/*______________________________________________________________
 *                G E T T I N G   T O   K N O W   L I N Q   Step 3
 * 
 *                                    C# VERSION
 *                                     Ron Kessler
 *                                        2/5/09
 * 
 * 
 * _____________________________________________________________
 */

// This time lets us choose a category from a drop down listbox.
//I show how to use an Alias in the Linq Query and how to format data as currency.

//Look at the properties for the grid. I right-aligned the columns and used a Verdana Font.



// BE SURE TO SET THIS AS THE STARTUP PAGE IN THE SOLUTION EXPLORER

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Step3 : System.Web.UI.Page
{

    //---first create a new reference to our datacontext object

    AdventureworksDataContext dc = new AdventureworksDataContext();

    protected void Page_Load(object sender, EventArgs e)
    {


        if (!Page.IsPostBack)
        {
            //---create the LINQ SQL to fill the list box

            var categories = from c in dc.ProductCategories
                                    select c;

            ddlCategory.DataSource = categories;
            ddlCategory.DataValueField = "ProductCategoryID";    //data table column name
            ddlCategory.DataTextField = "Name";                    //data table column name


            //---now link up the grid to display our data


            ddlCategory.DataBind();      //make it so! 
        }



    }

    protected void ddlCategory_SelectedIndexChanged(object sender, EventArgs e)
    {
        //Product_Number below is like a SQL alias
        var products = from p in dc.Products
                       where p.ProductCategoryID == int.Parse(ddlCategory.SelectedValue)
                       select new  { Product_Number = p.ProductNumber,
                           p.Name, p.Color, 
                           Price = String.Format("{0:n2}", p.ListPrice)};      //format as currency 2 dec. places & Price as Alias
                        

        GridView1.DataSource = products;
        DataBind();

    }


}