如何使用json.NET反序列化动态命名的根节点

Question

这是json文件的一个示例:

{
   "John Smith": {
      "id": "72389",
      "email": "johnsmith@gmail.com",
      "books": [
         {
            "id": "0",
            "title": "The Hunger Games",
            "rating": "5"
         },
         {
            "id": "1",
            "title": "Harry Potter and the Order of the Phoenix",
            "rating": "3"
         },
      ],
      "magazines": [
         {
            "id": "2",
            "title": "National Geographic",
            "rating": "1"
         },
         {
            "id": "3",
            "title": "Wired",
            "rating": "4"
         }
      ],
   }
}

请注意,根节点有一个动态名称(John Smith),我需要反序列化的每个json都有不同的名称.这个json结构需要按如下方式设置类:

public class RootObject
{
    public JohnSmith { get; set; }
}

public class JohnSmith //oops
{
    public string id { get; set; }
    public string email { get; set; }
    public List<Book> books { get; set; }
    public List<Magazine> magazines { get; set; }
}

public class Book
{
    public string id { get; set; }
    public string title { get; set; }
    public string rating { get; set; }
}

public class Magazine
{
    public string id { get; set; }
    public string title { get; set; }
    public string rating { get; set; }
}

我的目标是反序列化"绕过/忽略"根对象,最重要的是动态命名节点.这并不重要,但我希望能够获取姓氏并将其设置为Person类的属性.

public class Person
{
    public string id { get; set; }
    public string email { get; set; }
    public string name { get; set; }
    public List<Book> books { get; set; }
    public List<Magazine> magazines { get; set; }
}

public class Book
{
    public string id { get; set; }
    public string title { get; set; }
    public string rating { get; set; }
}

public class Magazine
{
    public string id { get; set; }
    public string title { get; set; }
    public string rating { get; set; }
}

这是我现在这样做的方式:

var jo = JObject.Parse(json);
var deserializable = jo.First.First.ToString();

string name;
var jp = (JProperty)jo.First;
if (jp != null) name = jp.Name;

var person = JsonConvert.DeserializeObject<Person>(deserializable);
person.name = name;

这工作正常,但我想知道,也许通过使用自定义JsonConverter可以做得更好？我担心这有点过头了,所以我在这里要求一些帮助......

无论如何,如果有更好的方法来实现这一目标,请分享.

Answer 1

我会保留你的解决方案的第一部分(反序列化JObject),但我不会做另一个序列化.我的代码看起来像这样:

var jo = JObject.Parse(json);
var jp = jo.Properties().First();
var name = jp.Name;
var person = jp.Value.ToObject<Person>();

编辑:

如果您需要自定义转换器,可以使用以下代码.转换器将您的对象转换为Persons 列表,其中每个属性代表另一个属性Person.

class PersonListConverter : JsonConverter
{
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        var list = (PersonList) value;

        writer.WriteStartObject();

        foreach (var p in list.Persons)
        {
            writer.WritePropertyName(p.Name);
            serializer.Serialize(writer, p);
        }

        writer.WriteEndObject();
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        var jo = serializer.Deserialize<JObject>(reader);
        var result = new PersonList();
        result.Persons = new List<Person>();

        foreach (var prop in jo.Properties())
        {
            var p = prop.Value.ToObject<Person>();
            // set name from property name
            p.Name = prop.Name;
            result.Persons.Add(p);
        }

        return result;
    }

    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(PersonList);
    }
}

哪里PersonList是这样的:

[JsonConverter(typeof(PersonListConverter))]
class PersonList
{
    public List<Person> Persons { get; set; }
}