httpHelper example code to get value from URL

/// <summary>
        /// 从URL获取值(字符串)
        /// </summary>
        public static string GetValueFromUrl(string key)
        {
            string keyvalue = HttpContext.Current.Request.QueryString[key];
            if (keyvalue != null)
            {
                keyvalue = KillBadString(keyvalue);

                return keyvalue;
            }
            return "";
        }
        /// <summary>
        /// 从URL获取值(整型)
        /// </summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public static int GetIntValueFromUrl(string key)
        {
            string keyvalue = HttpContext.Current.Request.QueryString[key];
            int result = 0;

            if (int.TryParse(keyvalue, out result))
            {
                return result;
            }

            return result;
        }

        /// <summary>
        /// 过滤SQL敏感字符
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string KillBadString(string str)
        {
            if (str == null || str.Length == 0)
            {
                return "";
            }
            str = System.Text.RegularExpressions.Regex.Replace(str, "&#39;", "&#39;&#39;");
            return str;
        }