自定义JSONCONVERTER不要求嵌套属性

Question

我有一个班级员工，经理属性本身是类型员工

public class Employee
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public Employee Manager { get; set; }
    public IList<string> Roles { get; set; }
}

我想为员工类型创建一个自定义的jsonconverter。

public class TestJsonConverter : JsonConverter
{
    public TestJsonConverter()
    {
    }
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        JToken t = JToken.FromObject(value);
        if (t.Type != JTokenType.Object)
        {
            t.WriteTo(writer);
        }
        else
        {
            JObject o = (JObject)t;
            IList<string> propertyNames = o.Properties().Select(p => p.Name).ToList();
            o.AddFirst(new JProperty("Keys", new JArray(propertyNames)));
            o.WriteTo(writer);
        }
    }
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotImplementedException("Unnecessary because CanRead is false. The type will skip the converter.");
    }
    public override bool CanConvert(Type objectType)
    {
        return (objectType == typeof(Employee));
    }
    public override bool CanRead
    {
        get { return false; }
    }
}

违规者是

class ContractResolver : DefaultContractResolver
{
    protected override JsonObjectContract CreateObjectContract(Type objectType)
    {
        JsonObjectContract contract = base.CreateObjectContract(objectType);
        if (objectType == typeof(Employee))
        {
            contract.Converter = new TestJsonConverter();
        }
        return contract;
    }
}

当我尝试序列化员工对象时，自定义JSONCONVERTER仅适用于顶级员工对象，而不是嵌套管理器属性（也是员工类型的嵌套管理属性：

）

JsonSerializerSettings settings = new JsonSerializerSettings();
settings.ContractResolver = new ContractResolver();
string json = JsonConvert.SerializeObject(employee, Formatting.Indented, settings);

Answer 1

我认为您遇到了相同的问题自定义JSONCONVERTER WERTINJSON不会更改子专业的序列化：

您的转换器没有应用于子对象的原因是因为jtoken.fromobject（）在内部使用序列化器的新实例，该实例不知道您的转换器。

所提供的解决方案应适应您的案件。

Answer 2

，因此JsonConverter从根节点开始运行一次。您需要浏览此JSON对象树并自行更新。

不确定这是您打算实现的目标，但我自己尝试了，您可以决定这是否适合您。

public class TestJsonConverter : JsonConverter
{
    public TestJsonConverter()
    {
    }
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        JToken t = JToken.FromObject(value);
        if (t.Type != JTokenType.Object)
        {
            t.WriteTo(writer);
        }
        else
        {
            JObject root = (JObject)t;
            var stack = new Stack<JObject>();
            stack.Push(root);
            while (stack.Any())
            {
                var current = stack.Pop();
                var propertyNames = current.Properties().Select(p => p.Name).ToArray();
                current.AddFirst(new JProperty("Keys", new JArray(propertyNames)));
                var nestedObjects = current.Properties().Where(p => p.Value.Type == JTokenType.Object).ToArray();
                foreach (var nestedObj in nestedObjects)
                {
                    stack.Push((JObject)nestedObj.Value);
                }
            }
            root.WriteTo(writer);
        }
    }
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotImplementedException("Unnecessary because CanRead is false. The type will skip the converter.");
    }
    public override bool CanConvert(Type objectType)
    {
        return (objectType == typeof(Employee));
    }
    public override bool CanRead
    {
        get { return false; }
    }
}