another gridview question (temporary storage??)

 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.Collections;


using System.Collections.Specialized;


using System.ComponentModel;


using System.IO;


using System.Text;


using System.Text.RegularExpressions;


using System.Web.Caching;


using System.Web.SessionState;


using System.Web.UI.HtmlControls;


using System.Web.Mail;


using System.Net;


using System.Drawing;


using System.Data.SqlClient;


using EntitySpaces.Core;


using EntitySpaces.Interfaces;


using BusinessObjects;





public partial class Product : System.Web.UI.Page


{


    DataSet ds;


    ProductsCollection pc;


    


    protected void Page_Load(object sender, EventArgs e)


    {


        pc = BusinessObjects.Products.getallproducts();


        pc.LowLevelBind();


        


       


    }





    private DataTable createCartDT()


    {


        DataTable dtProducts = new DataTable();


        DataColumn productColumn = new DataColumn();


        


        productColumn.DataType = System.Type.GetType("System.Int32");


        productColumn.ColumnName = "ProductId";


        productColumn.Unique = true;


        dtProducts.Columns.Add(productColumn);





        productColumn = new DataColumn();


        productColumn.DataType = System.Type.GetType("System.String");


        productColumn.ColumnName = "ProductName";


        dtProducts.Columns.Add(productColumn);





        productColumn = new DataColumn();


        productColumn.DataType = System.Type.GetType("System.Double");


        productColumn.ColumnName = "ProductPrice";


        dtProducts.Columns.Add(productColumn);





        productColumn = new DataColumn();


        productColumn.DataType = System.Type.GetType("System.Int32");


        productColumn.ColumnName = "Quantity";


        dtProducts.Columns.Add(productColumn);





        // Make "id" the primary key


        DataColumn[] pkColumns = new DataColumn[1];


        pkColumns[0] = dtProducts.Columns["ProductId"];


        dtProducts.PrimaryKey = pkColumns;





        return dtProducts;


    }








    protected void shopBuy_OnServerClick(object source, EventArgs e)


    {





        int index = ((GridViewRow)((HtmlInputImage)source).Parent.NamingContainer).RowIndex;








        // Fetch the productId using the RowIndex we got from the GridViewRow





        addToCart((Convert.ToInt32(gvProducts.DataKeys[index].Value)));





    }














    protected void addToCart(int Pid)


    {


        DataTable dtCart = getCartDt();


        bool found = false;


        for (int i = 0; i < dtCart.Rows.Count; i++)


        {


            if (Convert.ToInt32(dtCart.Rows[i]["ProductId"]) == Pid)


            {


                dtCart.Rows[i]["Quantity"] = Convert.ToInt32(dtCart.Rows[i]["Quantity"]) + 1;


                found = true;


                break;


            }


        }





        if (!found)


        {


            DataTable dtProduct = getProductDt();


            DataRow drProduct = dtProduct.Rows.Find(Pid);


            DataRow newRow = dtCart.NewRow();


            newRow["ProductId"] = drProduct["ProductId"];


            newRow["ProductName"] = drProduct["ProductName"];


            newRow["ProductPrice"] = drProduct["ProductPrice"];


            newRow["Quantity"] = 1;


            dtCart.Rows.Add(newRow);





        }


        Session["dtCart"] = dtCart;


        updateCart();





    }

















    private void updateCart()


    {


        gvBasket.DataSource = getCartDt();


        gvBasket.DataBind();


        ibClearBasket.Visible = ibBasketQuantities.Visible = ibBasketCheckout.Visible = gvBasket.Rows.Count > 0;


    }

















    private DataTable getCartDt()


    {


        DataTable dtCart = null;


        if (Session["dtCart"] == null)


        {


            dtCart = createCartDT();


        }


        else


        {


            dtCart = (DataTable)Session["dtCart"];





        }


        return dtCart;


    }














    protected DataTable getProductDt()


    {





        return (DataTable)ds.Tables[0];








    }

















    protected void gvCart_RowDataBound(object sender, GridViewRowEventArgs e)


    {


        switch (e.Row.RowType)


        {


            case DataControlRowType.DataRow:





                // Name/Desc


                ((Literal)e.Row.FindControl("litItemName")).Text =
Convert.ToString(((DataRowView)e.Row.DataItem)["ProductName"]);





