實例一：string result = "";
            string str = "你們好! <User EntryTime='2010-10-7' Email='zhangsan@163.com'>張三</User> 自我介紹。";
            Regex regex = new Regex(@"<User\s*EntryTime='(?<time>[\s\S]*?)'\s+Email='(?<email>[\s\S]*?)'>(?<userName>[\s\S]*?)</User>", RegexOptions.IgnoreCase);
            Match match = regex.Match(str);
            if (match.Success)
            {
                string userName = match.Groups["userName"].Value; //獲取用戶名
                string time = match.Groups["time"].Value; //獲取入職時間
                string email = match.Groups["email"].Value; //獲取郵箱地址
                string strFormat = String.Format("我是：{0}，入職時間：{1}，郵箱：{2}", userName, time, email);
                result = regex.Replace(str, strFormat); //替換內容
                Console.WriteLine(result);
            }
實例二：
            var s = "http://www.baidu.com/articles/2018/3/15/sss.html";
            var reg = new Regex(@"articles/(?<date>\d{4}/\d{1,2}/\d{1,2})/", RegexOptions.IgnoreCase);
            Match _match = reg.Match(s);
            if (_match.Success)
            {
                Console.WriteLine(_match.Groups["date"]);
            }