How to send Map in request parameters in Flutter?-CodePudding

I ran into a problem, I have a request with parameters in the Map<String, String> apiKeyMap variable, I want to add more parameters that are in the FilterStationParamsModel using the toJson() method, but I get an error when adding one map to another. Tell me how to solve the problem so that parameters are added from the model?

FilterStationParamsModel

class FilterStationParamsModel {
  int? limit;
  int? offset;

  FilterStationParamsModel({
    this.limit,
    this.offset,
  });

  Map<String, String> toJson() {
    return {
      'limit': '123123',
      'offset': '123123',
    };
  }
}

request

  @override
  Future<List<MainModel>> get({
    FilterStationParamsModel? filterStationParamsModel,
  }) async {
    final apiKeyMap = await ApiKey.getCryptoApiKeyMap();
    apiKeyMap!
        .addAll({filterStationParamsModel!.toJson()} as Map<String, String>);
    const String url = '/user';
    final response = await _helper.get(url: url, queryParameters: apiKeyMap);

    final data = jsonDecode(response.body)['data'] as List;
    return data
        .map((json) => MainModel.fromJson(json))
        .toList();
  }

error

CodePudding user response：

filterStationParamsModel!.toJson() is already returning map you can directly use it>

 apiKeyMap!
        .addAll(filterStationParamsModel!.toJson());

If you like to separate key for the model, you can do

 apiKeyMap!.addAll({"apiKeyMap": filterStationParamsModel!.toJson()});