计算文件MD5值

public static string GetMd5Hash(string pathName)          {              string strResult = "";              string strHashData = "";              byte[] arrbytHashValue;                System.IO.FileStream oFileStream = null;                System.Security.Cryptography.MD5CryptoServiceProvider oMD5Hasher = new System.Security.Cryptography.MD5CryptoServiceProvider();                try              {                  oFileStream = new System.IO.FileStream(pathName.Replace("\"", ""), System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.ReadWrite);                    arrbytHashValue = oMD5Hasher.ComputeHash(oFileStream); //计算指定Stream 对象的哈希值                    oFileStream.Close();                    //由以连字符分隔的十六进制对构成的String，其中每一对表示value 中对应的元素；例如“F-2C-4A”                    strHashData = System.BitConverter.ToString(arrbytHashValue);                    //替换-                  strHashData = strHashData.Replace("-", "");                    strResult = strHashData;              }                catch (System.Exception ex)              {                  Console.WriteLine(ex.Message);              }              return strResult;          }