protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            SetContentView(Resource.Layout.activity_service);
            selectedService = JsonConvert.DeserializeObject <BLL.Models.Service>(Intent.GetStringExtra("SelectedService") ?? string.Empty);
            Button btnSubmitService = FindViewById <Button>(Resource.Id.btnSubmitService);

            btnSubmitService.Click += BtnSubmitService_Click;
            if (selectedService != null)
            {
                btnSubmitService.Text = "Modyfikuj";
                FindViewById <EditText>(Resource.Id.editServiceName).Text          = selectedService.Name;
                FindViewById <EditText>(Resource.Id.editServiceDescription).Text   = selectedService.Description;
                FindViewById <EditText>(Resource.Id.editServicePrice).Text         = selectedService.Price.ToString();
                FindViewById <EditText>(Resource.Id.etExecutionTimeInMinutes).Text = selectedService.ExecutionTimeInMinutes.ToString();
                FindViewById <Button>(Resource.Id.btnDeleteService).Click         += BtnDeleteService_Click;
            }
            else
            {
                btnSubmitService.Text = "Dodaj";
                FindViewById <Button>(Resource.Id.btnDeleteService).Visibility = ViewStates.Gone;
            }
        }
        private void BtnSubmitService_Click(object sender, EventArgs e)
        {
            string textServiceName            = FindViewById <EditText>(Resource.Id.editServiceName).Text;
            string textServiceDescription     = FindViewById <EditText>(Resource.Id.editServiceDescription).Text;
            string textServicePrice           = FindViewById <EditText>(Resource.Id.editServicePrice).Text;
            string testExecutionTimeInMinutes = FindViewById <EditText>(Resource.Id.etExecutionTimeInMinutes).Text;

            if (string.IsNullOrWhiteSpace(textServiceName))
            {
                Toast.MakeText(Application.Context, "Uzupełnij nazwę usługi", ToastLength.Long).Show();
            }
            else if (string.IsNullOrWhiteSpace(textServiceDescription))
            {
                Toast.MakeText(Application.Context, "Uzupełnij opis usługi", ToastLength.Long).Show();
            }
            else if (string.IsNullOrWhiteSpace(textServicePrice))
            {
                Toast.MakeText(Application.Context, "Uzupełnij cenę", ToastLength.Long).Show();
            }
            else if (!decimal.TryParse(textServicePrice, out decimal servicePrice))
            {
                Toast.MakeText(Application.Context, "Nie poprawna cena", ToastLength.Long).Show();
            }
            else if (!int.TryParse(testExecutionTimeInMinutes, out int executionTimeInMinutes))
            {
                Toast.MakeText(Application.Context, "Nie poprawny czas wykonywania", ToastLength.Long).Show();
            }
            else
            {
                OperationResult operationResult;
                if (selectedService != null)
                {
                    selectedService.Name                   = textServiceName;
                    selectedService.Description            = textServiceDescription;
                    selectedService.Price                  = servicePrice;
                    selectedService.ExecutionTimeInMinutes = executionTimeInMinutes;
                    operationResult = serviceService.EditService(selectedService);
                }
                else
                {
                    selectedService = new BLL.Models.Service
                    {
                        Name                   = textServiceName,
                        Description            = textServiceDescription,
                        Price                  = servicePrice,
                        ExecutionTimeInMinutes = executionTimeInMinutes
                    };
                    operationResult = serviceService.AddService(selectedService);
                }

                if (operationResult.ResultCode == ResultCode.Successful)
                {
                    SetResult(Result.Ok);
                    this.Finish();
                }
                else
                {
                    Toast.MakeText(Application.Context, operationResult.Message, ToastLength.Long).Show();
                }
            }
        }