/// <summary> Konstruktor uruchamiany w celu dodania nowego wpisu </summary>
        public CityEditViewModel(string connectionString)
        {
            this.SaveButtonClick = new GalaSoft.MvvmLight.Command.RelayCommand(() =>
            {
                try
                {
                    if (this.PostalCodeTextBoxContent == null || this.CityNameTextBoxContent == null)
                    {
                        MessageBox.Show("Wypełnij pole z kodem pocztowym i nazwą");
                    }
                    else
                    {
                        using (var ctx = new molkomEntities())
                        {
                            ctx.Cities.Add(GetCityObject());
                            ctx.SaveChanges();
                            GlobalVariables.refreshMainWindowFlag = 1;
                            RequestClose?.Invoke(this, EventArgs.Empty);
                        }
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            });

            SetDefaultDateFormat();
        }
        /// <summary> Zapisanie zmian edytowanego elementu do bazy danych </summary>
        public void SaveEntry()
        {
            try
            {
                using (var ctx = new molkomEntities())
                {
                    var address = ctx.Addresses.FirstOrDefault(x => x.id == this.idOfEntity);

                    if (address != null)
                    {
                        address.name        = this.NameTextBoxContent;
                        address.surname     = this.SurnameTextBoxContent;
                        address.phoneNumber = this.PhoneTextBoxContent;
                        address.birthdate   = new DateTime(Int32.Parse(this.YearOfBirthTextBoxContent), this.MonthOfBirthSelectedIndex + 1, Int32.Parse(this.DayOfBirthTextBoxContent));
                        address.status      = this.Status;
                        if (GetIdOfSelectedCityItem() != 0)
                        {
                            address.city = GetIdOfSelectedCityItem();
                        }
                        address.dateOfUpdate = System.DateTime.Now;

                        ctx.SaveChanges();
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        /// <summary> Zapisanie zmian edytowanego elementu do bazy danych </summary>
        public void SaveEntry()
        {
            try
            {
                using (var ctx = new molkomEntities())
                {
                    var address = ctx.Cities.FirstOrDefault(x => x.id == this.idOfEntity);

                    if (address != null)
                    {
                        address.postalCode     = PostalCodeTextBoxContent;
                        address.name           = CityNameTextBoxContent;
                        address.dateOfCreation = System.DateTime.Now;
                        address.dateOfUpdate   = System.DateTime.Now;

                        ctx.SaveChanges();
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        /// <summary> Konstruktor uruchamiany w celu dodania nowego wpisu </summary>
        public AddressEditViewModel(string connectionString)
        {
            this.SaveButtonClick = new GalaSoft.MvvmLight.Command.RelayCommand(() =>
            {
                try
                {
                    if (this.NameTextBoxContent == null || this.SurnameTextBoxContent == null)
                    {
                        MessageBox.Show("Wypełnij pole z imieniem i nazwiskiem");
                    }
                    else
                    {
                        using (var ctx = new molkomEntities())
                        {
                            ctx.Addresses.Add(GetAddressObject());
                            ctx.SaveChanges();
                            GlobalVariables.refreshMainWindowFlag = 1;
                            RequestClose?.Invoke(this, EventArgs.Empty);
                        }
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            });

            this.Status                      = true;
            this.DateOfCreation              = System.DateTime.Now;
            this.DateOfUpdate                = System.DateTime.Now;
            this.CitiesComboBoxContent       = new ObservableCollection <string>();
            this.MonthOfBirthComboBoxContent = new ObservableCollection <string>();
            SetDefaultDateFormat();
            LoadMonthsComboBoxContent();
            LoadCitiesComboBoxContent(connectionString);
        }