public static async Task GetMarkAttendance(MarkAttendance markAttendance, Action <MarkAttendanceResponse> successCallback, Action <ResponseBase> errorCallback) { RestRequest request = new RestRequest("/lms/api/markattendance", Method.PUT); MarkAttendanceRequest requestData = new MarkAttendanceRequest() { UniqueAppId = App.UniqueAppId, MarkAttendanceData = markAttendance }; Debug.WriteLine(JsonConvert.SerializeObject(requestData)); request.AddBody(requestData); MarkAttendanceResponse response = await APIServiceProvider.ServiceProvider.Execute <MarkAttendanceResponse> (request); if ((response != null) && (response.ResponseCode == "1000")) { successCallback?.Invoke(response); } else { errorCallback?.Invoke((ResponseBase)response); } }