may be useful

using System;
using System.Web.UI;
using System.Web.UI.WebControls;
using Common.Categories;
using DataAccess.Categories;
using Utils;
using Common.Products;
using DataAccess.Products;
using SEO;

namespace Web.Modules
{
    public partial class CategoryNavigation : UserControl
    {
        #region Classes
        public class NopCommerceLi : WebControl, INamingContainer
        {
            public NopCommerceLi()
            {
                this.HyperLink = new HyperLink();
            }

            protected override void Render(System.Web.UI.HtmlTextWriter writer)
            {
                writer.WriteBeginTag("span");
                writer.WriteAttribute("class", this.CssClass);
                if (!String.IsNullOrEmpty(this.LiLeftMargin))
                {
                    writer.WriteAttribute("style", string.Format("margin-left: {0}px", this.LiLeftMargin));
                }
                writer.Write(HtmlTextWriter.TagRightChar);
                this.HyperLink.RenderControl(writer);
                writer.WriteEndTag("span");
            }

            public string LinkText
            {
                get
                {
                    return this.HyperLink.Text;
                }
                set
                {
                    if (value != null)
                    {
                        this.HyperLink.Text = value;
                    }
                }
            }
            public HyperLink HyperLink { get; set; }

            public string LiLeftMargin
            {
                get
                {
                    object liLeftMargin = this.ViewState["LiLeftMargin"];
                    if (liLeftMargin != null)
                        return Convert.ToString(liLeftMargin);
                    return string.Empty;

                }
                set
                {
                    this.ViewState["LiLeftMargin"] = value;
                }
            }
        }
        #endregion

        protected void Page_Load(object sender, EventArgs e)
        {

        }

        #region Overrides
        protected override void CreateChildControls()
        {
            if (!this.ChildControlsCreated)
            {
                if (!this.ChildControlsCreated)
                {
                    CreateMenu();
                    base.CreateChildControls();
                    ChildControlsCreated = true;
                }
            }
        }
        #endregion

        #region Utilities
        protected void CreateMenu()
        {
            CategoryCollection breadCrumb = null;
            Category currentCategory = CategoryManager.GetCategoryById(CommonHelper.QueryStringInt("CategoryID"));
            if (currentCategory == null)
            {
                Product product = ProductManager.GetProductByID(CommonHelper.QueryStringInt("ProductID"));
                if (product != null)
                {
                    ProductCategoryCollection productCategories = CategoryManager.GetProductCategoriesByProductID(CommonHelper.QueryStringInt("ProductID"));
                    if (productCategories.Count > 0)
                        //currentCategory = productCategories[0].Category;
                        currentCategory = CategoryManager.GetCategoryById(productCategories[0].CategoryID);
                }
            }

            if (currentCategory != null)
                breadCrumb = CategoryManager.GetBreadCrumb(currentCategory.Cat_Id);
            else
                breadCrumb = new CategoryCollection();

            CreateChildMenu(breadCrumb, 0, currentCategory, 0);
        }

        protected void CreateChildMenu(CategoryCollection breadCrumb, int rootCategoryID, Category currentCategory, int level)
        {
            int padding = level++ * 15;
            foreach (Category category in CategoryManager.GetAllCategories(rootCategoryID))
            {
                NopCommerceLi link = new NopCommerceLi();
                phCategories.Controls.Add(link);

               // string categoryURL = SEOHelper.GetCategoryURL(category.Cat_Id);
                string categoryURL = null;
                if (currentCategory != null && currentCategory.Cat_Id == category.Cat_Id)
                    link.CssClass = "title";
                else
                    link.CssClass = "title";
                link.HyperLink.NavigateUrl = categoryURL;
                link.HyperLink.Text = category.Cat_Name;
                if (padding > 0)
                    link.LiLeftMargin = padding.ToString();

                for (int i = 0; i <= breadCrumb.Count - 1; i++)
                    if (breadCrumb[i].Cat_Id == category.Cat_Id)
                        CreateChildMenu(breadCrumb, category.Cat_Id, currentCategory, level);
            }
        }
        #endregion
    }
}







<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="CategoryNavigation.ascx.cs" Inherits="Web.Modules.CategoryNavigation" %>


<!-- 左侧开始//-->
      <div class="left_he">
        
         <ul class="class_menu1">    
             <asp:PlaceHolder  runat="server" ID="phCategories" /> 
    <%-- <span class="title">按菜系</span>                                  
                <li>                
                <a href="#">家常菜</a><a href="#">清爽凉菜</a><a href="#">美味糕点</a>
                <a href="#">美味粥汤</a><a href="#">药膳偏方</a><a href="#">素斋菜</a>
                <a href="#">甜品/点心</a><a href="#">料理</a>
                
        </li>
        <span class="title">按功效</span>
        <li><a href="#">美容养颜</a><a href="#">减肥</a><a href="#">增肥</a> <a href="#">丰胸</a><a
            href="#">乌发</a><a href="#">益智补脑</a> <a href="#">清热去火</a><a href="#">补虚养身</a><a href="#">滋阴壮阳</a>
        </li>
        <span class="title">按口味</span>
        <li><a href="#">清淡味</a><a href="#">家常味</a><a href="#">五香味</a> <a href="#">酸辣味</a><a
            href="#">麻辣味</a><a href="#">重辣味</a> <a href="#">咖喱味</a><a href="#">奶香味</a> </li> --%>
        
    </ul>
    <a href="#" class="upload_botton_index">
        <img src="../image/scsp_botton.jpg" /></a>
    <ul class="your_favourlist">
        <span class="title_blog">您可能会喜欢</span>
        <li>
            <img src="../image/testphoto1.gif" /><a href="#">姜葱炒海蟹</a><br />
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    </ul>
    <ul class="your_favourlist">
        <span class="title_blog">您的一周食物</span>
        <li>
        <img src="image/testphoto1.gif" /><a href="#">姜葱炒海蟹</a><br />￥36 元
        </li>
    </ul>
</div>