Progect/ListHotels.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;
using WpfApp1.Entities;

namespace WpfApp1
{
    /// <summary>
    /// Логика взаимодействия для ListHotels.xaml
    /// </summary>
    public partial class ListHotels : Page
    {
        public ListHotels()
        {
            InitializeComponent();
            //DGridHotels.ItemsSource = new Entities.user20Entities().User.ToList();
        }
        private void BtnEdit_Click(object sender, RoutedEventArgs e)
        {
            Manager.MainFrame.Navigate(new AddEditPage((sender as Button).DataContext as User));
        }

        private void BtnAdd_Click(object sender, RoutedEventArgs e)
        {
            Manager.MainFrame.Navigate(new AddEditPage(null));
        }

        private void BtnDelete_Click(object sender, RoutedEventArgs e)
        {
            var usersForRemoving = DGridHotels.SelectedItems.Cast<User>().ToList();
            if (MessageBox.Show($"Вы точно хотите удалить следующие {usersForRemoving.Count()} данные?", "Внимание!",
                MessageBoxButton.YesNo, MessageBoxImage.Question) == MessageBoxResult.Yes)
            {
                try
                {
                    usersForRemoving.ForEach(user => { user.IsDeleted = true;});
                    user20Entities.GetContext().SaveChanges();
                    MessageBox.Show("Данные удалены!");

                    DGridHotels.ItemsSource = user20Entities.GetContext().User.Where(u => u.IsDeleted == false).ToList();
                }
                catch (Exception ex)
                {
                    var inner = ex.InnerException;
                    MessageBox.Show(inner.ToString());
                }
            }
        }

        private void Page_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            if (Visibility == Visibility.Visible)
            {
                user20Entities.GetContext().ChangeTracker.Entries().ToList().ForEach(p => p.Reload());
                DGridHotels.ItemsSource = user20Entities.GetContext().User.ToList();
            }
        }
    }
}