Data from Two Tables in a Single DataGridView

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using MultiTableDatagrid.App_Data;

namespace MultiTableDatagrid
{
    public partial class frmMultiTable : Form
    {
        public frmMultiTable()
        {
            InitializeComponent();
        }

        private void frmMultiTable_Load(object sender, EventArgs e)
        {
            LoadDataIntoGrid();
            toolStripSave.Enabled = false;
            toolStripCancel.Enabled = false;
        }

        private void LoadDataIntoGrid()
        {
            List<OrdersDetails> ordersCollection = new List<OrdersDetails>();
            NORTHWINDEntities context = new NORTHWINDEntities();
            context.Connection.Open();
            int counter = context.Orders.Count();

            for (int i = 0; i < context.Orders.Count() - 1; i++)
            {
                // AutoMapper library can be used alternatively to perform this mapping.
                OrdersDetails item = new OrdersDetails();
                item.OrderID = context.Orders.ToList()[i].OrderID;
                item.OrderDate = context.Orders.ToList()[i].OrderDate;
                item.Quantity = context.Order_Details.ToList()[i].Quantity;
                item.Discount = context.Order_Details.ToList()[i].Discount;
                item.UnitPrice = context.Order_Details.ToList()[i].UnitPrice;
                item.ShipName = context.Orders.ToList()[i].ShipName;
                item.ShipAddress = context.Orders.ToList()[i].ShipAddress;
                item.ShipCity = context.Orders.ToList()[i].ShipCity;
                item.ShipCountry = context.Orders.ToList()[i].ShipCountry;
                item.ShippedDate = context.Orders.ToList()[i].ShippedDate;
                ordersCollection.Add(item);
                item = null;
            }

            gridbindingSource.DataSource = ordersCollection;
            multiTabledataGridView.DataSource = null;
            multiTabledataGridView.DataSource = gridbindingSource;
            multiTabledataGridView.Refresh();
            statusStrip1.Text = counter + " Item(s)";

            context.Connection.Close();
            context.Connection.Dispose();
            context.Dispose();
        }

        private void SaveDatafromGrid()
        {
            List<OrdersDetails> ordersCollection = new List<OrdersDetails>();
            NORTHWINDEntities context = new NORTHWINDEntities();
            ordersCollection = (List<OrdersDetails>) gridbindingSource.DataSource;
            context.Connection.Open();
            for (int i = 0; i < context.Orders.Count() - 1; i++)
            {
                // AutoMapper library can be used alternatively to perform this mapping.
                OrdersDetails item = new OrdersDetails();
                context.Orders.ToList()[i].OrderDate = ordersCollection.ToList()[i].OrderDate;
                context.Orders.ToList()[i].ShipName = ordersCollection.ToList()[i].ShipName;
                context.Orders.ToList()[i].ShipAddress = ordersCollection.ToList()[i].ShipAddress;
                context.Orders.ToList()[i].ShipCity = ordersCollection.ToList()[i].ShipCity;
                context.Orders.ToList()[i].ShipCountry = ordersCollection.ToList()[i].ShipCountry;
                context.Orders.ToList()[i].ShippedDate = ordersCollection.ToList()[i].ShippedDate;
                context.Order_Details.ToList()[i].Quantity = (short)ordersCollection.ToList()[i].Quantity;
                context.Order_Details.ToList()[i].Discount = ordersCollection.ToList()[i].Discount;
                context.Order_Details.ToList()[i].UnitPrice = ordersCollection.ToList()[i].UnitPrice;
            }

            gridbindingSource.DataSource = ordersCollection;
            multiTabledataGridView.DataSource = null;
            multiTabledataGridView.DataSource = gridbindingSource;
            multiTabledataGridView.Refresh();

            context.SaveChanges();
            context.Connection.Close();
            context.Connection.Dispose();
            context.Dispose();
        }

        private void DeleteDatafromGrid(int rowIndex)
        {
            List<OrdersDetails> ordersCollection; // = new List<OrdersDetails>();
            NORTHWINDEntities context = new NORTHWINDEntities();
            ordersCollection = (List<OrdersDetails>)gridbindingSource.DataSource;
            context.Connection.Open();
            int orderId;
            //Retrieve the OrderID
            orderId = ordersCollection.ElementAt(rowIndex).OrderID;
            var order = (from o in context.Orders
                         where o.OrderID == orderId
                         select o).First();

            //Delete the row from Order_Details child table first & then from the Orders table.
            if (!order.Order_Details.IsLoaded)
                order.Order_Details.Load();

            int counter = order.Order_Details.Count();
            for (int i = 0; i < counter; i++)
            {
                context.DeleteObject(order.Order_Details.First());
            }
            context.SaveChanges();

            context.DeleteObject(order);
            
            gridbindingSource.Remove(gridbindingSource.Current);
            multiTabledataGridView.Refresh();

            context.SaveChanges();
            context.Connection.Close();
            context.Connection.Dispose();
            context.Dispose();
        }

        private void multiTabledataGridView_CellBeginEdit(object sender, DataGridViewCellCancelEventArgs e)
        {
            toolStripSave.Enabled = true;
            toolStripCancel.Enabled = true;
        }

        private void multiTabledataGridView_CellEndEdit(object sender, DataGridViewCellEventArgs e)
        {
            multiTabledataGridView.EndEdit();
        }

        private void toolStripSave_Click(object sender, EventArgs e)
        {
            multiTabledataGridView.EndEdit();

            SaveDatafromGrid();
            
            toolStripSave.Enabled = false;
            toolStripCancel.Enabled = false;
        }

        private void toolStripDelete_Click(object sender, EventArgs e)
        {
            if (multiTabledataGridView.CurrentCell.RowIndex > -1)
            {
                DeleteDatafromGrid(multiTabledataGridView.CurrentCell.RowIndex);
            }
        }

        private void toolStripCancel_Click(object sender, EventArgs e)
        {
            multiTabledataGridView.CancelEdit();
            toolStripSave.Enabled = false;
            toolStripCancel.Enabled = false;
        }

        private void toolStripRefresh_Click(object sender, EventArgs e)
        {
            toolStrip1.Enabled = false;
            LoadDataIntoGrid();
            toolStrip1.Enabled = true;
        }
    }
}