C# 将http在线文件，保存到服务器指定位置

将在线文件，保存到自己服务器

实现思路：1、HttpWebRequest请求该文件，获取流文件。

　　　　　 2、然后流转为byte[]

　　　　　 3、使用File类的WriteAllBytes ，将byte[] 写入文件

   [HttpPost]
        public JsonResult UploadHtppFile(string url)
        {
            try
            {
                //可以是任意文件
                url = "https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=1906469856,4113625838&fm=26&gp=0.jpg";

                //发起请求，读取流，转为byte[]
                var bytes = Url_To_Byte(url);
                //名称尽量不要重复，因为名称重复WriteAllBytes会覆盖之前的
                var fileName = DateTime.Now.ToString("yyyyMMddHHmmssms") + ".jpg";
                var filePath = "upload/" + fileName;
                //文件保存到该路径下
                System.IO.File.WriteAllBytes(Server.MapPath("~/" + filePath), bytes);

                return Json(new { code = 0, hint = "保存成功", file = filePath });
            }
            catch (Exception ex)
            {
                return Json(new { code = 1, hint = "保存失败：" + ex.Message });
                throw;
            }
        }

        /// <summary>
        /// http路径图片，转为byte[]
        /// </summary>
        /// <param name="imgUrl">图片路径</param>
        /// <returns></returns>
        public static byte[] Url_To_Byte(string imgUrl)
        {
            //创建HttpWebRequest对象，请求图片url
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(imgUrl);

            byte[] bytes;
            //获取流
            using (Stream stream = request.GetResponse().GetResponseStream())
            {
                //保存为byte[]
                using (MemoryStream mstream = new MemoryStream())
                {
                    int count = 0;
                    byte[] buffer = new byte[1024];
                    int readNum = 0;
                    while ((readNum = stream.Read(buffer, 0, 1024)) > 0)
                    {
                        count = count + readNum;
                        mstream.Write(buffer, 0, readNum);
                    }
                    mstream.Position = 0;
                    using (BinaryReader br = new BinaryReader(mstream))
                    {
                        bytes = br.ReadBytes(count);
                    }
                }
            }
            return bytes;
        }