kendo upload必填验证

@using Kendo.Mvc.UI
@using StudentManage.Common.Helper
@model StudentManage.Models.Home.ImportDataFromFileModel
<style>
    .hiddenBox {
        display: block;
        border: none;
        width: 0;
        height: 0
    }
</style>
<script>
    var fileName;
    function onSelect(e) {
        fileName = $("#FileName").val() + getFileInfo(e);
        $("#FileName").val(fileName);
    }
    function onRemove(e) {
        fileName = $("#FileName").val().replace(getFileInfo(e), "");
        $("#FileName").val(fileName);
    }

    function getFileInfo(e) {
        return $.map(e.files, function (file) {
            var info = file.name;
            return info;
        }).join(", ");
    }
</script>
<form action="@Url.Action("ImportDataFromFile", "Home")" id="importForm" method="post" class="panel panel-default form-horizontal panel-body">
    <div class="form-group">
        @Html.RequiredIndicatorLabelFor(m=> m.FileName, new { @class = "col-sm-3 control-label no-padding-right" })
        <div class="col-sm-4">
            @Html.HiddenFor(m => m.DataSystemName, new { @class = "form-control" })
            @(Html.Kendo().Upload().Name("files").Multiple(false).HtmlAttributes(new { accept = ".xls,.xlsx" })
                                  .Events(events => events
                                      .Remove("onRemove")
                                      .Select("onSelect")
                          ))
            @Html.TextBoxFor(m => m.FileName, new { @class = "hiddenBox" })
            @Html.ValidationMessageFor(m => m.FileName)
        </div>
    </div>
    <div class="form-group">
        <div class="col-sm-5 col-sm-offset-3">
            <button class="btn  btn-info" type="button" id="submitBtn">
                确定
            </button>
        </div>
    </div>
</form>
<script>
    $(function () {
        jQuery.validator.unobtrusive.parse();
        $('#importForm').removeData('validator');
        $('#importForm').removeData('unobtrusiveValidation');
        $.validator.unobtrusive.parse('#importForm');
        $("#submitBtn").click(function() {
            if (!$("#importForm").valid()){
                return false;
            }
            $("#importForm").submit();
            return true;
        });
    });
</script>

Action

        #region 导入导出数据
        [HttpGet]
        public ActionResult ImportDataFromFile(string dataSystemName)
        {
            ImportDataFromFileModel model = new ImportDataFromFileModel()
            {
                DataSystemName = dataSystemName
            };
            return PartialView(model);
        }

        [HttpPost]
        public async Task<ActionResult> ImportDataFromFile(IEnumerable<HttpPostedFileBase> files)
        {
            //DataTable dataTable = await NpoiHelper.ExcelToDataTable("Sheet1", true, files.First());
            //for (int i = 0; i < dataTable.Rows.Count; i++)
            //{

            //    //var enterprise = new Enterprise();
            //    //enterprise.Id = Guid.NewGuid();
            //    //if (dataTable.Rows[i][enterpriseNameColumn] != null)
            //    //{
            //    //    var content = dataTable.Rows[i][enterpriseNameColumn]?.ToString().Trim();
            //    //    var clearName = content.Length < 100 ? content : content.Substring(0, 100);
            //    //    if (enterpriseNames.Contains(clearName)) continue;
            //    //    enterprise.EnterpriseName = clearName;
            //    //}
            //}
            return RedirectToAction("Index","StudentManage");
        }

        #endregion