MD5加密、时间戳转换、base64算法加密、解密

        #region MD5加密
        /// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string MD5(string str)
        {
            return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(str, "MD5");
        }
        #endregion

        #region 时间转换
        //时间转换成时间戳
        public static int ConvertDateTimeInt(System.DateTime time)
        {
            System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1));
            return (int)(time - startTime).TotalSeconds;
        }

        //时间字符串转换成时间戳
        public static int ConvertStringDateTimeInt(string timeStr)
        {
            if (string.IsNullOrEmpty(timeStr) || timeStr.Trim() == "0") return 0;
            DateTime time = DateTime.ParseExact(timeStr, "yyyyMMddHHmmss", System.Globalization.CultureInfo.InstalledUICulture);
            DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1));
            return (int)(time - startTime).TotalSeconds;
        }
        // 时间戳转为C#格式时间
        public static DateTime StampToDateTime(string timeStamp)
        {
            DateTime dateTimeStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1));
            long lTime = long.Parse(timeStamp + "0000000");
            TimeSpan toNow = new TimeSpan(lTime);
            return dateTimeStart.Add(toNow);
        }
        #endregion

　　　　#region 将字符串使用base64算法加密
        /// <summary>
        /// 将字符串使用base64算法加密
        /// </summary>
        /// <param name="SourceString">待加密的字符串</param>
        /// <param name="Ens">System.Text.Encoding 对象，如创建中文编码集对象：
        /// System.Text.Encoding.GetEncoding("gb2312")</param>
        /// <returns>编码后的文本字符串</returns>
        public static string EncodingString(string SourceString, System.Text.Encoding Ens)
        {
            return Convert.ToBase64String(Ens.GetBytes(SourceString));
        }
        #endregion

        #region 从base64编码的字符串中还原字符串，支持中文
        /// <summary>
        /// 从base64编码的字符串中还原字符串，支持中文
        /// </summary>
        /// <param name="Base64String">Base64加密后的字符串</param>
        /// <param name="Ens">System.Text.Encoding对象，如创建中文编码集对象：
        /// System.Text.Encoding.Default</param>
        /// <returns>还原后的文本字符串</returns>
        public static string DecodingString(string Base64String, System.Text.Encoding Ens)
        {
            return Ens.GetString((Convert.FromBase64String(Base64String)));
        }
        #endregion