layui upload 后臺獲取不到值

后臺獲取不到值方法一：

<script>layui.use('upload', function () {var upload = layui.upload;//執行實例var uploadInst = upload.render({elem: '#test1' //綁定元素, url: '/Home/UploadFiles' //上傳接口  , field: "fileNames"     //添加這個屬性與后臺名稱保存一致, accept: 'file' //允許上傳的文件類型, size: 500000 //最大允許上傳的文件大小, before: function (obj) { //obj參數包含的信息，跟 choose回調完全一致，可參見上文。layer.load(); //上傳loading
            }, done: function (res) {//上傳完畢回調
                alert(res.tc);}, error: function () {//請求異常回調
            }});});
</script>

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 public ActionResult UploadFiles(HttpPostedFileBase fileNames){string path = "";//小于20Mif (fileNames.ContentLength > 0 && fileNames.ContentLength <= 120971520){var fileName = Path.GetFileName(fileNames.FileName);string q_FN = fileName.Substring(0, fileName.LastIndexOf("."));string h_FN = fileName.Substring(fileName.LastIndexOf("."));string NewFileName = q_FN + DateTime.Now.ToString("yyyyMMddHHmmss") + h_FN;path = Path.Combine(Server.MapPath("/Uploadfile/"), NewFileName);fileNames.SaveAs(path);path = "/Uploadfile/" + NewFileName;var relt = new { tc = path };return Content(JsonConvert.SerializeObject(relt));}else{var relt = new { tc = "上傳文件要小于20M" };return Content(JsonConvert.SerializeObject(relt));}}

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