操作字节流方法

 public static byte[] RetrieveBytesFromStream(Stream stream)
        {

            List<byte> lst = new List<byte>();
            byte[] data = new byte[1024];
            int totalCount = 0;
            while (true)
            {
                int bytesRead = stream.Read(data, 0, data.Length);
                if (bytesRead == 0)
                {
                    break;
                }
                byte[] buffers = new byte[bytesRead];
                Array.Copy(data, buffers, bytesRead);
                lst.AddRange(buffers);
                totalCount += bytesRead;
            }
            return lst.ToArray();
        }