RegAuth/CreateAuthorize/MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace CreateAuthorize
{

    public partial class MainWindow : Window
    {
        gr682_rdnEntities db;
        public MainWindow()
        {
            InitializeComponent();
            db = new gr682_rdnEntities();
        }

      
        private void AuthorizaationClick(object sender, RoutedEventArgs e)
        {
            if (login.Text == "" || password.Password == "")
            {
                MessageBox.Show("Ошибка поле пусное");
                return;
            }
            if (db.User.Select(item => item.Login + " " + item.Password).Contains(login.Text + " " + password.Password))
            {
                MessageBox.Show("Вы авторезированы");
            }
            else
            {
                MessageBox.Show("Ошибка логина/пароля");
            }
        }
        private void RegistrationClick(object sender, RoutedEventArgs e)
        {
            Window1 rw = new Window1();
            rw.Show();
            this.Close();
        }
        private void ButtonEnter_Clic()
        {
            Auth(login.Text, password.Password);
        }
        public bool Auth(string login, string password)
        {
            if(string.IsNullOrEmpty(login) || string.IsNullOrEmpty(password))
            {
                MessageBox.Show("Введите логин или пароль");
                return false;
            }
            using(var db = new gr682_rdnEntities())
            {
                var user = db.User
                    .AsNoTracking()
                    .FirstOrDefault(u => u.Login == login && u.Password == password);
                if(user == null)
                {
                    MessageBox.Show("Тип с такими данными не найден!");
                    return false;
                }
                MessageBox.Show("Успешно найден");
                return true;
            }

        }


    }
}