Oss.OssClient.GetObject C# (CSharp) Метод

        public async Task<ObjectMetadata> GetObject(GetObjectRequest getObjectRequest, Stream output,
            Action<HttpProcessData> downloadProcessCallback = null, CancellationToken? cancellationToken = null)
        {
            OssObject ossObject = await this.GetObject(getObjectRequest, downloadProcessCallback, cancellationToken);
            using (ossObject.Content)
            {
                ossObject.Content.CopyTo(output);
            }
            return ossObject.Metadata;
        }

        static async void getObject()
        {
            try
            {
                OssClient temp = new OssClient("bm9crcnr0rtnuw8bnrfvq7w8", "RbtJoExTnA8vYLynUfDh7Ior+oM=");
                OssObject result = await temp.GetObject("devdoc", "c# 5.0.pdf", callback);

                

                  
                FileStream fs = new FileStream(@"C:\Users\yangzhl\Desktop\c# 5.0.pdf", FileMode.Open);
                byte[] buffer = new byte[fs.Length];
                result.Content.Read(buffer, 0, buffer.Length);
                byte[] sh = MD5.Create().ComputeHash(buffer);
               string hashCode = BitConverter.ToString(sh).Replace("-", string.Empty).ToLower();


            }
            catch (AggregateException ex)
            {
                Console.WriteLine(ex.Message);

            }
        }