根據路徑獲取獲取文件的MD5值

        /// <summary>
        /// 獲取文件MD5值
        /// </summary>
        /// <param name="filePath"></param>
        /// <returns></returns>
        private string GetMD5HashFromFile(string filePath)//多線程調用該方法會報錯-->提示文件被其他進程佔用,建議加鎖
        {
            FileStream file = new FileStream(filePath, FileMode.Open,FileAccess.Read,FileShare.Read);
            try
            {
                System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.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)
            {
                Log.WriteLog(LogFile.Error, "獲取文件MD5值出錯\r\n" + ex);
                file.Close();
                return "";
            }
        }