如何使用c#删除json中的NULL？

var jsonObject = JsonConvert.DeserializeObject(jsonString);

private void RemoveNullProperties(JObject obj)
{
    foreach (var property in obj.Properties().ToList())
    {
        if (property.Value.Type == JTokenType.Object)
        {
            RemoveNullProperties((JObject)property.Value);
        }
        else if (property.Value.Type == JTokenType.Array)
        {
            foreach (var item in property.Value.Children().ToList())
            {
                if (item.Type == JTokenType.Object)
                {
                    RemoveNullProperties((JObject)item);
                }
            }
        }
        else if (property.Value.Type == JTokenType.Null)
        {
            property.Remove();
        }
    }
}

RemoveNullProperties((JObject)jsonObject);

var modifiedJsonString = JsonConvert.SerializeObject(jsonObject);