第一種通過 Form表單形式

（適用於 JS、Android、IOS等平臺）

/// <summary>
        /// 上傳檔案
        /// </summary>
        /// <returns></returns>
        [HttpPost]
        public string PostFiles()
        {
            string result = "";
            HttpFileCollection filelist = HttpContext.Current.Request.Files;
            if (filelist != null && filelist.Count > 0)
            {
                for (int i = 0; i < filelist.Count; i++)
                {
                    HttpPostedFile file = filelist[i];
                    String Tpath =  "/" + DateTime.Now.ToString("yyyy-MM-dd") + "/";
                    string filename = file.FileName;
                    string FileName = DateTime.Now.ToString("yyyyMMddHHmmssfff") ;
                    string FilePath = 儲存路徑+ "\\" + Tpath + "\\";
                    DirectoryInfo di = new DirectoryInfo(FilePath);
                    if (!di.Exists) { di.Create(); }
                    try
                    {
                        file.SaveAs(FilePath + FileName);
                        result.obj =(Tpath + FileName).Replace("\\", "/");
                    }
                    catch (Exception ex)
                    {
                        result= "上傳檔案寫入失敗：" + ex.Message;
                    }
                }
            }
            else
            {
                result = "上傳的檔案資訊不存在！";
            }
            
            return result;
        }
 

  /// <summary>
        /// 檔案上傳
        /// </summary>
        /// <param name="filename">檔名稱</param>
        /// <param name="FileContent">檔案內容</param>
        /// <returns></returns>
        [HttpPost]
        public string PostFile([FromUri]string filename, [FromBody] byte[] FileContent)
        {
            string result = "";
            if (FileContent != null)
            {
                String Tpath =  "/" + DateTime.Now.ToString("yyyy-MM-dd") + "/";
                string FilePath = 儲存路徑 + "\\" + Tpath+"\\";
                String Err = "";
                string FileName = DateTime.Now.ToString("yyyyMMddHHmmssfff");
                bool upres = FileUtil.WriteFile(FilePath, FileContent, FileName, out Err);
                if (upres)
                {
                    result= (Tpath + FileName).Replace("\\", "/");
                }
                else
                {
                    result= "上傳檔案寫入失敗：" + Err;
                }
            }
            else
            {
                result= "上傳的檔案資訊不存在！";
            }
            return result;
        }
 

/// <summary>
        /// 二進位制流寫入檔案
        /// </summary>
        /// <param name="filepath">檔案路徑</param>
        /// <param name="filecontent">檔案內容</param>
        /// <param name="FileName">檔名</param>
        /// <param name="Errmsg">錯誤訊息</param>
        /// <returns></returns>
        public static bool WriteFile(string filepath, byte[] filecontent, string FileName,out string Errmsg)
        {
            DirectoryInfo di = new DirectoryInfo(filepath);
            if (!di.Exists)
            {
                di.Create();
            }
            FileStream fstream = null;
            try
            {
                fstream = File.Create(filepath + "\\" + FileName, filecontent.Length);

                fstream.Write(filecontent, 0, filecontent.Length);   //二進位制轉換成檔案
            }
            catch (Exception ex)
            {
                Errmsg = ex.Message;
                //丟擲異常資訊
                return false;
            }
            finally
            {
                if(fstream!=null)
                fstream.Close();
            }
            Errmsg = "";
            return true;
        }