string path = "C:\\text.txt";

WebClient client = new WebClient();

Uri _address = new Uri(_baseAddress, "/api/Basedata/UploadDat/");

client.Headers.Add("Content-Type", "application/x-www-form-urlencoded");//长度

client.UploadFile(_address, "POST", path);

[HttpPost]

        public void UploadDat()

        {

            HttpPostedFile file = HttpContext.Current.Request.Files[];

            string strPath = ConfigurationManager.AppSettings["UploadServerDatPath"];

            if (!Directory.Exists(strPath))

            {

                Directory.CreateDirectory(strPath);

            }

            string Path = strPath + file.FileName;

            file.SaveAs(Path);

        }