asp.net - onitemdatabound 在回发后不起作用

Question

这是我的页面代码。我只想显示我的记录。页面上还有搜索面板。在搜索面板中，有几个下拉列表控件，它们具有 OnSelectedIndexChanged 方法。当我更改第一个下拉列表中的选定项目时，属于中继器的 onItemDatabound 事件不再起作用。

相反会发生什么：在这种情况ItemDataBound下，我会在面板上动态添加每条记录的图片。因此，当我更改下拉列表的选定项目时，图片会消失。

 protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        DataBindToPage();            
    }
}

protected void DataBindToPage()
{
    rptLast.DataSource = EntitiyProvider.GetAdvertListLatest();
    rptLast.DataBind();

    rptSchool.DataSource = EntitiyProvider.GetAdvertListLatest("Ders Kitabı");
    rptSchool.DataBind();

    rptBook.DataSource = EntitiyProvider.GetAdvertListLatest("Edebi Eser");
    rptBook.DataBind();
}

protected void rptLast_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)
    {
        Advert adv = (Advert)e.Item.DataItem;            
        Panel pnlLastAdvertPic = (Panel)e.Item.FindControl("pnlLastAdvertPic");
        List<AdvertPicture> advPic = EntitiyProvider.GetAdvertKapakPicByAdvertId(adv.id);
        if (advPic.Count != 0)
        {
            string picPath = string.Empty;
            foreach (AdvertPicture item in advPic)
            {
                if (item.primePicture == true)
                {
                    picPath = item.picturePath;
                }
            }
            if (picPath == string.Empty)
            {
                pnlLastAdvertPic.Controls.Add(new Image { ImageUrl = "~/uploads/" + advPic[0].picturePath, Width = 140, CssClass="rpTable" });
            }
            else
            {
                pnlLastAdvertPic.Controls.Add(new Image { ImageUrl = "~/uploads/" + picPath, Width = 140, CssClass = "rpTable" });
            }
        }
        else
        {
            pnlLastAdvertPic.Controls.Add(new Image { ImageUrl = "~/images/Noimage.gif", Width = 120, CssClass = "rpTable" });
        }

     }           

 }