则通过 <customErrors> 节可以配置相应的处理步骤。具体说来，
开发人员通过该节可以配置
要显示的 html 错误页
以代替错误堆栈跟踪。
<customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
<error statusCode="403" redirect="NoAccess.htm" />
<error statusCode="404" redirect="FileNotFound.htm" />
</customErrors>
-->
<globalization requestEncoding="utf-8" responseEncoding="utf-8"/>
</system.web>
</configuration>
两个关键的类是ModuleRewriter和RewriterFactoryHandler
ModuleRewriter类用于Url重定向，代码如下：
ModuleRewriter
using System;
using System.Text.RegularExpressions;
using System.Configuration;
using URLRewriter.Config;
using System.Data;
using System.Web;
using System.Web.UI;
namespace URLRewriter
{
/**//// <summary>
/// Provides a rewriting HttpModule.
/// </summary>
public class ModuleRewriter : BaseModuleRewriter
{
/**//// <summary>
/// This method is called during the module''s BeginRequest event.
/// </summary>
/// <param name="requestedRawUrl">The RawUrl being requested (includes path and querystring).</param>
/// <param name="app">The HttpApplication instance.</param>
protected override void Rewrite(string requestedPath, System.Web.HttpApplication app)
{
//只对文件后缀为aspx页面有效
if (requestedPath.IndexOf(".aspx") != -1)
{
HttpContext httpContext = app.Context;
// get the configuration rules
RewriterRuleCollection rules = RewriterConfiguration.GetConfig().Rules;
// iterate through each rule
for (int i = 0; i < rules.Count; i++)
{
// get the pattern to look for, and Resolve the Url (convert ~ into the appropriate directory)
string lookFor = "^" + RewriterUtils.ResolveUrl(httpContext.Request.ApplicationPath, rules[i].LookFor) + "$";
// Create a regex (note that IgnoreCase is set)
Regex re = new Regex(lookFor, RegexOptions.IgnoreCase);
// See if a match is found
if (re.IsMatch(requestedPath))
{
//aspx页面重定向到htm页面且http数据传输方式为“GET”
if (rules[i].Type == WebType.Static && app.Context.Request.RequestType == "GET")
{
//静态页面路径
string htmlWeb = RewriterUtils.ResolveUrl(httpContext.Request.Appl
