private void BtnUpdateBook_Click(object sender, RoutedEventArgs e) { if (!Validation()) { return; } Book newBook = new Book { Id = bk.Id, Name = tbBookName.Text, Author = tbAuthorName.Text, CountNow = Convert.ToInt32(tbBookCount.Text), Count = (Convert.ToInt32(tbBookCount.Text) - bk.CountNow) + bk.Count, Price = Convert.ToDecimal(tbPrice.Text) }; dr.UpdateBooks(newBook); btnAddBook.Visibility = Visibility.Visible; btnUpdateBook.Visibility = Visibility.Hidden; btnDeleteBook.Visibility = Visibility.Hidden; ResetTextBox(); FillDG(); }