[JsonProperty(NullValueHandling=NullValueHandling.Ignore)]

// or

[JsonProperty("property_name", NullValueHandling=NullValueHandling.Ignore)]

​

// or for all properties in a class

[JsonObject(ItemNullValueHandling = NullValueHandling.Ignore)]

 // Temporary file

var jsonTempFilePath = FileUtils.CreateTmpFile();

​

using (var fs = File.Open(jsonTempFilePath, FileMode.Open))

using (var sw = new StreamWriter(fs))

using (var jw = new JsonTextWriter(sw))

{

    var serializer = new JsonSerializer()

    {

        // Ignore null properties

        NullValueHandling = NullValueHandling.Ignore,

    };

    serializer.Serialize(jw, output);

}