private void btn1_Click(object sender, RoutedEventArgs e)
        {
            //string constr = @"Data Source=DESKTOP-GM2O70F\MSSQLDEV;Initial Catalog=GosSoviet;Integrated Security=True";
            SQLWork work = new SQLWork();

            if (work.FindUser(tbLog.Text, tbPass.Text))
            {
                Loading ld = new Loading();
                this.Hide();
                ld.Show();
            }
            else
            {
                MessageBox.Show("Неправильный логин или пороль", "", MessageBoxButton.OK, MessageBoxImage.Exclamation);
            }
        }
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            if (string.IsNullOrEmpty(tbSurname.Text) ||
                string.IsNullOrEmpty(tbFathername.Text) ||
                string.IsNullOrEmpty(tbName.Text) ||
                string.IsNullOrEmpty(tbLogin.Text) ||
                string.IsNullOrEmpty(tbPass.Text) ||
                dataPickerDeputy.SelectedDate == null)
            {
                MessageBox.Show("Введите все данные");
            }
            else if (work.FindUser(tbLogin.Text))
            {
                MessageBox.Show("Такой логин уже существует");
            }
            else
            {
                Deputy deputy = new Deputy
                {
                    Surname    = tbSurname.Text,
                    Fathername = tbFathername.Text,
                    Name       = tbName.Text,
                    Login      = tbLogin.Text,
                    Password   = tbPass.Text,
                    Birthday   = dataPickerDeputy.SelectedDate,
                    Dostup     = (bool)checkBoxDeputy.IsChecked
                };
                db.Add(deputy);
                db.SaveChanges();
                MessageBox.Show("Депутат успешно добавлен");

                tbSurname.Text                = "";
                tbFathername.Text             = "";
                tbName.Text                   = "";
                tbLogin.Text                  = "";
                dataPickerDeputy.SelectedDate = null;
                tbPass.Text                   = "";
            }
        }