如何使用JsonConverter仅序列化类的继承属性 [英] How to serialize only inherited properties of a class using a JsonConverter
问题描述
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,所以我改用了自定义JsonConverter.
I'm trying to serialize only the inherited properties of a class using json.net. I'm aware of the [JsonIgnore] attribute, but I only want to do ignore them on certain occasion, so I used a custom JsonConverter instead.
这是我的课程:
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.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.
When doing a simple o.WriteTo(writer); it give the same result as not using a converter. When iterating through properties and using WriteTo on the properties, it works fine for base type (int, string, etc), but I'm having problem with collections.
预期:
{
"Type": 128,
"Time": [
1,
2,
],
"Pattern": 1,
"Description": ""
}
知道:
"Type": 128,
"Time": [
1,
2,
]"Pattern": 1,
"Description": ""
如您所见,集合缺少,"和结束行部分.我也缺少整个对象的全局{}.
As you can see, the collection is missing the "," and endline portion. I'm also missing the global { } for the whole object.
我在做正确的事情吗?有没有更简单的方法来获得我想要的结果?
I am doing things the correct way? Is there an easier way to get the result I want?
推荐答案
不确定您的代码为什么不起作用(可能是Json.NET错误?).相反,您可以从JObject
中删除不需要的属性,并在一个调用中将整个内容写入:
Not sure why your code doesn't work (maybe a Json.NET bug?). Instead, you can remove the properties you don't want from the JObject
and write the entire thing in one call:
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);
}
或者,您可以创建自己的合同解析器并进行过滤基本属性和成员:
Alternatively, you could create your own contract resolver and filter out base properties and members:
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);
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