cn.jpush.api.device.DeviceClient.ToJson C# (CSharp) Method

        public string ToJson(Dictionary<String, String[]> registration)
        {
            jSetting = new JsonSerializerSettings();
            jSetting.NullValueHandling = NullValueHandling.Ignore;
            jSetting.DefaultValueHandling = DefaultValueHandling.Ignore;
            return JsonConvert.SerializeObject(registration, jSetting);
        }