C#如何将公网url地址的文件（pdf）转成byte字节

声明方法

        /// <summary>
        /// 用远程地址获取文件字节流
        /// </summary>
        /// <param name="path">URL</param>
        /// <returns></returns>
        private byte[] GetUrlMemoryStream(string path)
        {

            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(path);
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream responseStream = response.GetResponseStream();

            List<byte> btlst = new List<byte>();
            int b = responseStream.ReadByte();
            while (b > -1)
            {
                btlst.Add((byte)b);
                b = responseStream.ReadByte();
            }
            byte[] bts = btlst.ToArray();
            return bts;
        }

调用

                 var bytes = GetUrlMemoryStream(fileurl);
                //可用  MemoryStream和FileStream都是继承于stream 
                //FileStream只能打开file文件 写入本地 是存在file磁盘中
                //MemoryStream存在内存中 有长度限制
                Stream stream = new MemoryStream(bytes);