C# Md5Hash的用法及執行個體

/// <summary>        /// MD5　32位加密(大寫)        /// </summary>        /// <param name="str"></param>        /// <returns></returns>        static string UserMd5(string str)        {            string cl = str;            string pwd = "";            MD5 md5 = MD5.Create();//執行個體化一個md5對像            // 加密後是一個位元組類型的數組，這裡要注意編碼UTF8/Unicode等的選擇　            byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(cl));            // 通過使用迴圈，將位元組類型的數群組轉換為字串，此字串是常規字元格式設定化所得            for (int i = 0; i < s.Length; i++)            {                // 將得到的字串使用十六進位類型格式。格式後的字元是小寫字母，如果使用大寫（X）則格式後的字元是大寫字元                 pwd = pwd + s[i].ToString("X");            }            return pwd;        }        /// <summary>        /// MD5 16位加密 加密後密碼為小寫        /// </summary>        /// <param name="ConvertString"></param>        /// <returns></returns>        public static string GetMd5str(string ConvertString)        {            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();            string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8);            t2 = t2.Replace("-", "");            t2 = t2.ToLower();            return t2;        }        /// <summary>        /// MD5 16位加密 加密後密碼為大寫        /// </summary>        /// <param name="ConvertString"></param>        /// <returns></returns>        public static string GetMd5Str(string ConvertString)        {            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();            string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8);            t2 = t2.Replace("-", "");            return t2;        }        /// <summary>        /// MD5加密(小寫)        /// </summary>        /// <param name="input"></param>        /// <returns></returns>        private static string Md5Hash(string input)        {            MD5CryptoServiceProvider md5Hasher = new MD5CryptoServiceProvider();            byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(input));            StringBuilder sBuilder = new StringBuilder();            for (int i = 0; i < data.Length; i++)            {                sBuilder.Append(data[i].ToString("x2"));            }            return sBuilder.ToString();        }