public ActionResult RemovePost(int id, int pid)
        {
            Seminar seminar = SeminarBll.GetById(id);
            Post    post    = PostBll.GetById(pid);

            seminar.Post.Remove(post);
            bool b = SeminarBll.UpdateEntitySaved(seminar);

            return(ResultData(null, b, b ? $"已成功将【{post.Title}】从专题【{seminar.Title}】移除" : "添加失败!"));
        }