---

<Window x:Class="primeapp.Pages.LoginWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Авторизация"
        Height="300"
        Width="400"
        WindowStartupLocation="CenterScreen"
        ResizeMode="NoResize">
    <Grid Margin="20">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <TextBlock Text="Авторизация менеджера"
                   FontSize="20"
                   FontWeight="Bold"
                   HorizontalAlignment="Center"
                   Margin="0,0,0,20"/>

        <TextBlock Grid.Row="1"
                   Text="Логин"
                   Margin="0,0,0,5"/>
        <TextBox x:Name="LoginTb"
                 Grid.Row="1"
                 Margin="0,25,0,15"
                 Height="30"/>

        <TextBlock Grid.Row="2"
                   Text="Пароль"
                   Margin="0,0,0,5"/>
        <PasswordBox x:Name="PasswordPb"
                     Grid.Row="2"
                     Margin="0,25,0,20"
                     Height="30"/>

        <Button Grid.Row="3"
                Content="Войти"
                Height="35"
                Width="120"
                HorizontalAlignment="Center"
                Click="LoginBtn_Click"/>
    </Grid>
</Window>






using System.Linq;
using System.Windows;
using primeapp.Database;

namespace primeapp.Pages
{
    public partial class LoginWindow : Window
    {
        public LoginWindow()
        {
            InitializeComponent();
            ConnectToDb.conDb = new primebaseEntities();
        }

        private void LoginBtn_Click(object sender, RoutedEventArgs e)
        {
            string login = LoginTb.Text.Trim();
            string password = PasswordPb.Password.Trim();

            if (string.IsNullOrWhiteSpace(login) || string.IsNullOrWhiteSpace(password))
            {
                MessageBox.Show("Введите логин и пароль", "Ошибка", MessageBoxButton.OK, MessageBoxImage.Warning);
                return;
            }

            var currentUser = ConnectToDb.conDb.Users.FirstOrDefault(x =>
                x.Login == login && x.Password == password);

            if (currentUser == null)
            {
                MessageBox.Show("Неверный логин или пароль", "Ошибка", MessageBoxButton.OK, MessageBoxImage.Error);
                return;
            }

            MainWindow mainWindow = new MainWindow();
            mainWindow.Show();
            Close();
        }
    }
}