flutter dart JsonSerializable 继承 class

Question

我有以下两个类，其中一个是从另一个扩展而来的，如下所示：

@JsonSerializable(nullable: true)
class Response {
  final String responseCode;
  final String responseMessage;
  final String errorLog;
  Response({this.errorLog, this.responseCode, this.responseMessage});
  factory Response.fromJson(Map<String, dynamic> json) =>
      _$ResponseFromJson(json);
}

..................................................... …………

 @JsonSerializable(nullable: false)
class Verify extends Response {
  Data data;
  Verify({
    this.data,
  });
  factory Verify.fromJson(Map<String, dynamic> json) => _$VerifyFromJson(json);
  Map<String, dynamic> toJson() => _$VerifyToJson(this);
}

并且每当我尝试从验证 clasit 中读取响应class 属性时总是 null

那么请如何实现这一目标？

Answer 1

我已经通过将参数传递给 super 来验证 class 构造函数来解决这个问题

@JsonSerializable()
class VerifyResponse extends Response {
  Data data;

  VerifyResponse({
    this.data,
    String responseCode,
    String responseMessage,
  }) : super(responseCode: responseCode, responseMessage: responseMessage);

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

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

对于响应 class 它保持不变

@JsonSerializable()
class Response {
  final String responseCode;
  final String responseMessage;

  Response({this.responseCode, this.responseMessage});

  factory Response.fromJson(Map<String, dynamic> json) =>
      _$ResponseFromJson(json);
}

这有点烦人，但就是这样。

Answer 2

您应该从响应 Class 中删除“最终”关键字

@JsonSerializable(nullable: true)
    class Response {
      String responseCode;
      String responseMessage;
      String errorLog;
      Response({this.errorLog, this.responseCode, this.responseMessage});
      factory Response.fromJson(Map<String, dynamic> json) =>
           _$ResponseFromJson(json);
}

Answer 3

它通过添加super(); 显式地传递给子类的构造函数。

@JsonSerializable()
class VerifyResponse extends Response {
  Data data;

  VerifyResponse({
    this.data,
    String responseCode,
    String responseMessage,
    //No need to list all parent class properties
    }) : super();

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

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