获取天气预报c#

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.IO;
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.RegularExpressions;
using System.Net;
using System.Xml;

ArrayList al = new ArrayList();//存放天气对象
public ArrayList run()
{
WebRequest wr = WebRequest.Create("http://news.sina.com.cn/weather/bj.html");
WebResponse rs = wr.GetResponse();

StreamReader sr = new StreamReader(rs.GetResponseStream(), System.Text.Encoding.GetEncoding("gb2312"));

string htm = sr.ReadToEnd();

Regex regex = new Regex(@"<div class=/SWeather_TP/S>(?<tp>[^<>]+?/s*)</div>|<div class=/SWeather_W/S>(?<w>[^<>]+?/s*)</div>", RegexOptions.IgnoreCase | RegexOptions.Multiline | RegexOptions.Singleline);
MatchCollection m = regex.Matches(htm);

tq t = null;
for (int i = 0; i < m.Count; i++)
{
t = new tq();

t.a = m[i].Groups["tp"].Value;
i++;
t.b = m[i].Groups["w"].Value.Replace("&nbsp;", "");

al.Add(t);

}
return al;
}
}