public async Task <List <OpponentAdvert> > GetFilteredOpponentAdverts(FilterModelOpponentAdverts filterModel)
        {
            try
            {
                //oginModel loginModel = new LoginModel();
                //CrossSecureStorage.Current.DeleteKey("token");
                var input  = $"https://www.harbisaha.com/api/OpponentAdvert/OpponentAdvertsFilterDetailed";
                var client = await GetFirstClient();

                client.DefaultRequestHeaders.Accept.Clear();
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                string serializedObject = JsonConvert.SerializeObject(filterModel);

                HttpContent         contentPost = new StringContent(serializedObject, Encoding.UTF8, "application/json");
                HttpResponseMessage response    = await client.PostAsync(input, contentPost);

                if (response.IsSuccessStatusCode)
                {
                    var data = await response.Content.ReadAsStringAsync();

                    List <OpponentAdvert> modelToReturn = JsonConvert.DeserializeObject <List <OpponentAdvert> >(data);
                    return(modelToReturn);
                }
                else
                {
                    return(null);
                }
            }
            catch (Exception)
            {
                throw;
            }
        }
        private async void FilterThem()
        {
            FilterModelOpponentAdverts filterModel = new FilterModelOpponentAdverts();
            ActivityControl            ctrl        = new ActivityControl();

            ctrl.MakeVisible(ActivityLayout, activity);
            adverts.Clear();
            viewModels.Clear();

            if (pickerCities.SelectedItem == null)
            {
                filterModel.City = "Tüm Şehirler";
            }
            else
            {
                filterModel.City = pickerCities.SelectedItem as string;
            }
            if (pickerTowns.SelectedItem == null)
            {
                filterModel.Town = "Tüm İlçeler";
            }
            else
            {
                filterModel.Town = pickerTowns.SelectedItem as string;
            }
            filterModel.Date = datePickerDate.Date;
            filterModel.Time = timePicker1.Time;
            adverts          = await serviceAdvert.GetFilteredOpponentAdverts(filterModel);

            try
            {
                if (adverts == null)
                {
                    lblErrorMessage.IsVisible = true;
                }
                else
                {
                    foreach (OpponentAdvert adv in adverts)
                    {
                        viewModels.Add(new OpponentAdvertMenuViewModel()
                        {
                            Advert = adv
                        });
                    }

                    lstOpponentAdverts.ItemsSource = viewModels;
                    ctrl.MakeUnVisible(ActivityLayout, activity);
                }
            }
            catch (Exception ex)
            {
                await  DisplayAlert("Warn", ex.Message, "OK");
            }
        }