Virtuellt RSS-flöde med .NET

<%@ Page Language="C#" Strict="False" Debug="True" Inherits="_Rss" CodeFile="Rss.aspx.cs" %>

using System;
using System.Data;
using System.Data.OleDb;
using System.Configuration;
using System.Text;
using System.Web;
using System.IO;
using System.Xml;

public partial class _Rss : System.Web.UI.Page
{
static string strConn = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
static string strRootUrl = "http://codeodyssey.se";

protected void Page_Load(object sender, EventArgs e)
{
Response.ContentType = "text/xml";
Response.ContentEncoding = Encoding.UTF8;
Response.Write(GetRssString());
}

//Kollar om det redan finns en sträng i cache, annars skapas en ny
protected string GetRssString()
{
string cacheName = "rss-feed";

//Hämta chachad data om det finns
if (Cache[cacheName] != null)
{
return Convert.ToString(Cache[cacheName]);
}
else
{
string newlyGeneratedRss = GenerateRss();
Cache.Insert(cacheName, newlyGeneratedRss, null, DateTime.Now.AddMinutes(20), TimeSpan.Zero);
return Convert.ToString(newlyGeneratedRss);
}
}

//Funktion som skapar en textSträng som innehåller rss-feed
protected string GenerateRss()
{
StringWriter sw = new StringWriter();
try
{

XmlTextWriter xtw = new XmlTextWriter(sw);//,System.Text.Encoding.GetEncoding("UTF-8")
xtw.Formatting = Formatting.Indented;
xtw.WriteStartDocument();

//skriv ut <rss version="2.0">
xtw.WriteStartElement("rss");
xtw.WriteAttributeString("version","2.0");

//skriv ut <channel>
xtw.WriteStartElement("channel");

//skriv ut element som tillhör <channel>
xtw.WriteElementString("title","Codeodyssey.se");
xtw.WriteElementString("link","http://www.codeodyssey.se/");
xtw.WriteElementString("description","Code Odyssey - gräver djupt i kodträsket");
xtw.WriteElementString("language","sv-SE");
xtw.WriteElementString("copyright","Copyright (c) 2004-2007 Code Odyssey");

OleDbConnection conn = new OleDbConnection (strConn);
bool boolPermission = false;
OleDbDataReader objDataReader=null;
try
{
string strSQL = "SELECT TOP 10 * FROM News WHERE Published=true ORDER BY PublishDate DESC";

conn.Open();

OleDbCommand objCommand = new OleDbCommand(strSQL, conn);
objDataReader = objCommand.ExecuteReader();
while (objDataReader.Read() == true)
{
int Id = Convert.ToInt32(objDataReader["Id"]);
string Title = Convert.ToString(objDataReader["Title"]);
string Body= Convert.ToString(objDataReader["Body"]);
//Se till att datum följer RFC-822 standard
string PublishDate = Convert.ToString( ((DateTime)objDataReader["PublishDate "]).ToString("r"));


//skriv ut <item> och dess innehåll
xtw.WriteStartElement("item");
xtw.WriteElementString("title",Title);
xtw.WriteElementString("link", strRootUrl.ToLower() + "/news.aspx?id=" + Id);
xtw.WriteElementString("guid", strRootUrl.ToLower() + "/news.aspx?id=" + Id);
xtw.WriteElementString("description",Body);
xtw.WriteElementString("pubDate",PublishDate);
xtw.WriteEndElement();
}
objCommand.Dispose();
objCommand = null;
}
catch (Exception objException)
{
Trace.Warn("GenerateRss() Fel!",objException.Message);
}
finally
{
if(objDataReader!=null)
{
objDataReader.Close();
objDataReader = null;
}
if(conn!=null)
{
conn.Close();
conn = null;
}
}

//skriv ut </channel>
xtw.WriteEndElement();

//skriv ut </rss>
xtw.WriteEndElement();

//Stäng xml skrivaren
xtw.Close();
}
catch (Exception objException)
{
Trace.Warn("GenerateRss() Fel!",objException.Message);
}
return sw.ToString();
}

}