webApi上传服务，可重命名，可创建文件夹

        /// <summary>
        /// 上传文件
        /// </summary>
        /// <returns></returns>
        [HttpPost, Route("upload")]
        public IHttpActionResult UploadFile()
        {
            string defaultPath = ConfigurationManager.AppSettings["CM.FilePath"];
            string path = HttpContext.Current.Request["Path"];
            string fileName = HttpContext.Current.Request["FileName"];
            string fullPath = defaultPath + "\\" + path; //上传路径 

            if (!Directory.Exists(fullPath))
            {
                Directory.CreateDirectory(fullPath);
            }
            List<Dictionary<String, String>> filenames = new List<Dictionary<String, String>>();
            HttpFileCollection files = HttpContext.Current.Request.Files;
            foreach (string key in files.AllKeys)
            {
                HttpPostedFile file1 = files[key];
                if (string.IsNullOrEmpty(file1.FileName) == false)
                {
                    Dictionary<String, String> dic = new Dictionary<string, string>();
                    if (string.IsNullOrWhiteSpace(fileName) == false)
                    {
　　　　　　　　　　　　　　// 重命名
                        file1.SaveAs(fullPath + "\\" + fileName);
                        dic.Add(key, path + "\\" + fileName);
                    }
                    else
                    {
                        file1.SaveAs(fullPath + "\\" + file1.FileName);
                        dic.Add(key, path + "\\" + file1.FileName);
                    }

                    filenames.Add(dic);
                }
            }
            ServerResponse response = new ServerResponse(filenames);
            return Ok(response);
        }