c# - 如何强制不存在的属性为空？

Question

如果我有如下架构：

{
  "id": "http://example.com/my_application",
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "my_application_schema",
  "additionalProperties": false,
  "definitions": {
    "NumberField": {
      "type": "number",
      "min": 0,
      "max": 2147483647
    },
    "StringField": {
      "type": "string",
      "minLength": 1,
      "maxLength": 12
    },
    "MainObject": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "object1": {
          "$ref": "#/definitions/Object1"
        },
        "object2": {
          "$ref": "#/definitions/Object2"
        }
      },
      "minProperties": 1,
      "maxProperties": 1
    },
    "Object1": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "field1": {
          "$ref": "#/definitions/NumberField",
          "proto_field": 1
        }
      },
      "required": [
        "field1"
      ]
    },
    "Object2": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "field1": {
          "$ref": "#/definitions/StringField",
          "proto_field": 1
        }
      },
      "required": [
        "field1"
      ]
    }
  },
  "type": "object",
  "properties": {
    "Content": {
      "$ref": "#/definitions/MainObject"
    }
  }
}

我正在使用以下代码生成一组 C# 类：

NJsonSchema.JsonSchema4 schema = await NJsonSchema.JsonSchema4.FromFileAsync(<path to schema>);
var generator = new CSharpGenerator(schema);
var file = generator.GenerateFile();

并且，使用生成的类，执行以下操作：

My_application_schema o = JsonConvert.DeserializeObject<My_application_schema>(@"
            {
'Content': {
'object1': {
'field1': 20
}
}
}");

然后反序列化完成而没有错误，但生成的对象o包含对object1和object2的引用，尽管object2的所有成员都是空的。

JsonSerializerSettings settings = new JsonSerializerSettings()
{
    NullValueHandling = NullValueHandling.Ignore
};
String s = Newtonsoft.Json.JsonConvert.SerializeObject(o, settings);
// {"Content":{"object1":{"field1":20.0},"object2":{}}}

我需要的是object2要么不存在于反序列化对象中，要么设置为 null。有没有办法做到这一点，无论是在模式本身还是在这个管道中涉及的各种进程之一？

score 3 · Accepted Answer

这是否意味着您的 object2 为空或您正在寻找的类型，因此所需的架构更改将类似于：

"properties": {
  "object1":  {
    "oneOf": [
      {
        "$ref": "#/definitions/Object1"
      },
      {
        "type": "null"
      }
    ]
  },
  "object2": {
    "oneOf": [
      {
        "$ref": "#/definitions/Object2"
      },
      {
        "type": "null"
      }
    ]
  }
}

可以在显示公司对象的github 页面上找到类似的示例