private void CityPicker_OnTap(object sender, System.Windows.Input.GestureEventArgs e)
 {
     if (this.VM.Country == null || this.VM.Country.id < 1L)
     {
         return;
     }
     CityPickerUC.Show(this.VM.Country.id, this.VM.City, true, (Action <City>)(city => this.VM.City = city), null);
 }
        public void ChooseCity()
        {
            long countryId = this._countryId;

            VKClient.Common.Backend.DataObjects.City selectedCity = new VKClient.Common.Backend.DataObjects.City();
            selectedCity.id = this._cityId;
            int num = 1;
            Action <VKClient.Common.Backend.DataObjects.City> cityPickedCallback = (Action <VKClient.Common.Backend.DataObjects.City>)(c =>
            {
                this._cityId = c.id;
                this.City    = c.id != 0L ? c.name :  null;
            });

            // ISSUE: variable of the null type

            CityPickerUC.Show(countryId, selectedCity, num != 0, cityPickedCallback, null);
        }