为非常简单的 类 调整和简化 DataContract 序列化？

Question

假设我有一个类型，其值可以完全由整数表示但具有验证逻辑，并且将在 Web API 中返回和接受。为了保持良好的代码并避免原始的痴迷，我可能会这样做：

public class FiscalPeriod
{
    public FiscalPeriod(int id)
    {
        if (!Validator.IsValidPeriod(id)) 
            throw new ArgumentException($"Invalid fiscal period ID '{id}'", nameof(id));
        Id = id;
    }

    public int Id { get; private set; }
    public override string ToString() => Id.ToString();
    public static implicit operator int(FiscalPeriod period) => period.Id;
}

然后，当 Web API 调用返回此类型时，它会序列化为 JSON 为：

"FiscalPeriod" : {"Id": 201601},

有没有办法强制它序列化为以下内容？

"FiscalPeriod" : 201601,

以便在客户端更容易将其作为普通数字处理？

Answer 1

您可以告诉 Json.Net 如何使用 JsonConverter 属性处理类型。

public class ViewModel
{
   public FiscalPeriod FiscalPeriod { get; set; }
}

public class FiscalPeriodConverter : JsonConverter
{
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        var fiscalPeriod = value as FiscalPeriod;
        writer.WriteStartObject();
        serializer.Serialize(writer, fiscalPeriod.Id);
        writer.WriteEndObject();
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }

    public override bool CanConvert(Type objectType)
    {
        return typeof(FiscalPeriod).IsAssignableFrom(objectType);
    }
}

[JsonConverter(typeof(FiscalPeriodConverter))]
public class FiscalPeriod
{
    public FiscalPeriod(int id)
    {
        if (!Validator.IsValidPeriod(id))
            throw new ArgumentException($"Invalid fiscal period ID '{id}'", nameof(id));
        Id = id;
    }

    public int Id { get; private set; }
    public override string ToString() => Id.ToString();
    public static implicit operator int(FiscalPeriod period) => period.Id;
}

http://www.newtonsoft.com/json/help/html/T_Newtonsoft_Json_JsonConverterAttribute.htm