asp.net automatically adds parameters to the Url address through HttpModule

However, mobile phones and the client does not support Session and Cookie by value, other methods for page assignment to pass values seem to be too much trouble, but also not easy to maintain, easy to lose an error, so the thought of using HttpModule to assign cid parameters on Url address, let url cid parameters automatically pass it on each page, need use cid just by Requet "cid" access, so you don't have to worry about the value and.
The following is the configuration method and the source code.

1) add the following nodes in the web.config configuration file

 
<httpModules> 
<add name="HttpModule" type="ThreeHegemony.Utility.AutoAddCid"/> 
</httpModules> 

2) url is passed by inheriting IHttpModule.

code

 
using System; 
using System.Text; 
using System.Web; 
using System.IO; 
using System.Text.RegularExpressions; 
namespace ThreeHegemony.Utility 
{ 
/// <summary> 
/// Auther: Jess.zou 
/// Create data: 2009-08-06 
/// Description:  This class ACTS on Url Add the address automatically (cid) 
/// </summary> 
public class AutoAddCid : System.Web.IHttpModule 
{ 
public void Init(HttpApplication context) 
{ 
context.PostRequestHandlerExecute += new EventHandler(this.OnPreSendRequestContent); 
} 
protected void OnPreSendRequestContent(Object sender, EventArgs e) 
{ 
System.Web.HttpApplication myContext = (System.Web.HttpApplication)sender; 
myContext.Response.Filter = new AppendSIDFilter(myContext.Response.Filter); 
} 
private void ReUrl_BeginRequest(object sender, EventArgs e) 
{ 
string cid = ""; 
string url = ""; 
HttpContext context = ((HttpApplication)sender).Context; 
if (string.IsNullOrEmpty(context.Request.QueryString["cid"])) 
{ 
if (context.Request.QueryString.Count == 0) 
{ 
url = string.Format("{0}?cid={1}", context.Request.RawUrl, cid); 
} 
else 
{ 
url = string.Format("{0}&cid={1}", context.Request.RawUrl, cid); 
} 
} 
context.RewritePath(url); 
} 
public void Dispose() { } 
public class AppendSIDFilter : Stream 
{ 
private Stream Sink { get; set; } 
private long _position; 
private System.Text.StringBuilder oOutput = new StringBuilder(); 
public AppendSIDFilter(Stream sink) 
{ 
Sink = sink; 
} 
public override bool CanRead 
{ 
get { return true; } 
} 
public override bool CanSeek 
{ 
get { return true; } 
} 
public override bool CanWrite 
{ 
get { return true; } 
} 
public override long Length 
{ 
get { return 0; } 
} 
public override long Position 
{ 
get { return _position; } 
set { _position = value; } 
} 
public override long Seek(long offset, System.IO.SeekOrigin direction) 
{ 
return Sink.Seek(offset, direction); 
} 
public override void SetLength(long length) 
{ 
Sink.SetLength(length); 
} 
public override void Close() 
{ 
Sink.Close(); 
} 
public override void Flush() 
{ 
Sink.Flush(); 
} 
public override int Read(byte[] buffer, int offset, int count) 
{ 
return Sink.Read(buffer, offset, count); 
} 
public override void Write(byte[] buffer, int offset, int count) 
{ 
if (string.IsNullOrEmpty(HttpContext.Current.Request["cid"])) 
{ 
Sink.Write(buffer, 0, buffer.Length); 
return; 
} 
string content = System.Text.UTF8Encoding.UTF8.GetString(buffer, offset, count); 
Regex regex = new Regex(RegexResource.HREF, RegexOptions.IgnoreCase); 
Regex action_regex = new Regex(RegexResource.ACTION, RegexOptions.IgnoreCase); 
if (regex.IsMatch(content)) 
{ 
content = Regex.Replace(content, RegexResource.HREF, new MatchEvaluator(ReplaceSID), RegexOptions.Compiled | RegexOptions.IgnoreCase); 
} 
if (action_regex.IsMatch(content)) 
{ 
content = Regex.Replace(content, RegexResource.ACTION, new MatchEvaluator(ReplaceSID), RegexOptions.Compiled | RegexOptions.IgnoreCase); 
} 
byte[] data = System.Text.UTF8Encoding.UTF8.GetBytes(content); 
Sink.Write(data, 0, data.Length); 
} 
public static string ReplaceSID(Match match) 
{ 
if (match.Value.IndexOf("cid=") != -1) 
{ 
return match.Value; 
} 
string result; 
if (match.Value.IndexOf('?') == -1) 
{ 
result = match.Value.Insert(match.Value.Length - 1, "?cid=" + HttpContext.Current.Request["cid"]); 
} 
else 
{ 
result = match.Value.Insert(match.Value.Length - 1, "&cid=" + HttpContext.Current.Request["cid"]); 
} 
return result; 
} 
} 
} 
}