获取文件的MD5码（C#）

using System;using System.IO;using System.Security.Cryptography;using System.Text;namespace Test
{    public class md5Code    {        /// <summary>        /// 获取文件的MD5码        /// </summary>        /// <param name="fileName">传入的文件名（含路径及后缀名）</param>        /// <returns></returns>        public string GetMD5HashFromFile(string fileName)        {            try            {                FileStream file = new FileStream(fileName, System.IO.FileMode.Open);                MD5 md5 = new MD5CryptoServicePRovider();                byte[] retVal = md5.ComputeHash(file);                file.Close();                StringBuilder sb = new StringBuilder();                for (int i = 0; i < retVal.Length; i++)                {                    sb.Append(retVal[i].ToString("x2"));                }                return sb.ToString();            }            catch (Exception ex)            {                throw new Exception("GetMD5HashFromFile() fail,error:" + ex.Message);            }        }    }}