转:http://www.ninedns.com/asp.net/2007102520726.html
以前用url重写时是用的ms urlrewriter,用了以后发现了很多不足,自定义功能太弱,而且随着重写规则的增加,web.config可能会越来越大,实际上,url重写就是实现IHttpHandler接口.
整个流程分二步走:
1、用一个xml文件来存储重写规则,其中这些规则是一些简单的正则表达式
2、实现IHttpHandler接口
首先看一下xml文件的格式:
<?xml version="1.0" encoding="utf-8" ?>
<root>
<regex>
<!--重写以后的虚拟地址-->
<b><![CDATA[xxx,(?<id>[0-9]+).html$]]></b>
<!--实际地址-->
<a><![CDATA[xxx.aspx?id=${id}]]></a>
</regex>
</root>
相信上面的xml大家都能看懂.
using System;
using System.IO;
using System.Data;
using System.Configuration;
using System.Collections.Generic;
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;
using System.Text.RegularExpressions;
using Microsoft.VisualBasic;
//RegexInfo结构,用来存储从xml文件中读取到的数据
public struct RegexInfo
{
public string _before;
public string _after;
public RegexInfo(string before, string after)
{
_before = before.ToLower();
_after = after.ToLower();
}
}
//ipFilter结构,用来存储被封的IP
public struct ipFilter
{
public string _ip;
public ipFilter(string ip)
{
_ip = ip;
}
}
public class HtmlHttpHandler : IHttpHandler //实现IHttpHandler接口
{
private List<RegexInfo> _regex_list = new List<RegexInfo>();
private List<ipFilter> _ip_filter = new List<ipFilter>();
public HtmlHttpHandler()
{
DataSet ds = new DataSet();
//读取url重写规则文件,并写入RegexInfo结构的实例中
ds.ReadXml(System.Web.HttpContext.Current.Server.MapPath("~/App_Data/Regexs.xml"));
foreach (DataRow r in ds.Tables["regex"].Rows)
_regex_list.Add(new RegexInfo(((string)r["b"]).Trim(), ((string)r["a"]).Trim()));
ds.Reset();
//读取被封的IP列表
ds.ReadXml(System.Web.HttpContext.Current.Server.MapPath("~/App_Data/ipFilter.xml"));
foreach(DataRow r in ds.Tables["IpFilters"].Rows)
_ip_filter.Add(new ipFilter((string)r["ip"]));
}
public void ProcessRequest(HttpContext context)
{
string _ip = context.Request.UserHostAddress; //获取IP
foreach (ipFilter r in _ip_filter)
{
if (_ip == r._ip)
{
context.Response.Write("对不起,您的IP:"+_ip+"已被限制!");
context.Response.End();
}
}
string path = context.Request.Path.ToLower(); //获取当前访问的重写过的虚假URL
foreach (RegexInfo r in _regex_list)
path = Regex.Replace(path, r._before, r._after); //匹配出其真实的URL
context.Server.Execute(path);
}
// Override the IsReusable property.
public bool IsReusable
{
get { return true; }
}
}
OK,IHttpHandler接口就被实现了,下面稍配一下web.config就可以实现URL重写了
在web.config的<system.web></system.web>中加入 :
<httpHandlers>
<add verb="*" path="*.html" type="HtmlHttpHandler"/>
</httpHandlers>
表示后缀名为.html的文件全部交给HtmlhttpHandler类去处理,最后配一下iis就行了。
至于简繁的转换,你可以加到ProcessRequest中,至于如何实现转换见下一页。
ASP.net的RUL重写
有关于URL的重写,本文也只是拿来主意。相继有MS的组件“URLRewriter”和在Global.asax里的“Application_BeginRequest()”编码方式,以及IIS里的ISAPI设置。
娜列下来,实现方法也都很简单。
方法一:MS组件
这里也不用详解了,相关请看:
http://www.microsoft.com/china/msdn/library/webservices/asp.net/URLRewriting.mspx
用法很简单,只需要把组件URLRewriter.dll拷到应用程序的bin目录下,然后在web.config下加入如下代码:
在<configuration></configuration>中加入:
<configSections>
<section name="RewriterConfig" type="URLRewriter.Config.RewriterConfigSerializerSectionHandler, URLRewriter" />
</configSections>
<RewriterConfig>
<Rules>
<RewriterRule>
<LookFor>~/(\d{4})/(\d{2})/Default\.aspx</LookFor>
<SendTo>~/Default.aspx?ID=$1</SendTo>
</RewriterRule>
</Rules>
</RewriterConfig>
然后在<system.web></system.web>中加入:
<httpHandlers>
<add verb="*" path="*.aspx"
type="URLRewriter.RewriterFactoryHandler, URLRewriter" />
</httpHandlers>
最后在地址栏上键入:http://localhost/Test/2004/12/News.aspx
效果出来了。
上面的<LookFor>~/(\d{4})/(\d{2})/News\.aspx</LookFor>这句这正则表达式URL,即被重写的URL,而<SendTo>~/Default.aspx?ID=$1</SendTo>这一句为原始URL地址。其中的$1为第一个正则表达式值(上面例子为:2004),以此类推,第二个即为$2
方法二:Application_BeginRequest()
在应用程序中新建一个XML文件,文件内容为:文件名ReWriter.config
<?xml version="1.0" encoding="utf-8" ?>
<ReWriterUrls>
<rule>
<old>(.*)/News/(\d{4})/Default\.aspx</old>
<new>http://www.cnblogs.com/Default.aspx?id=$2&type=$3</new>
</rule>
</ReWriterUrls>
在Global.asax文件中的Application_BeginRequest(Object sender, EventArgs e)加入代码:
try
{
string path=Server.MapPath("~/ReWriter.config");
XPathDocument myXPathDocument = new XPathDocument(path);
XPathNavigator myXPathNavigator = myXPathDocument.CreateNavigator();
XPathNodeIterator myXPathNodeIterator = myXPathNavigator.Select ("//rule");
System.Text.RegularExpressions.Regex oReg;
string ReWriteUrl;
while (myXPathNodeIterator.MoveNext())
{
//oReg=new Regex(oNode.SelectSingleNode("url/text()").Value);
XPathNavigator nav2 = myXPathNodeIterator.Current.Clone();
string oldString="",newString="";
XPathNodeIterator it2 = nav2.Select("old");
while(it2.MoveNext())
{
oldString = it2.Current.Value;
break;
}
it2 = nav2.Select("new");
while(it2.MoveNext())
{
newString = it2.Current.Value;
break;
}
if(oldString != "" && newString != "")
{
oReg = new System.Text.RegularExpressions.Regex(oldString);
if(oReg.IsMatch(Request.Url.ToString()))
{
ReWriteUrl = oReg.Replace(Request.Url.ToString(),newString);
HttpContext.Current.RewritePath(ReWriteUrl);
break;
}
}
}
}
catch
{
}
最后在地址栏上键入:http://localhost/Test/News/2004/Default.aspx
效果出来了。
http://www.cnblogs.com/HD/archive/2005/06/21/178367.html
http://blog.csdn.net/showmy/archive/2007/11/01/1861400.aspx
MSDN有详细绍
http://msdn.microsoft.com/zh-cn/library/ms972974.aspx