100分请教一个疑难问题，在线急等

Question

请教如何重写DataList控件，使其具有EmptyDataTemplate模板功能？我试了一下： public class DataList : System.Web.UI.WebControls.DataList
    {
        public DataList()
        {        }
        private ITemplate emptyDataTemplate;        [PersistenceMode(PersistenceMode.InnerProperty), TemplateContainer(typeof(TemplateControl))]
        public ITemplate EmptyDataTemplate
        {
            get { return emptyDataTemplate; }
            set { emptyDataTemplate = value; }
        }
        protected override void OnDataBinding(EventArgs e)
        {            base.OnDataBinding(e);
            if (emptyDataTemplate != null)
            {
                if (this.Items.Count == 0)
                {
                    EmptyDataTemplate.InstantiateIn(this);
                }
            }
        }
    }然后把它生成的DLL引用到网站中，但是页面中还是无法使用EmptyDataTemplate模板功能，在线急等，谢谢各位大侠！

Answer 1

http://forums.asp.net/ThreadNavigation.aspx?PostID=3343723&NavType=Next

Answer 2

public class DataListEX : System.Web.UI.WebControls.DataList
    {
        public string EmptyDataHTML { set; get; }        protected override void Render(HtmlTextWriter writer)
        {
            if (this.Items.Count == 0)
            {
                writer.Write(EmptyDataHTML);
            }
            else
            {
                base.Render(writer);
            }            
        }    }<custom:DataListEX ID="dl" runat="server" EmptyDataHTML="<span>数据为空</span>">
    <HeaderTemplate>dl H</HeaderTemplate>                
    <FooterTemplate>dl F</FooterTemplate>
    </custom:DataListEX>