C# 获取文件MD5值的方法

可用于对比文件是否相同

 /// <summary>
         /// 获取文件MD5值
         /// </summary>
         /// <param name="fileName">文件绝对路径</param>
         /// <returns>MD5值</returns>
         public static string GetMD5HashFromFile(string fileName)
         {
             try
             {
                 FileStream file = new FileStream(fileName, FileMode.Open);
                 System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
                 byte[] retVal = md5.ComputeHash(file);
                 file.Close();

                 StringBuilder sb = new StringBuilder();
                 for (int i = ; i < retVal.Length; i++)
                 {
                     sb.Append(retVal[i].ToString("x2"));
                 }
                 return sb.ToString();
             }
             catch (Exception ex)
             {
                 throw new Exception("GetMD5HashFromFile() fail,error:" + ex.Message);
             }
         }