可用于对比文件是否相同

 1 /// <summary> 2         /// 获取文件MD5值 3         /// </summary> 4         /// <param name="fileName">文件绝对路径</param> 5         /// <returns>MD5值</returns> 6         public static string GetMD5HashFromFile(string fileName) 7         { 8             try 9             {10                 FileStream file = new FileStream(fileName, FileMode.Open);11                 System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();12                 byte[] retVal = md5.ComputeHash(file);13                 file.Close();14 15                 StringBuilder sb = new StringBuilder();16                 for (int i = 0; i < retVal.Length; i++)17                 {18                     sb.Append(retVal[i].ToString("x2"));19                 }20                 return sb.ToString();21             }22             catch (Exception ex)23             {24                 throw new Exception("GetMD5HashFromFile() fail,error:" + ex.Message);25             }26         }