I use HttpPostedFileBase as model for the file, but the files comes Null to the controller, I want to use the AjaxForm tha Asp.net provides not the regular BeginForm i need to post this throw ajax ?
   @using (Ajax.BeginForm("UploadImg", "Controller", Object,
  new AjaxOptions { HttpMethod ="Post", OnComplete = "Something();" },
  new { enctype = "multipart/form-data" }))
                {
                    @Html.AntiForgeryToken()
                    <div class="form-horizontal">
                        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
                        <div class="form-group">
                            <div class="col-lg-7">
@Html.TextBoxFor(model => model.File, new { type = "file", @class = "form-control", required = "required" })
                <input type="submit" value="Upload" class="btn-primary" />
                            </div>
                        </div>
                    </div>
        }
