/// 
    /// 根据网页地址去下载网页，包括从网页中获取自己所需要的内容    /// 
    public class WebWrapper    {        public WebWrapper() { }        public WebWrapper(string link) { Link = link; }        #region Download html        public string Link { get; set; }        public string DownLoadHtml(string link)        {            string htmlString = string.Empty;            try            {                WebRequest webRequest = System.Net.WebRequest.Create(link);                webRequest.Method = "GET";                webRequest.ContentType = "application/x-www-form-urlencoded";                using (StreamReader sr = new StreamReader(webRequest.GetResponse().GetResponseStream()))                {                    htmlString = sr.ReadToEnd();                }            }            catch (Exception ex)            {                throw new ApplicationException(string.Format("Error Downloading CurrencyRate: {0}", ex.Message));            }            return htmlString;        }        public string DownLoadHtml()        {            if (string.IsNullOrEmpty(Link))                throw new ApplicationException("Please input web address");            return DownLoadHtml(Link);        }        #endregion        #region Get matched content        public string GetContent(string html, string regexExpress)        {            Regex re = new Regex(regexExpress);            MatchCollection ms = re.Matches(html);            if (ms == null || ms.Count == 0)                throw new ApplicationException("Can not find matched content");            return ms[0].ToString();        }        public string GetContent(string regexExpress)        {            string html = DownLoadHtml();            return GetContent(html, regexExpress);        }        #endregion        #region Regex Properties        public string BeginConstruction = "(?<=({0}))";        public string EndConstruction = "(?=({0}))";        public string RegexBeginExpression(string begin) { return string.Format(BeginConstruction, begin); }        public string RegexEndExpression(string end) { return string.Format(EndConstruction, end); }        public string RegexAnyExpression { get { return "[.\\s\\S]*?"; } }        #endregion    }