BookStore_NET5/BookStore/MainWindow.xaml.cs

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

namespace BookStore
{
    public partial class MainWindow : Window
    {
        BookStoreContext _context = new BookStoreContext();

        public MainWindow() { InitializeComponent(); Load(); }

        public void Load() { BooksGrid.ItemsSource = _context.Books.ToList(); }

        private void BtnInsert_Click(object sender, RoutedEventArgs e) { BIC(); }
        public void BIC()
        {
            if (!decimal.TryParse(TbPrice.Text, out decimal price)) { return; }
            Book book = new Book()
            {
                Name = TbName.Text,
                Price = price,
                Author = TbAuthor.Text,
                Category = TbCategory.Text
            };
            _context.Books.Add(book); _context.SaveChanges(); Load();
        }

        private void BtnUpdate_Click(object sender, RoutedEventArgs e) { BUC(); }
        public void BUC()
        {
            if (BooksGrid.SelectedItem is Book selectedBook)
            {
                if (!decimal.TryParse(TbPrice.Text, out decimal price)) { return; }
                selectedBook.Name = TbName.Text;
                selectedBook.Price = price;
                selectedBook.Author = TbAuthor.Text;
                selectedBook.Category = TbCategory.Text;
                _context.SaveChanges(); Load();
            }
        }

        private void BtnDelete_Click(object sender, RoutedEventArgs e) { BDC(); }
        public void BDC()
        {
            if (BooksGrid.SelectedItem is Book selectedBook)
            { _context.Books.Remove(selectedBook); _context.SaveChanges(); TbClear(); Load(); }
        }
        public void TbClear()
        { TbName.Text = ""; TbPrice.Text = ""; TbAuthor.Text = ""; TbCategory.Text = ""; }

        private void BooksGrid_SelectionChanged(object sender, SelectionChangedEventArgs e) { BGSC(); }
        public void BGSC()
        {
            if (BooksGrid.SelectedItem is Book selectedBook)
            {
                TbName.Text = selectedBook.Name;
                TbPrice.Text = selectedBook.Price.ToString();
                TbAuthor.Text = selectedBook.Author;
                TbCategory.Text = selectedBook.Category;
            }
        }
    }
}