using System;using System.IO;using System.Security.Cryptography;using System.Text;namespace SendOutRequire{    public class MD5Code    {        /// 
        /// 获取文件的MD5码        /// 
        /// 传入的文件名（含路径及后缀名）        /// 
             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);            }        }    }}

 

出处：http://blog.csdn.net/joyhen/article/details/25107441