正则表达式获取远程网页

[一篮饭特稀原创，转载请注明出处http://www.cnblogs.com/wanghafan/archive/2012/02/09/2344276.html]

--简单例子: 

using System.Text;
using System.Text.RegularExpressions;

string str = "<img>123456789</img>";
string regexStr = @"<img>([^<]*)</img>"; 
Match mc = Regex.Match(str, regexStr, RegexOptions.IgnoreCase);
Response.Write(mc.Groups[1].Value);

--天气例子： 

using System.Text;
using System.Text.RegularExpressions;

string str = GetRequestString("http://www.ntxnw.com.cn/tq.asp?s_type=00", 8000, 1, Encoding.GetEncoding("GB2312"));
string regexStr = XXXXXXXXXXXXXXXXXXXXXX;
Match mc = Regex.Match(str, regexStr, RegexOptions.IgnoreCase);
this.divContent.InnerHtml=mc.Groups[1].Value;
         /// <summary>
/// 获取指定远程网页内容
/// </summary>
/// <param name="strUrl">所要查找的远程网页地址</param>
/// <param name="timeout">超时时长设置，一般设置为8000</param>
/// <param name="enterType">是否输出换行符，0不输出，1输出文本框换行</param>
/// <param name="EnCodeType">编码方式</param>
/// <returns></returns>
/// 也可考虑 static string
        public string GetRequestString(string strUrl, int timeout, int enterType, System.Text.Encoding EnCodeType)
        {
            string strResult;
            try
            {
                HttpWebRequest myReq = (HttpWebRequest)HttpWebRequest.Create(strUrl);
                myReq.Timeout = timeout;
                HttpWebResponse HttpWResp = (HttpWebResponse)myReq.GetResponse();
                Stream myStream = HttpWResp.GetResponseStream();
                StreamReader sr = new StreamReader(myStream, EnCodeType);
                StringBuilder strBuilder = new StringBuilder();
                while (-1 != sr.Peek())
                {
                    strBuilder.Append(sr.ReadLine());
                    if (enterType == 1)
                    {
                        strBuilder.Append("\r\n");
                    }
                }
                strResult = strBuilder.ToString();
            }
            catch (Exception err)
            {
                strResult = "请求错误：" + err.Message;
            }
            return strResult;
        }