ErmolinExamApplication/Auth.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 ModuleExam
{
    /// <summary>
    /// Логика взаимодействия для Auth.xaml
    /// </summary>
    public partial class Auth : Page
    {
        ExamEntities DB = new ExamEntities();

        public Auth()
        {
            InitializeComponent();
        }

        private void MakeAuth(object sender, RoutedEventArgs e)
        {
            int id = CheckOnExisting(Email.Text, Pass.Password);
            if (id !=-1)
            {
                MainFrame.MFrame.Navigate(new ActivityPage(id));
            }
            else 
            {
                MessageBox.Show("Вас не в системе");
            }
        }

        public int CheckOnExisting(string Mail, string Password)
        {
            users user = new users();
            user = DB.users.Where(x => x.email == Mail && x.password == Password).FirstOrDefault();
            if(user != null)
            {
                return user.id;
            }
            else { return -1; }
        }
    }
}