首先提个aspx的小技巧，vs里面默认的aspx页面是设计和编程分开的，两者分别在.aspx和.cs页面，而它们关联的前提是在.aspx页面里添加了下面代码：

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="web._Default" %>

如果要把代码直接写到aspx页面里，则头部代码改为

<%@ Page Language="C#" AutoEventWireup="true" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Net" %>

言归正传，下面整理aspx采集alexa值的方法，这里有个获取页面源码的小函数GetHtml

public HttpWebRequest request;
public HttpWebResponse response;
public string GetHtml(string url, string encode)
{
string str = null;
request = (HttpWebRequest)WebRequest.Create(url);
request.Method = “Get”;
request.ContentType = “application/x-www-form-urlencoded”;
response = (HttpWebResponse)request.GetResponse();
if (response.StatusCode == HttpStatusCode.OK)
{
StreamReader sr = null;
switch (encode)
{
case “UTF-8″:
sr = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
break;
case “GBK”:
sr = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(“GBK”));
break;
case “GB2312″:
sr = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(“GB2312″));
break;
default:
sr = new StreamReader(response.GetResponseStream(), Encoding.Default);
break;
}
str = sr.ReadToEnd();
}
return str;
}

调用这个函数

protected void Page_Load(object sender, EventArgs e)
{
string url= Request.QueryString["url"];
string html=GetHtml(“http://www.alexa.com/siteinfo/”+url,”UTF-8″);
string regex = @”style=”"margin-bottom:-2px;”"/> (?[^<]*)“;//用正则过滤得到需要的内容alexa值
MatchCollection mc = Regex.Matches(html, regex, RegexOptions.IgnoreCase);//获取正则匹配的内容
string alexa = null;
foreach (Match m in mc)
{
alexa = m.Groups["alexa"].Value.ToString();
}
divshow.InnerHtml = alexa;//把alexa值赋值给divshow
}

页面里加个显示控件

最终效果浏览：http://localhost/alexa.aspx?url=baizoo.cn