很多时候我们需要链接转向(Url Rewriting)，例如二级域名转向、文章访问链接等场合。
让我们看两个例子：
1 你现在看到的当前作者的博客园的域名：
http://jx270.cnblogs.com/ 实际上是 http://www.cnblogs.com/jx270 的一种链接重写(Url Rewriting)。
2 codeproject上的文章，我们获取的地址都是以文章主要关键字做的网页名称：
http://www.codeproject.com/cs/webservices/wsdlparser.asp 
个人觉得实际的文章链接可能是如下格式（纯属猜想）
http://www.codeproject.com/news.asp?id=123456  
那么如何在Asp.net2.0中如何实现链接重写呢？
可以采用UrlRewritingNet.UrlRewriter.dll来轻松实现
UrlRewritingNet.UrlRewriter.dll 可从其官方网站下载：http://www.urlrewriting.net
我们要做的就是进行Web.Config文件的设置

1 <configSections>间添加：
  <configSections>
  <section name="urlrewritingnet" restartOnExternalChanges="true" requirePermission="false" type="UrlRewritingNet.Configuration.UrlRewriteSection, UrlRewritingNet.UrlRewriter"/>
</configSections>

3 添加链接重写的设置
<urlrewritingnet rewriteOnlyVirtualUrls="true" contextItemsPrefix="QueryString" defaultPage="default.aspx" defaultProvider="RegEx" xmlns="http://www.urlrewriting.net/schemas/config/2006/07">
  <rewrites>
   <add name="Rewrite1" virtualUrl="^http\://(.*)/UrlRewritingTest/test.aspx" rewriteUrlParameter="ExcludeFromClientQueryString" destinationUrl="~/default.aspx" rewrite="Domain" ignoreCase="true"/>
   <add name="Rewrite2" virtualUrl="^http\://(.*)/UrlRewritingTest/test1.aspx" rewriteUrlParameter="ExcludeFromClientQueryString" destinationUrl="~/info.aspx?year=2007&amp;month=3&amp;day=9" rewrite="Domain" ignoreCase="true"/>
  </rewrites>
</urlrewritingnet>

完整的一个Web.Config文件

<?xml version="1.0"?>
<configuration>
    <configSections>
        <section name="urlrewritingnet" restartOnExternalChanges="true" requirePermission="false" type="UrlRewritingNet.Configuration.UrlRewriteSection, UrlRewritingNet.UrlRewriter"/>
    </configSections>
    <urlrewritingnet rewriteOnlyVirtualUrls="true" contextItemsPrefix="QueryString" defaultPage="default.aspx" defaultProvider="RegEx" xmlns="http://www.urlrewriting.net/schemas/config/2006/07">
        <rewrites>
            <add name="Rewrite1" virtualUrl="^http\://(.*)/UrlRewritingTest/test.aspx" rewriteUrlParameter="ExcludeFromClientQueryString" destinationUrl="~/default.aspx" rewrite="Domain" ignoreCase="true"/>
            <add name="Rewrite2" virtualUrl="^http\://(.*)/UrlRewritingTest/test1.aspx" rewriteUrlParameter="ExcludeFromClientQueryString" destinationUrl="~/info.aspx?year=2007&amp;month=3&amp;day=9" rewrite="Domain" ignoreCase="true"/>
            <add name="Rewrite3" virtualUrl="^http\://(.*)/UrlRewritingTest/test(\d{4})(\d{2})(\d{2}).aspx" rewriteUrlParameter="ExcludeFromClientQueryString" destinationUrl="~/info.aspx?year=$2&amp;month=$3&amp;day=$4" rewrite="Domain" ignoreCase="true"/>
            <add name="Rewrite4" virtualUrl="^http\://(.*)/UrlRewritingTest/(\d{4})/(\d{2})/(\d{2})/info.aspx" rewriteUrlParameter="ExcludeFromClientQueryString" destinationUrl="~/info.aspx?year=$2&amp;month=$3&amp;day=$4" rewrite="Domain" ignoreCase="true"/>
      <add name="Rewrite5" virtualUrl="^http\://(.*)/UrlRewritingTest/stock(\d{6}).aspx" rewriteUrlParameter="ExcludeFromClientQueryString" destinationUrl="~/stockinfo.aspx?code=$2" rewrite="Domain" ignoreCase="true"/>
        </rewrites>
    </urlrewritingnet>
    <appSettings/>
    <system.web>
        <httpModules>
            <add name="UrlRewriteModule" type="UrlRewritingNet.Web.UrlRewriteModule, UrlRewritingNet.UrlRewriter"/>
        </httpModules>
        <compilation debug="true"/>
  </system.web>
</configuration>

示例程序
我们做了一个按查询字符串的输入显示对应日期的页面info.aspx

    protected void Page_Load(object sender, EventArgs e)
    {
        string strYear = Request.QueryString["year"].ToString();
        string strMonth = Request.QueryString["month"].ToString();
        string strDay = Request.QueryString["day"].ToString();
        Response.Write(string.Format("你输入的日期是{0}年{1}月{2}日",strYear,strMonth,strDay));
    }

常规访问方式：http://localhost/UrlRewritingTest/info.aspx?year=2007&month=03&day=08

页面重写方式1：http://localhost/UrlRewritingTest/test20070308.aspx

页面重写方式2：http://localhost/UrlRewritingTest/2007/03/08/info.aspx

大家可以看到实际的访问效果是一致的。

示例文件中还有一个股票信息查看的例子：
http://localhost/UrlRewritingTest/stock600616.aspx = http://localhost/UrlRewritingTest/stockinfo.aspx?code=600616

示例程序下载：/Files/heekui/UrlRewritingTest.rar