ie下ajaxSubmit上传文件出现下载提示框问题

用ajaxSubmit上传文件，谷歌和火狐没问题，ie下js回调函数无法接受，而是弹出下载提示，百度一圈没找到解决方案，FQ谷歌了终于找了，还是老外牛

     <div class="col-sm-12">
                <form id="filePost" action="/OM/Order/SaveFile" method="post" enctype="multipart/form-data" onsubmit="return false;">
                    <input type="file" name="qtFileName" style="display: inline-block;" ng-model="qtFile" />
                    @*<a class="btn btn-sm btn-info" ng-click="fileUpload()">保存</a>*@
                    <button class="btn btn-sm btn-info" ng-click="fileUpload()">保存</button>
                    <input type="input" style="display:none;" name="roomId" ng-model="roomId" />
                </form>
            </div>

原来后台直接返json代码，ie无法出现提示

 public ActionResult SaveFile(HttpPostedFileBase qtFileName, Guid roomId)
        {
            MessageResult mr = new MessageResult();
            if (qtFileName == null || qtFileName.ContentLength == 0)
            {
                mr.Message = "请选择要上传的文档";
                return Json(mr);
            }
            string[] allowExt = new[] { ".xls", ".xlsx" };
            var extention = Path.GetExtension(qtFileName.FileName);
            if (extention == "" || !allowExt.Contains(extention))
            {
                mr.Message = "只允许上传.xls和.xlsx格式的Excel文档";
                return Json(mr);
            }
            string basePath = Server.MapPath(Excel2QTsHelper.UploadFileVirtualPath);
            if (!Directory.Exists(basePath))
            {
                Directory.CreateDirectory(basePath);
            }
            var realFileName = Path.GetFileNameWithoutExtension(qtFileName.FileName);
            var fileName = Path.Combine(basePath, roomId + extention);
            qtFileName.SaveAs(fileName);
            try
            {
                var orderVos = _excel2QTsHelper.Excel2QTs(roomId, null);
                bool result = _courseOrderProxy.CreateOrders(orderVos);
                if (result)
                {
                    mr.Success = true;
                    mr.Message = "上传成功";
                    return Json(mr, "text/html", System.Text.Encoding.UTF8,
                     JsonRequestBehavior.AllowGet);
                }
            }
            catch (Exception e)
            {
                mr.Success = false;
                mr.Message =e.Message;
                return Json(mr, "text/html", System.Text.Encoding.UTF8,
                       JsonRequestBehavior.AllowGet);
            }
            return Json(mr, "text/html", System.Text.Encoding.UTF8,
                        JsonRequestBehavior.AllowGet);
        }

　　老外给出答案：

If anyone is using ASP.net MVC and trying to fix this issue - I used the following built in methods in the MVC framework. Simply update the content Type and encoding on the JsonResult.

public ActionResult Index(int id)
{
        // Fetch some data
        var someData = GetSomeData();

        // Return and update content type and encoding
        return Json(someData, "text/html", System.Text.Encoding.UTF8,
                        JsonRequestBehavior.AllowGet);
}
由于返回来的是字符串，所以还有转为json对象

 $scope.fileUpload = function () {
            var options = {
                beforeSubmit: function () {
                },
                error: function () {
                    alert("上传失败");
                },
                success: function (data) {
                    var data = $.parseJSON(data);
                    if (data.Success) {
                        alert("上传成功");
                    } else {
                        alert(data.Message || "上传失败");
                    }
                }
            };
            $('#filePost').ajaxSubmit(options);
        };

　　完美解决！