asp.net URL重写

各位好，小弟正在学习url重写，在网上看了那些方法好像都不是很全面，而且大多数是一样，不知道各位有做过这方面的没有，发一份我参考一下，谢谢了！

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using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Text.RegularExpressions;

/// <summary>
///URL重写
/// </summary>
public class UrlReWriter:IHttpModule
{
    public UrlReWriter(){}
    public void Dispose()
    {
        throw new NotImplementedException();


       
    }

    public void Init(HttpApplication context)
    {
        context.BeginRequest += new EventHandler(context_BeginRequest);
        context.Error += new EventHandler(context_Error);
    }


    void context_Error(object sender, EventArgs e)
    {
        HttpApplication application = (HttpApplication)sender;
        HttpContext context = application.