                // Quantity                           


                string quantity = Convert.ToString(((DataRowView)e.Row.DataItem)["Quantity"]);


                ((HtmlInputText)e.Row.FindControl("itProductQuantity")).Value = quantity;





                // Price                           


                ((Literal)e.Row.FindControl("litPrice")).Text =
String.Format("{0:C2}",
Convert.ToDouble(((DataRowView)e.Row.DataItem)["ProductPrice"]) *
Convert.ToInt32(quantity));


                break;





            case DataControlRowType.Footer:


                DataTable dtShop = getCartDt();





                double total = 0.00;


                for (int i = 0; i < dtShop.Rows.Count; i++)


                {


                    total += Convert.ToInt32(dtShop.Rows[i]["Quantity"]) * Convert.ToDouble(dtShop.Rows[i]["ProductPrice"]);


                }





                ((Literal)e.Row.FindControl("litTotalQuantity")).Text = Convert.ToString(dtShop.Compute("SUM(quantity)", ""));





                ((Literal)e.Row.FindControl("litDeliveryPrice")).Text =
String.Format("{0:C2}", Convert.ToDouble(calcDeliveryCost(total)));





                ((Literal)e.Row.FindControl("litTotalPrice")).Text =
String.Format("{0:C2}", Convert.ToDouble(calcDeliveryCost(total)) +
total);


                break;


        }


    }





    /// 



    /// This is a simple delivery cost calculator.  It works off the basket total and not each item individually.


    /// In a more robust system each item would have its own delivery methods and delivery costs which would


    /// account for its dimensions, weight, particular requirements etc.


    /// 



    private string calcDeliveryCost(double total)


    {


        string deliveryCost = "0.00";





        if (total < 30.00)


        {


            deliveryCost = "4.95";


        }


        else if (total >= 30.00 && total < 70.00)


        {


            deliveryCost = "7.95";


        }


        else if (total >= 70.00 && total < 145.00)


        {


            deliveryCost = "10.95";


        }


        else if (total >= 145.00)


        {


            deliveryCost = "0.00";


        }





        return deliveryCost;


    }





    protected void shopClearCart_OnServerClick(object source, EventArgs e)


    {


        Session.Contents.Remove("dtCart");


        updateCart();


    }


    protected void shopUpdateCartQuantities_OnServerClick(object source, EventArgs e)


    {


        DataTable dtCart = getCartDt();





        /*


         * Go through each row in the basket display and compare it to the basket in the session


         * Compare the quantities and modify the Session basket as required to reflect


         * any changes made by the customer via the quanitites input boxes


         */


        foreach (GridViewRow row in gvCart.Rows)


        {


            int index = row.RowIndex;


            int productId = Convert.ToInt32(gvCart.DataKeys[index].Value);





            // Find the product in the Session Basket


            DataRow drProduct = dtCart.Rows.Find(productId);





            if (drProduct != null)


            {


                // Read the data from the Quantity Text Box


                HtmlInputText itQuant = (HtmlInputText)row.FindControl("itProductQuantity");





                // Try and convert the value to an int


                try


                {


                    int quant = Convert.ToInt32(itQuant.Value);





                    /*


                     * If the value converted to an Int successfully we still need to check 


                     * that its not a minus number, otherwise we might end up owing the customer money!


                     */


                    if (quant > 0)


                    {


                        drProduct["Quantity"] = quant;


                    }


                    else


                    {


                        drProduct.Delete();


                    }


                }


                catch


                {


                    // If we cant convert it to an Int then just leave
it as it was i.e. make no changes                                    


                }


            }


        }





        if (dtCart.Rows.Count > 0)


        {


            // IF we still have items in the basket then update the Session Basket


            Session["dtCart"] = dtCart;


        }


        else


        {


            // ELSE delete the Session Basket


            Session.Contents.Remove("dtCart");


        }





        // Refresh the basket display


        updateCart();


    } 











    protected void gvProducts_PageIndexChanging(Object sender, GridViewPageEventArgs e)


    {


        gvProducts.PageIndex = e.NewPageIndex;


        gvProducts.DataSource = ds;


        gvProducts.DataBind();


    }








    protected void shopCartCheckout_OnServerClick(object source, EventArgs e)


    {


        //put your check out code here


    }





}