Kusach/Kusach/RegWindow.xaml.cs

using System;
using System.Linq;
using System.Windows;

namespace Kusach
{
    /// <summary>
    /// Логика взаимодействия для RegWindow.xaml
    /// </summary>
    public partial class RegWindow : Window
    {
        public RegWindow()
        {
            InitializeComponent();
        }

        private void RegButton_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                if (logbox.Text == "" || passbox.Text == "")
                    MessageBox.Show("Поля не могут быть пустыми.");
                else if (cnt.db.Dispatcher.Select(item => item.Login).Contains(logbox.Text))
                    MessageBox.Show("Данный логин уже занят");
                else
                {
                    Dispatcher newUser = new Dispatcher()
                    {
                        IdDispatcher = cnt.db.Dispatcher.Select(p => p.IdDispatcher).DefaultIfEmpty(0).Max() + 1,
                        Login = logbox.Text,
                        Password = Encrypt.GetHash(passbox.Text),
                        Surname = FNameBox.Text,
                        Name = LNameBox.Text,
                        Patronymic = MNameBox.Text,
                        Birthday = Convert.ToDateTime(BirthdayBox.Text),
                        PhoneNumber = PhoneBox.Text
                    };
                    cnt.db.Dispatcher.Add(newUser);
                    cnt.db.SaveChanges();
                    MessageBox.Show("Вы успешно зарегистрировались");
                    MainWindow mw = new MainWindow();
                    mw.Show();
                    this.Close();
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show($"Произошла ошибка. : {ex}");
            }
        }

        private void BackButton_Click(object sender, RoutedEventArgs e)
        {
            LogWindow lw = new LogWindow();
            lw.Show();
            this.Close();
        }
    }
}