ProjectLib/ProjectLibrary/Forms/FOrders.cs

using System;
using System.Windows.Forms;
using ProjectLibrary.Entites;

namespace ProjectLibrary.Forms
{
    public partial class FOrders : Form
    {
        private Orders _order;
        private Book_Orders _bookOrder;

        public FOrders(Orders order, Book_Orders bookOrder)
        {
            InitializeComponent();
            _order = order;
            _bookOrder = bookOrder;
            LoadOrderData();
        }

        private void LoadOrderData()
        {
            txtOrderID.Text = _order.Id.ToString();
            txtOrderDate.Text = _order.OrderDate.ToString();
            txtReturnDate.Text = _order.ReturnDate.ToString();
            txtReaderID.Text = _order.ReaderID.ToString();
            txtBookID.Text = _bookOrder.BookID.ToString();
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            // Создание обновленных данных
            var updatedOrder = Orders.CreateEntity(
                int.Parse(txtOrderID.Text),
                int.Parse(txtOrderDate.Text),
                int.Parse(txtReturnDate.Text),
                int.Parse(txtReaderID.Text)
            );

            var updatedBookOrder = Book_Orders.CreateEntity(
                int.Parse(txtBookID.Text),
                int.Parse(txtOrderID.Text)
            );

            // Обновление объектов
            _order = updatedOrder;
            _bookOrder = updatedBookOrder;

            MessageBox.Show("Данные успешно сохранены!");
        }

        private void buttonCancel_Click_Click(object sender, EventArgs e)
        {

        }
    }
}