Bulk Edit with GridView without xxxDataSource (SqlDataSource, ObjectDataSource, etc.)

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

/// <summary>
/// Summary description for ProductEntity
/// </summary>
public class ProductEntity
{
    private int _productID;
    private string _productName;
    private double _unitPrice;
    private bool _discontinued;
    private DateTime _lastChange;

    public int ProductID
    {
        get
        {
            return _productID;
        }

        set
        {
            _productID = value;
        }
    }

    public string ProductName
    {
        get
        {
            return _productName;
        }

        set
        {
            _productName = value;
        }
    }

    public double UnitPrice
    {
        get
        {
            return _unitPrice;
        }

        set
        {
            _unitPrice = value;
        }
    }

    public bool Discontinued
    {
        get
        {
            return _discontinued;
        }

        set
        {
            _discontinued = value;
        }
    }

    public DateTime LastChange
    {
        get
        {
            return _lastChange;
        }

        set
        {
            _lastChange = value;
        }
    }
}