How to Ignore a Property in Class If Null, Using Json.Net

How to ignore a property in class if null, using json.net

As per James Newton King: If you create the serializer yourself rather than using JavaScriptConvert there is a NullValueHandling property which you can set to ignore.

Here's a sample:

JsonSerializer _jsonWriter = new JsonSerializer {
                                 NullValueHandling = NullValueHandling.Ignore
                             };

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Alternatively, as suggested by @amit

JsonConvert.SerializeObject(myObject, 
                            Newtonsoft.Json.Formatting.None, 
                            new JsonSerializerSettings { 
                                NullValueHandling = NullValueHandling.Ignore
                            });

Ignoring null fields in Json.net

Yes you need to use JsonSerializerSettings.NullValueHandling = NullValueHandling.Ignore.

But because structs are value types you need to mark Field2, Field3 nullable to get the expected result:

public struct structA
{
    public string Field1;
    public structB? Field2;
    public structB? Field3;
}

Or just use classes instead of structs.

Documentation: NullValueHandling Enumeration

Ignore property when null using the new Net Core 3.0 Json

This was fixed on .Net 5

[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]

See the updates below

https://github.com/dotnet/runtime/issues/41313

https://github.com/dotnet/runtime/issues/30687

Json.NET Ignore null values in dictionary

I would just filter out the null values from the original dictionary with LINQ and serialize the filtered dictionary:

using System;
using System.Collections.Generic;
using System.Linq;
using Newtonsoft.Json;

namespace JsonSerialize {
    public static class Program {
        private static Dictionary<string, string> dict = new Dictionary<string, string> {
            ["A"] = "Some text",
            ["B"] = null
        };

        public static void Main(string[] args) {
            var filtered = dict
                .Where(p => p.Value != null)
                .ToDictionary(p => p.Key, p => p.Value);

            var json = JsonConvert.SerializeObject(filtered, Formatting.Indented);

            Console.WriteLine (json);
        }
    }
}

Which gives:

{
  "A": "Some text"
}

Need to ignore NULL values when deserializing JSON

NullValueHandling.Ignore will ignore null values for the relevant property of your model when serializing.

When deserialzing, you might consider deserializing to an IEnumerable<ChartData> then using Linq to filter out the objects you don't want, based on what is, after all, custom logic: "exclude objects that have close == null".

E.g. (untested air code):

var data = JsonConvert.DeserializeObject<IEnumerable<ChartData>>(content,jsonSettings)
    .Where(cd => cd.close != null)
    ;

var observableData = new ObservableCollection<ChartData>(data);

How to ignore null fields in json serialization (Newtonsoft.Json)?

I deleted the file and recreated it instead of overwriting it. Source object was exactly the same. I was probably not overwriting the file correctly.

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