NewtonSoft反序列化中的处理错误不起作用

Question

I'm trying to handle deserialization error, but even if I'm able to reach error handling function and set Handled property to true then error is throwing to the main function.

Models:

public class PriceValidity
{
    public Date EndDate { get; set; }

    public Date StartDate { get; set; }

    [OnError]
    internal void OnError(StreamingContext context, ErrorContext errorContext)
    {
        errorContext.Handled = true;
    }
}

public class Date
{
    [JsonProperty("$date")]
    public DateTime Value { get; set; }
}

Calling deserializer:

private void ParseMessage<T>(string message) where T: new()
{
    var result = new T();
    var jsonSerializer = new Newtonsoft.Json.JsonSerializer();

    using (var reader = new StringReader(message))
    using (var jsonReader = new JsonTextReader(reader))
    {
        result = jsonSerializer.Deserialize<T>(jsonReader);
    };
}

JSON:

{  
   "StartDate":{  
      "$date":"2018-05-07T00:00:00.000Z"
   },
   "EndDate":{  
      "$date":{  
         "$numberLong":"253402214400000"
      }
   }
}

Error:

After parsing a value an unexpected character was encountered: :. Path 'EndDate.$date',

I don't want to handle also $numberLong scenario but just skip it.

Answer 1

Not an answer but a workaround: Move the error handling to serializer options:

    private T ParseMessage<T>(string message) where T : new() => 
        JsonConvert.DeserializeObject<T>(message, new JsonSerializerSettings
    {
        Error = (object sender, ErrorEventArgs args) => { args.ErrorContext.Handled = true; }
    });

From Chetan Ranpariya's comment:

Having OnError in entity class is useful when there is a change of exception being thrown from the Entity class itself as explained for the Roles property of the PersonError class here: https://www.newtonsoft.com/json/help/html/SerializationErrorHandling.htm

Answer 2

Finally I found solution. To handle such scenario I've had to create Json Converter.

public class JMSDateTimeConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return true;
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        try
        {
            JToken token = JToken.Load(reader);

            if (token.Type == JTokenType.Object && GetAllChildresnCount(token) == 2)
            {
                return token.ToObject(objectType);
            }
            else
            {
                return null;
            }
        }
        catch (Exception ex)
        {
            return null;
        }
        finally
        {
        }
    }

    private int GetAllChildresnCount(JToken token)
    {
        var container = token as JContainer;

        if (container == null)
        {
            return 0;
        }

        var count = container.Count;

        foreach (JToken subToken in container)
        {
           count += GetAllChildresnCount(subToken);
        }

        return count;
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        serializer.Serialize(writer, value);
    }
}

Now works fine.