1、用/jquery.form.js上傳檔案，提交前判斷是否選擇了檔案（之前很糾結判斷問題，寫在beforeSend裡面不管什麼情況都會提交）

2、用ajax接收資訊

3、優化提交按鈕樣式

HTML頁面程式碼：

<script src="/JS/jquery.form.js" type="text/javascript"></script>

</script>

Ajax.ashx程式碼：

public void ProcessRequest(HttpContext context)
        {
            //操作
            string action = context.Request.QueryString["action"];

            //檢查來源
            if (!ComUtls.CheckPostSource())
            {
                context.Response.Write(ORes.Error.SuspiciousOfPostingSourceAndBeIgnored);
                return;
            }

            /****************************************
             * 加快方法呼叫響應速度,所有方法和屬性儘量以靜態的形式實現
             ***************************************/

            switch (action)
            { 

                    case "IndexSendLeaveword01": IndexSendLeaveword01(); break;

             }
        }

       /// <summary>
        /// 提交圖片
        /// </summary>
        private static void IndexSendLeaveword01()
        {
            // 獲取引數
            string upfile = GF("uploadedfile");

            string filetitle = "";
            //安全檢查
            **省略**

            string filiepath = "";
            HttpPostedFile imgFile = HttpContext.Current.Request.Files["uploadedfile"];
            if (imgFile != null)
            {
                String fileName = imgFile.FileName;
                String fileExt = System.IO.Path.GetExtension(fileName).ToLower();
                if (imgFile.InputStream == null || imgFile.InputStream.Length > 5 * 1024 * 1024)
                {
                    WriteState(0, "Upload file size limit.");
                    return;
                }
                string gs = "gif,jpg,png,docx,doc,xls,txt,pdf,rar,zip,ppt,xlsx";
                if (String.IsNullOrEmpty(fileExt) || Array.IndexOf(gs.Split(','), fileExt.Substring(1).ToLower()) == -1)
                {
                    WriteState(0, "Upload file extension is not allowed.\n Only allow" + gs + "format。");
                    return;
                }
                string path = "/uploadfiles/temporary/";
                String newFileName = DateTime.Now.ToString("yyyyMMddHHmmss_ffff", System.Globalization.DateTimeFormatInfo.InvariantInfo) + fileExt;
                try
                {
                    filiepath = path + newFileName;
                    filetitle = newFileName;
                    string save = NSW.Utls.IOUtls.GetMapPath(path);
                    if (!System.IO.Directory.Exists(save))
                    {
                        System.IO.Directory.CreateDirectory(save);
                    }
                    imgFile.SaveAs(System.IO.Path.Combine(save, newFileName));
                }
                catch (Exception ex)
                {
                    WriteState(0, ex.ToString());
                    Log.Error(ex);
                    return;
                }
            }
            else
            {
                WriteState(0, "Please select the file you want to upload.");
                return;
            }

           //填充實體
            tbTBAA nobj = new tbTBAA();
            nobj.filemane= filiepath;//上傳檔案地址

           //儲存到資料庫
            int rowsAffected = DbSession.Default.Save<tbTBAA>(nobj);
            //顯示提示
            if (rowsAffected > 0)
            {
                string msg = "Thank you for uploading the design draft, we will contact you as soon as possible.";
                WriteState(1, msg);
            }
            else
            {
                WriteState(0, "Sorry, submit failed, please try again later.");
            }

}

       /// <summary>
        /// 獲取表單值Request.Form,獲取失敗則返回 string.Empty
        /// </summary>
        /// <param name="paraName">引數名</param>
        /// <returns>引數值</returns>
        private static string GF(string paraName)
        {
            string val = HttpContext.Current.Request.Form[paraName];
            if (val == null) { return ""; }
            if (Regex.IsMatch(val, StrRegex))
            {
                HttpContext.Current.Response.Write("The parameters you submitted are not valid!");
                HttpContext.Current.Response.End();
                return "";
            }
            else
            {
                return val == null ? string.Empty : val.Trim();
            }
        }

        /// <summary>
        /// 輸出狀態值與訊息
        /// </summary>
        /// <param name="state">狀態值</param>
        /// <param name="msg">訊息</param>
        protected static void WriteState(int state, string msg)
        {
            KeyValuePair<string, string> node = new KeyValuePair<string, string>("state", state.ToString());
            KeyValuePair<string, string> node2 = new KeyValuePair<string, string>("msg", msg);
            WriteXml(node, node2);

        }

css樣式：

.up_com .upbtn{ position:relative;margin:15px 0 ; text-align:center;}
.up_com .pc{ width:211px; height:70px; line-height:70px; display:block;padding:29px 49px; text-align:center;margin:30px auto 30px; border: 1px solid #ebebeb;  box-shadow: 0 0 5px #ccc; }
.up_com .pc img{ width:70px; float:right; display:block; }
.up_com .pc a{ display:block;}
.up_com .pc .btn{font-size:16px;color:#333; line-height:70px; display:block; height:70px; float:left;}
.up_com #uploadedfile{filter:alpha(opacity=0);  -moz-opacity:0; -khtml-opacity:0;opacity: 0;width:325px; height:150px; position:absolute; top:0; left:50%;z-index:2; cursor:pointer;margin-left: -162px; }
.up_com #txtfilename{ font-size:14px; color:#333;}
.up_com .zsk7{width:200px; height:39px; line-height:39px; font-size:14px; font-weight:bold; color:#FFF; background:#6a6a6a url("Img/Index/up.png") no-repeat 30px center; border:0px;box-shadow: 2px 2px 2px 0 #a1a1a1; }