无限分级Repeater递归实现：读取一次数据库，使用LINQ2SQL技术，支持排序&显示隐藏

预览效果图：

  Selenium

数据库结构：

id(int)    classname(string)   parentid(int) sort(int用于显示与排序)

1　　家居　　0　　1

2　　家电　　0　　2

3　　沙发　　1　　1

4　　某...　  3      1

...

10   ...红色   4      1

 注：

parentid  父节点ID

sort 用于隐藏或显示 兼排序功能

前台：

<asp:Repeater ID="rep" runat="server" onitemdatabound="rep_ItemDataBound">
<HeaderTemplate></HeaderTemplate>
<ItemTemplate></ItemTemplate>
<FooterTemplate></FooterTemplate>
</asp:Repeater>

后台：

public partial class 递归2 : System.Web.UI.Page
{
    public List<cmodel> list;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            rules r = new rules();
            list = r.getlist();//读取数据库
            this.rep.DataSource = list.Where(x => x.parentid == 0).ToList();//LINQ2OBJECT
            this.rep.DataBind();
        }
    }

    protected void rep_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        if (e.Item.ItemType == ListItemType.Header)
        {
            Literal l = new Literal();
            l.ID = "ul";
            l.Text="<ul>";
            e.Item.Controls.Add(l);
        }
        else if (e.Item.ItemType == ListItemType.Footer)
        {
            Literal l = new Literal();
            l.ID = "ul2";
            l.Text = "</ul>";
            e.Item.Controls.Add(l);
        }
        else if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
        {
            int id = (int)DataBinder.Eval(e.Item.DataItem, "id");
            Literal li1 = new Literal();
            li1.ID = "li1";
            li1.Text = "<li>";
            e.Item.Controls.Add(li1);

            Literal name = new Literal();
            name.ID = "n";
            name.Text = DataBinder.Eval(e.Item.DataItem, "classname").ToString();
            e.Item.Controls.Add(name);
            List<cmodel> temp = list.Where(x => x.parentid == id).ToList();//LINQ2OBJECT
            if (temp.Count > 0)
            {
                Repeater r = new Repeater();
                TemplateBuilder tb = new TemplateBuilder();
                tb.AppendLiteralString("");
                r.HeaderTemplate = tb;
                r.FooterTemplate = tb;
                r.ItemTemplate = tb;
                r.ItemDataBound += new RepeaterItemEventHandler(rep_ItemDataBound); //递归核心
                r.DataSource = temp;
                r.DataBind();
                e.Item.Controls.Add(r);
            }
            Literal li2 = new Literal();
            li2.ID = "li2";
            li2.Text = "</li>";
            e.Item.Controls.Add(li2);
        }
    }

}

使用到的类：

public class rules
{
    DataClasses1DataContext dc = new DataClasses1DataContext();

    public List<cmodel> getlist()
    {
        var q = from x in dc.ClassFJ
                where x.sort > 0  //用于控制显示隐藏
                orderby x.sort    //兼职排序功能
                select new cmodel
                (
                    x.id,
                    x.className,
                    x.parentid
                );
        return q.ToList<cmodel>();
    }
}

public class cmodel
{
    public cmodel(int i,string n,int p)
    {
        id = i;
        classname = n;
        parentid = p;
    }
    public int id { get; set; }
    public string classname { get; set; }
    public int parentid { get; set; }
}抛砖引玉，话不多讲。