Редактирование данных с привязкой данных.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
 
namespace Chapter_13
{
    public partial class DetailForm : Form
    {
        public DetailForm()
        {
            InitializeComponent();
        }
 
        BindingSource orderDetailsBindingSource, productsBindingSource;
        NorthwindDataSet.ProductsDataTable productsTable;
        DataRowView orderDetailDataRowView;
 
        public void EditDetail(BindingSource OrderDetailsBindingSource,
                               BindingSource ProductsBindingSource)
        {
            this.productsBindingSource = ProductsBindingSource;
            this.productsTable = (NorthwindDataSet.ProductsDataTable)((DataView)this.productsBindingSource.List).Table;
 
            this.orderDetailsBindingSource = OrderDetailsBindingSource;
            this.orderDetailDataRowView = (DataRowView)this.orderDetailsBindingSource.Current;
            if (this.orderDetailDataRowView.IsNew)
            {
                NorthwindDataSet.ProductsRow product = this.productsTable[0];
                orderDetailDataRowView["Quantity"] = 1;
                orderDetailDataRowView["ProductID"] = product.ProductID;
                orderDetailDataRowView["UnitPrice"] = product.UnitPrice;
            }
 
            this.productIDComboBox.DisplayMember = "ProductName";
            this.productIDComboBox.ValueMember = "ProductID";
            this.productIDComboBox.DataSource = this.productsBindingSource;
            this.productIDComboBox.DataBindings.Add("SelectedValue", this.orderDetailsBindingSource, "ProductID");
            this.productIDComboBox.SelectionChangeCommitted += new EventHandler(productIDComboBox_SelectionChangeCommitted);
 
            this.unitPriceTextBox.DataBindings.Add("Text", this.orderDetailsBindingSource, "UnitPrice", true, DataSourceUpdateMode.OnValidation, "<Null>", "C2");
 
            this.quantityTextBox.DataBindings.Add("Text", this.orderDetailsBindingSource, "Quantity", true, DataSourceUpdateMode.OnValidation, "<Null>", "");
            this.quantityTextBox.TextChanged += new EventHandler(quantityTextBox_TextChanged);
 
            this.itemTotalTextBox.DataBindings.Add("Text", this.orderDetailsBindingSource, "ItemTotal", true, DataSourceUpdateMode.OnValidation, "", "C2");
 
            if (this.orderDetailDataRowView.IsNew)
            {
                this.itemTotalTextBox.Text = this.unitPriceTextBox.Text;
            }
 
            if (this.ShowDialog() == DialogResult.OK)
                this.orderDetailsBindingSource.EndEdit();
            else
                this.orderDetailsBindingSource.CancelEdit();
        }
 
        void quantityTextBox_TextChanged(object sender, EventArgs e)
        {
            this.UpdateItemTotal();
        }
 
        void UpdateItemTotal()
        {
            int quantity;
            decimal unitPrice;
            if (int.TryParse(this.quantityTextBox.Text, out quantity) &&
                decimal.TryParse(this.unitPriceTextBox.Text, System.Globalization.NumberStyles.Currency, null, out unitPrice))
                this.itemTotalTextBox.Text = (unitPrice * quantity).ToString("C");
        }
 
        void productIDComboBox_SelectionChangeCommitted(object sender, EventArgs e)
        {
            if (this.productIDComboBox.SelectedIndex != -1)
            {
                int productID = (int)this.productIDComboBox.SelectedValue;
                NorthwindDataSet.ProductsRow productRow = this.productsTable.FindByProductID(productID);
                this.unitPriceTextBox.Text = productRow.UnitPrice.ToString("C");
 
                this.UpdateItemTotal();
            }
        }
    }
}

private void orderDetailsEditButton_Click(object sender, EventArgs e)
        {
            using (DetailForm detailForm = new DetailForm())
            {
                detailForm.EditDetail(this.order_DetailsBindingSource, this.productsBindingSource);
            }
        }
 
        private void orderDetailsAddButton_Click(object sender, EventArgs e)
        {
            DataRowView newOrderDetail = (DataRowView)this.order_DetailsBindingSource.AddNew();
 
            using (DetailForm detailForm = new DetailForm())
            {
                detailForm.EditDetail(this.order_DetailsBindingSource, this.productsBindingSource);
            }
        }