InternalLinkedHashMap”不是类型“String”的子类型

Question

我正在尝试使用Dio客户端进行API调用。当我收到响应时，它会抛出一个错误

“\u InternalLinkedHashMap”不是“String”类型的子类型

试图解决它，但我不能。下面是代码

  Future<dynamic> get(
      String uri, {
        Map<String, dynamic> queryParameters,
        Options options,
        CancelToken cancelToken,
        ProgressCallback onReceiveProgress,
      }) async {
    try {
      final Response response = await _dio.get(
        uri,
        queryParameters: queryParameters,
        options: options,
        cancelToken: cancelToken,
        onReceiveProgress: onReceiveProgress,
      );
      return response.data;
    } catch (e) {
      print(e.toString());
      throw e;
    }
  }
} 

后Api调用

Future<News> getPosts() async {
    try {
      final res = await _dioClient.get(Endpoints.getPosts);
      return News.fromJson(res);
    } catch (e) {
      print(e.toString());
      throw e;
    }
  }

模型类使用内置值

abstract class News implements Built<News, NewsBuilder> {
  News._();

  factory News([updates(NewsBuilder b)]) = _$News;

  @BuiltValueField(wireName: 'status')
  String get status;
  @BuiltValueField(wireName: 'totalResults')
  int get totalResults;
  @BuiltValueField(wireName: 'articles')
  BuiltList<Articles> get articles;
  String toJson() {
    return json.encode(serializers.serializeWith(News.serializer, this));
  }

  static News fromJson(String jsonString) {

    return serializers.deserializeWith(
        News.serializer, json.decode(jsonString));
  }

  static Serializer<News> get serializer => _$newsSerializer;
}

序列化程序类

@SerializersFor([
  News,
  Articles,
  Source,
])
final Serializers serializers = (_$serializers.toBuilder()..addPlugin(StandardJsonPlugin())).build();

帮我怎么解决

Answer 1

你需要改变两件事

1） 在内置值中使用JSONSerializer而不是默认序列化器。

2）使用响应。toString（）而不是dio中的数据。这里是我的一个工作示例，只需复制您需要的部分。

内建价值模型

abstract class TravelRequest implements Built<TravelRequest, TravelRequestBuilder> {
  TravelRequest._();

  factory TravelRequest([updates(TravelRequestBuilder b)]) = _$TravelRequest;

  @nullable
  @BuiltValueField(wireName: 'id')
  int get id;

  @nullable
  @BuiltValueField(wireName: 'country_from')
  String get countryFrom;

  @nullable
  @BuiltValueField(wireName: 'traveler_name')
  String get travelerName;

  @nullable
  @BuiltValueField(wireName: 'traveler_email')
  String get travelerEmail;

  @nullable
  @BuiltValueField(wireName: 'description')
  String get description;

  String toJson() {
    return json.encode(jsonSerializers.serializeWith(TravelRequest.serializer, this));
  }

  static TravelRequest fromJson(String jsonString) {
    return jsonSerializers.deserializeWith(TravelRequest.serializer, json.decode(jsonString));
  }

  static Serializer<TravelRequest> get serializer => _$travelRequestSerializer;
}

如何与Dio一起使用

  Future createTravelRequest(TravelRequest travelRequest) {
return _apiProvider.dio.post(rootPath, data: travelRequest.toJson()).then((response) {
  travelRequests.add(TravelRequest.fromJson(response.toString()));
});
  }