asp.net mvc Ajax.Actionlink routeValues作为嵌套对象

Question

我的ActionLink与routeValues：lld。

                        @Html.Raw(@Ajax.ActionLink(
                                              linkText: "[replacetext]",
                                              actionName: "StartAndCreateNewDetail",
                                              controllerName: "PpLd",
                                              routeValues: lld,
                                              ajaxOptions: new AjaxOptions { UpdateTargetId = "tblProgressbarAndAction" }
                            ).ToHtmlString().Replace("[replacetext]", "<span id='" + @btnStart + "' class='glyphicon glyphicon-play'></span>"))

lld是来自typ的对象：

public class Lld
{
    public LE le { get; set; }

    public List<LEDETAIL> lstLEDETAIL { get; set; }

    [DataType(DataType.Date)]
    public DateTime ReleaseDate { get; set; }

    public long LeErbId { get; set; }
}

控制器方法：

public ActionResult StartAndCreateNewDetail(Lld lld){

  le = lld.le; // is null
  lstLEDETAIL lstDe = lld.lstLEDETAIL; // is null
  ReleaseDate rd = lld.RealeseDate; // is not null
  LeErbId leerbid = lld.LeErbId; // is not null

}

为什么lld.le和lld.lstLEDETAIL为空？