如何在序列化中将类型信息添加到JSON？ [英] How to add types information to JSON on serialization?

问题描述

在许多地方，Angular需要 Date 对象，而JSON包含日期的字符串表示。

Angular requires Date objects in many places whereas JSON contains string representation of the date.

我想添加一个包含日期值的属性数组：

I want to add an array of properties which contain date values:

class Foo
{
    public int IntProp {get;set;}
    public DateTime? Prop1 {get;set;}
    public DateTime  Prop2 {get;set;}
    public Bar Bar {set;set;}
}

class Bar
{
    public DateTime Prop {get;set;}
    public IEnumerable<DateTime?> Dates {get;set;} 
}

然后Foo应该如下序列化： / p>

Foo should then be serialized like this:

{
   "IntProp": 1,
   "Prop1": "...",
   "Prop2": "...",
   "Bar": {
       "Prop": "..."
   },

   "<Dates>": [ "Prop1", "Prop2", "Bar.Prop", "Bar.Dates"]
}

这允许我自动将字符串转换为客户端的日期对象，而不测试每个属性是否可转换为 Date 在此问题中描述。

This allows me to automatically convert strings to date objects at the client side without testing every property whether it is convertible to Date like it is described in this question.

我可以收集路径日期属性，但不知道如何添加填充数组到根。

I can collect the paths of date properties, but have no idea how to add populated array to the root.

推荐答案

您可以转换为中间体 JObject 并添加属性那里。例如，给定以下转换器：

You could convert to an intermediate JObject and add the property there. For instance, given the following converter:

public class PathLoggingDateTimeConverter : IsoDateTimeConverter
{
    public const string DatePathPropertyName = "<Dates>";

    readonly List<string> paths = new List<string>();

    public override bool CanConvert(Type objectType)
    {
        if (!base.CanConvert(objectType))
            return false;
        // Not for DateTimeOffset
        return objectType == typeof(DateTime) || objectType == typeof(DateTime?);
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        base.WriteJson(writer, value, serializer);
        if (value != null)
            paths.Add(writer.Path);
    }

    public IList<string> Paths { get { return paths; } }
}

$ b

        var root = new Foo
        {
            IntProp = 101,
            Prop1 = DateTime.Today.ToUniversalTime(),
            Prop2 = DateTime.Today.ToUniversalTime(),
            Bar = new Bar
            {
                Prop = DateTime.Today.ToUniversalTime(),
                Dates = new List<DateTime?> { null, DateTime.Today.ToUniversalTime() },
            },
        };

        var converter = new PathLoggingDateTimeConverter();
        var settings = new JsonSerializerSettings { Converters = new[] { converter } };
        var obj = JObject.FromObject(root, JsonSerializer.CreateDefault(settings));
        obj[PathLoggingDateTimeConverter.DatePathPropertyName] = JToken.FromObject(converter.Paths);

        Console.WriteLine(obj);

结果是：

{
  "IntProp": 101,
  "Prop1": "2016-10-25T04:00:00Z",
  "Prop2": "2016-10-25T04:00:00Z",
  "Bar": {
    "Prop": "2016-10-25T04:00:00Z",
    "Dates": [
      null,
      "2016-10-25T04:00:00Z"
    ]
  },
  "<Dates>": [
    "Prop1",
    "Prop2",
    "Bar.Prop",
    "Bar.Dates[1]"
  ]
}

这篇关于如何在序列化中将类型信息添加到JSON？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！