如何实现将 serialize/deserialize 复杂类型转换为简单类型的 Newtonsoft JSON 转换器

How to implement a Newtonsoft JSON converter that will serialize/deserialize a complex type into a simple type

我希望实现 https://github.com/HeadspringLabs/Enumeration。目前,当我尝试 serialize/deserialize 枚举时,它会将其序列化为复杂对象。例如对象 Color:

public class Color : Enumeration<Color, int>
{
    public static readonly Color Red = new Color(1, "Red");
    public static readonly Color Blue = new Color(2, "Blue");
    public static readonly Color Green = new Color(3, "Green");

    private Color(int value, string displayName) : base(value, displayName) { }
}

将序列化为

{ 
    "_value": 2, 
    "_displayName": "Something" 
}

在像这样的复杂对象中:

public class OtherClass
{
    public Color Color {get; set;}
    public string Description {get; set;}
}

它将像这样序列化:

{
    "Description" : "Other Description",
    "Color" :
    { 
        "_value": 2, 
        "_displayName": "Something" 
    }
}

有什么方法可以使 json 像这样转换序列化复杂对象:

{
    "Description" : "Other Description",
    "Color" : 2
}

我可以使用枚举中的 FromValue 方法从值中创建正确的 Color 对象 class。我似乎无法使 json convert 将 属性 值作为 Color 对象的 "value"。

我可以用什么方式编写转换器的 WriteJson 和 Create 方法来实现这一点?

public class EnumerationConverter : JsonCreationConverter<IEnumeration>
        {
            public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
            {
            }

            protected override IEnumeration Create(Type objectType, JObject jObject)
            {
            }
        }

您可以像这样为您的 Headspring.Enumeration<T, int> 派生的 class(es) 创建一个通用转换器:

class EnumerationConverter<T> : JsonConverter where T : Headspring.Enumeration<T, int>
{
    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(T);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        int val = Convert.ToInt32(reader.Value);
        return Headspring.Enumeration<T, int>.FromValue(val);
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        var enumVal = (Headspring.Enumeration<T, int>)value;
        writer.WriteValue(enumVal.Value);
    }
}

要使用转换器,请将 [JsonConverter] 属性添加到您的枚举 class(es),如下所示:

[JsonConverter(typeof(EnumerationConverter<Color>))]
public class Color : Headspring.Enumeration<Color, int>
{
    public static readonly Color Red = new Color(1, "Red");
    public static readonly Color Blue = new Color(2, "Blue");
    public static readonly Color Green = new Color(3, "Green");

    private Color(int value, string displayName) : base(value, displayName) { }
}

这是一个往返演示:https://dotnetfiddle.net/CZsQab