public ActionResult Edit(User model)
 {
     new UserService().Update(model);
     return Json(new AjaxResult("修改成功", AjaxResultType.Success, null));
 }
 public ActionResult Add(User model)
 {
     new UserService().Add(model);
     return Json(new AjaxResult("添加成功", AjaxResultType.Success, null));
 }