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;
using System.Text; // Wymagane przez StringBuilder.

public partial class _Default : System.Web.UI.Page
{
   protected void Page_Load(object sender, EventArgs e)
   {
   }

   protected void rbl_SelectedIndexChanged(object sender, EventArgs e)
   {
      if (rbl.SelectedIndex != -1)
      {
         string[] Books = new string[3];

         Session["cattext"] = rbl.SelectedItem.Text;
         Session["catcode"] = rbl.SelectedItem.Value;

         switch (rbl.SelectedItem.Value)
         {
            case "n":
               Books[0] = "Programming C#";
               Books[1] = "Programming ASP.NET";
               Books[2] = "C# Essentials";
               break;
            case "d":
               Books[0] = "Oracle & Open Source";
               Books[1] = "SQL in a Nutshell";
               Books[2] = "Transact-SQL Programming";
               break;
            case "h":
               Books[0] = "PC Hardware in a Nutshell";
               Books[1] = "Dictionary of PC Hardware and Data Communications Terms";
               Books[2] = "Linux Device Drivers";
               break;
         }
         Session["books"] = Books;
      }
   }

   protected void btn_Click(object sender, EventArgs e)
   {
      if (rbl.SelectedIndex == -1)
      {
         lblMessage.Text = "Naley zaznaczy kategori ksiki.";
      }
      else
      {
         StringBuilder sb = new StringBuilder();
         sb.Append("Zostaa wybrana kategoria ");
         sb.Append((string)Session["cattext"]);
         sb.Append(" with code \"");
         sb.Append((string)Session["catcode"]);
         sb.Append("\".");

         lblMessage.Text = sb.ToString();

         ddl.Visible = true;

         string[] CatBooks = (string[])Session["books"];

         // Wypenienie kontrolki DropDownList.
         int i;
         ddl.Items.Clear();
         for (i = 0; i < CatBooks.GetLength(0); i++)
         {
            ddl.Items.Add(new ListItem(CatBooks[i]));
         }
      }
   }
}
