c# http文件上傳

        /// <summary>
        /// 上傳文件的api
        /// </summary>
        [HttpPost]
        public string UploadFile(op_client_billfile_info model)
        {
            string path = AppDomain.CurrentDomain.BaseDirectory + "BillFile";
            path += model.path;
            if (!Directory.Exists(path))
                Directory.CreateDirectory(path);
            model.filename = ExistFile(path, model.filename.Replace(" ", ""));

            MemoryStream ms = new MemoryStream(model.by);
            FileStream fs = new FileStream(path + "\\" + model.filename, FileMode.OpenOrCreate);
            ms.WriteTo(fs);
            ms.Close();
            fs.Close();
            return model.filename;
        }
        /// <summary>
        /// 文件名重復加（1）
        /// </summary>
        [NonAction]
        private string ExistFile(string path, string filename)
        {
            int count = 1;
            //在重復名稱后加（序號）
            while (File.Exists(path + "\\" + filename))
            {
                if (filename.Contains(")."))
                {
                    int start = filename.LastIndexOf("(");
                    int end = filename.LastIndexOf(").") - filename.LastIndexOf("(") + 2;
                    filename = filename.Replace(filename.Substring(start, end), string.Format("({0}).", count));
                }
                else
                {
                    filename = filename.Replace(".", string.Format("({0}).", count));
                }
                count++;
            }
            return filename;
        }

上傳文件類

        /// <summary>
        /// 賬單文件信息的id
        /// </summary>        
        public int bid { get; set; }
        /// <summary>
        /// 文件名
        /// </summary>        
        public string filename { get; set; }
        /// <summary>
        /// 放在服務器的路徑
        /// </summary>        
        public string path { get; set; }
        /// <summary>
        /// 文件
        /// </summary>
        public byte[] by { get; set; }

修改上傳文件大小限制，不然會報錯。第一個文件的單位是 kb  也就是100M；第二個文件的單位是 byte  也是100M。

<configuration>
  <system.web>
    <httpRuntime maxRequestLength="102400" executionTimeout="200" enable="true" />
  </system.web>
  <system.webServer>
    <security>
      <requestFiltering>
        <requestLimits maxAllowedContentLength="104857600" />
      </requestFiltering>
    </security>
  </system.webServer>
</configuration>

下載文件

        /// <summary>
        /// 保存文件
        /// url 文件地址（iis）；path 保存地址；fileName 保存文件名
        /// </summary>
        private void DownloadFile(string url, string path, string fileName)
        {
            Stream sm = WebRequest.Create(url).GetResponse().GetResponseStream();
            FileStream fs = new FileStream(path + "\\" + fileName, FileMode.OpenOrCreate);
            sm.CopyTo(fs);
            sm.Close();
            fs.Close();
        }

 post請求封裝地址：https://www.cnblogs.com/shuaimeng/p/9871582.html