C# Md5Hash的用法及实例

/// <summary>

        /// MD5　32位加密(大写)

        /// </summary>

        /// <param name="str"></param>

        /// <returns></returns>

        static string UserMd5(string str)

        {

            string cl = str;

            string pwd = "";

            MD5 md5 = MD5.Create();//实例化一个md5对像

            // 加密后是一个字节类型的数组，这里要注意编码UTF8/Unicode等的选择　

            byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(cl));

            // 通过使用循环，将字节类型的数组转换为字符串，此字符串是常规字符格式化所得

            for (int i = 0; i < s.Length; i++)

            {

                // 将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母，如果使用大写（X）则格式后的字符是大写字符

                pwd = pwd + s[i].ToString("X");

            }

            return pwd;

        }

        /// <summary>

        /// MD5 16位加密 加密后密码为小写

        /// </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 加密后密码为大写

        /// </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(小写)

        /// </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();

        }