上下主题

protected void Page_Load(object sender, EventArgs e)
        {
            int.TryParse(Request["ID"], out queryID);
            if (!IsPostBack)
            {
                BindData(queryID); 
            }
        }

        public void BindData(int ID)
        {
            var result = from f in siteData.共青团_团建活动
                         where f.Id == ID
                         orderby f.创建时间 descending
                         select new
                         {
                             ID=f.Id,
                             创建时间=f.创建时间,
                             标题=f.标题,
                             正文=f.正文
                         };
            fv_PartyActivity.DataSource = result;
            fv_PartyActivity.DataBind();
            ViewState["ID"] = ID;
            ViewState["Title"] = result.FirstOrDefault().标题;
        
        }
 protected void PrePage_Click(object sender, EventArgs e)
        {
            var result = siteData.共青团_团建活动.OrderByDescending(item => item.创建时间).ToList();
            int index  =  result.FindIndex(item => item.Id== Convert.ToInt32(ViewState["ID"]));
            if (index > 0)
            {
                index--;
                if (result.ElementAt(index).Id.HasValue)
                {
                    int ID = result.ElementAt(index).Id.Value;
                    BindData(ID);
                }  
            }
        }

        protected void NextPage_Click(object sender, EventArgs e)
        {
            var result = siteData.共青团_团建活动.OrderByDescending(item => item.创建时间).ToList();
            int index = result.FindIndex(item => item.Id == Convert.ToInt32(ViewState["ID"]));
            if (index < result.Count() - 1)
            {
                index++;
                if (result.ElementAt(index).Id.HasValue)
                {
                    int ID = result.ElementAt(index).Id.Value;
                    BindData(ID);
                }  
            }
        }