import 'package:json_annotation/json_annotation.dart'; part 'pic_message.g.dart'; @JsonSerializable() class PicData { @JsonKey(name: "tr_id") late int trId; late int num; late int time; late String data; PicData(); factory PicData.fromJson(Map json) => _$PicDataFromJson(json); Map toJson() => _$PicDataToJson(this); }