url重写实现任意二级域名或多级域名（修正参数中断问题）

简要回顾：
     修改微软的URLRewrite能够对URL进行重写，这里要求对域名进行重写，实现http://1234.abc.com/ 到http://www.abc.com/show.aspx?id=1234的重写。
步骤：1、你的域名 http://www.abc.com/ 是泛解析的，并在IIS里添加了主机头为空的映射；
2、修改微软的URLRewriter,要改两个地方
      （1）.BaseModuleRewriter.cs
protected virtual void BaseModuleRewriter_AuthorizeRequest(object sender, EventArgs e)
        {
             HttpApplication app = (HttpApplication) sender;
             Rewrite(app.Request.Url.AbsoluteUri, app);
         }
就是将 app.Request.Path 替换成了 app.Request.Url.AbsoluteUri

       （2）.ModuleRewriter.cs

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 = "^" + 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))
                {
                    // match found - do any replacement needed
                    string sendToUrl = RewriterUtils.ResolveUrl(app.Context.Request.ApplicationPath, re.Replace(requestedPath, rules[i].SendTo));
 
                    // log rewriting information to the Trace object
                     app.Context.Trace.Write("ModuleRewriter", "Rewriting URL to " + sendToUrl);
 
                    // Rewrite the URL
                     RewriterUtils.RewriteUrl(app.Context, sendToUrl);
                    break;        // exit the for loop
                 }
             }
将string lookFor = "^" + RewriterUtils.ResolveUrl(app.Context.Request.ApplicationPath, rules[i].LookFor) + "$";
改成了 string lookFor = "^" + rules[i].LookFor + "$";

     完成这2处改动之后重新编译项目，将生成的dll复制到你项目的bin目录下。

3、再就是写web.config里的重写正则了

<RewriterRule>
            <LookFor>http://(\d+)\.abc\.com</LookFor>
            <SendTo>/show.aspx?id=$1</SendTo>
        </RewriterRule>
注意：
问题出来了，很多人做了，实现了域名的跳转，但很多人都是转到了首页，这里不是lookfor / to /default.aspx 的问题，我自己也遇到了这样的问题，你需要在重写规则里加一个“/”在lookFor的结尾什么的规则改后成了：
<RewriterRule>
            <LookFor>http://(\d+)\.abc\.com/</LookFor>
            <SendTo>/show.aspx?id=$1</SendTo>
        </RewriterRule>
再一个问题，就是修改后的重写对参数的不友好,重写后的URL如果带有参数如http://www.abc.com/news.html?id=1000,重写就返回404.下面提供重写后参数中断的解决方法：
方法一：
         修改重写规则，让正则表达式接受参数：
<RewriterRule>
            <LookFor>http://(\d+)\.abc\.com/news.html(.{0,})</LookFor>
            <SendTo>/show.aspx?id=$1</SendTo>
        </RewriterRule>然后你的各种参数都可以匹配到NEWS页面，比如ID，分页等，在页面里就可以正常使用参数了。

方法二：
     修改上面的BaseModuleRewriter.cs
protected virtual void BaseModuleRewriter_AuthorizeRequest(object sender, EventArgs e)
        {
             HttpApplication app = (HttpApplication) sender;
              string path = app.Request.Url.AbsoluteUri;
              if(path.Contains("?"))
                 {
                     path = path.Split('?')[0];
                 }
              Rewrite(path, app);         }
把带“？”的绝对URL拆开，只去匹配不带参数的URL。

方法三：
     修改ModuleRewriter.cs
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 = "^" + rules[i].LookFor + "(.{0,})$";
 
                // 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))
                {
                    // match found - do any replacement needed
                    string sendToUrl = RewriterUtils.ResolveUrl(app.Context.Request.ApplicationPath, re.Replace(requestedPath, rules[i].SendTo));
 
                    // log rewriting information to the Trace object
                     app.Context.Trace.Write("ModuleRewriter", "Rewriting URL to " + sendToUrl);
 
                    // Rewrite the URL
                     RewriterUtils.RewriteUrl(app.Context, sendToUrl);
                    break;        // exit the for loop
                 }
             }
将string lookFor = "^" + rules[i].LookFor + "$"; 改成string lookFor = "^" + rules[i].LookFor + "(.{0,})$";

结束
-------------------------------
我的项目网站：http://www.at0086.com/ 有不少二级域名比如：hotel.at0086.com ，重写的例子有www.at0086.com/TsinghuaU/

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/zj1103/archive/2008/08/30/2851381.aspx