如何使用JsonConverter仅序列化类的继承属性

Question

我正在尝试仅使用json.net序列化类的继承属性。我知道[JsonIgnore]属性，但是我只想在某些情况下忽略它们，因此我改用了自定义JsonConverter。

这是我的课：

public class EverythingButBaseJsonConverter : JsonConverter
{
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        // Find properties of inherited class
        var classType = value.GetType();
        var classProps = classType.GetProperties(BindingFlags.DeclaredOnly | BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic).ToList();

        // Remove the overrided properties
        classProps.RemoveAll(t =>
        {
            var getMethod = t.GetGetMethod(false);
            return (getMethod.GetBaseDefinition() != getMethod);
        });

        // Get json data
        var o = (JObject)JToken.FromObject(value);

        // Write only properties from inhertied class
        foreach (var p in o.Properties().Where(p => classProps.Select(t => t.Name).Contains(p.Name)))
            p.WriteTo(writer);
    }

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

    public override bool CanRead
    {
        get { return false; }
    }

    public override bool CanConvert(Type objectType)
    {
        return true;
    }
}

做一个简单的o.WriteTo（writer）;
它给出的结果与不使用转换器的结果相同。当遍历属性并在属性上使用WriteTo时，它对于基本类型（int，字符串等）正常工作，但是集合存在问题。

预期：

{
  "Type": 128,
  "Time": [
    1,
    2,
  ],
  "Pattern": 1,
  "Description": ""
}

得到：

  "Type": 128,
  "Time": [
    1,
    2,
  ]"Pattern": 1,
  "Description": ""

如您所见，该集合缺少“，”和结束行部分。我也缺少整个对象的全局{}。

我在做正确的事情吗？有没有更简单的html" target="_blank">方法来获得我想要的结果？

Answer 1

不知道为什么您的代码不起作用（可能是Json.NET错误？）。相反，您可以从中删除不需要的属性，JObject并在一个调用中编写整个内容：

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        // Find properties of inherited class
        var classType = value.GetType();
        var classProps = classType.GetProperties(BindingFlags.DeclaredOnly | BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic).ToList();

        // Remove the overrided properties
        classProps.RemoveAll(t =>
        {
            var getMethod = t.GetGetMethod(false);
            return (getMethod.GetBaseDefinition() != getMethod);
        });

        // Get json data
        var o = (JObject)JToken.FromObject(value);

        // Remove all base properties
        foreach (var p in o.Properties().Where(p => !classProps.Select(t => t.Name).Contains(p.Name)).ToList())
            p.Remove();

        o.WriteTo(writer);
    }

另外，您可以创建自己的合同解析器并过滤基本属性和成员：

public class EverythingButBaseContractResolver : DefaultContractResolver
{
    protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
    {
        if (member.ReflectedType != member.DeclaringType)
            return null;
        if (member is PropertyInfo)
        {
            var getMethod = ((PropertyInfo)member).GetGetMethod(false);
            if (getMethod.GetBaseDefinition() != getMethod)
                return null;
        }
        var property = base.CreateProperty(member, memberSerialization);
        return property;
    }
}

然后像这样使用它：

        var settings = new JsonSerializerSettings { ContractResolver = new EverythingButBaseContractResolver() };
        var json = JsonConvert.SerializeObject(rootObject, Formatting.Indented, settings);