想做一个二级分类的绑定

Question

现在有了一级分类的id
现在要绑定一级分类id为1的所有的二级分类
现在不知道绑定怎么写了，绑定出来的二级分类要是   超链接的格式那位会写代码啊，给我点思路也行啊

Answer 1

后台代码
ds = mc.SelectData("select * from FirstClass", "first");
        try
        {
            DataTable dt = des.Tables["first"];
            dl.DataSource = dt;
            dl.DataBind();
            ds = mc.SelectData("select id as sid,secondname,fid from SecondClass", "second");
            DataView sdv = ds.Tables["second"].DefaultView;            for (int i = 0; i < dt.Rows.Count; i++)
            {
                DataRow dr = dt.Rows[i];
                sdv.RowFilter = "fid = " + dr["id"].ToString();
                DataList dal = (DataList)dl.Items[i].FindControl(name);
                dal.DataSource = sdv;
                dal.DataBind();
            }
        }
        catch (Exception ex)
        {            Response.Write("<script>alert('"+ex.Message+"')</script>");
        }
前台代码
<asp:DataList ID="dlf" runat="server" Width="222px">
                                <ItemTemplate>
                                <table width="100%">
                                    <tr>
                                        <td onclick="show(<%#Eval("id") %>)" id="td<%#Eval("id") %>" class="STYLE37" style="font-size:12;cursor:pointer;height:28px; background-image: url(images/t1.jpg);">
                                             <%#Eval("firstname") %>
                                        </td>
                                    </tr>
                                    <tr style="display:none;cursor:pointer;font-size:12pt; background-color: aliceblue;" id="left<%#Eval("id") %>" class="STYLE38" >
                                        <td>
                                                <asp:DataList ID="dls" runat="server">
                                                <ItemTemplate>
                                                <div onmouseover="this.className='l1'" onmouseout="this.className='l2'">
                                                   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a  style="font-size:10pt" href="product.aspx?id=<%#Eval("sid") %>"> <%#Eval("secondname") %></a></div>
                                                </ItemTemplate>
                                                </asp:DataList>
                                            </td>
                                    </tr>
                                </table>
                            
                        </ItemTemplate>
                                <ItemStyle HorizontalAlign="Center" VerticalAlign="Top" Font-Size="12pt" />
                    </asp:DataList>

Answer 2

忘了JS了
var o = "";
        function show(id)
        {
            var obj = document.getElementById("left"+id);
            var m = document.getElementById("td"+id);
            if(obj.style.display == "none" || obj.style.display == "")
            {
                obj.style.display = "block";
                if(o != "")
                {
                    document.getElementById("left"+o).style.display = "none";
                    document.getElementById("td"+o).style.background = "url(images/t1.jpg)";
                    m.style.background = "url(images/t2.jpg)";
                    o = id;
                }
                else
                {
                    m.style.background = "url(images/t2.jpg)";
                    o = id;
                }
            }
            else
            {
                m.style.background = "url(images/t1.jpg)";
                obj.style.display = "none";
                o = "";
            }
        }

Answer 3

参考: 
表结构 
id  supid(父级)  titlename 
---------------------------- 
1    0          A 
2    1          B 
3    1          C 
的这种格式 using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;/// <summary>
/// DropDownList 的摘要说明
/// </summary>
public class DropDownListTree
{    ///   <summary>   
    ///   树形DropDownList绑定   
    ///   </summary>   
    ///   <param   name="sql">sql语句</param>   
    ///   <param   name="dropParent">绑定数据的控件ID</param>   
    ///   <param   name="strID">表的 标示列的字段名</param>   
    ///   <param   name="strName">要显示文本的字段名</param>   
    ///   <param   name="strPid">父例字段名称</param>   
    public void BindDropList(string sql, DropDownList dropParent, string strID, string strName, string strPid)
    {
        DataTable dt = Diancheng.DAL.Data.FillDataTable(CommandType.Text, sql, null);
        if (dt.Rows.Count > 0)
        {
            foreach (DataRow row in dt.Rows)
            {
                if (row[strPid].ToString().Trim() == "0")//绑定根节点   
                {
                    dropParent.Items.Add(new ListItem(row[strName].ToString(), row[strID].ToString()));
                    bindDropChildItem(dropParent, dt, row[strID].ToString(), 1, strID, strName, strPid);
                }
            }
        }
    }    private void bindDropChildItem(DropDownList d, DataTable dt, string id, int length, string strID, string strName, string strPid)
    {
        DataRow[] rows = dt.Select(strPid + "=" + id);//取出id子节点   
        for (int i = 0; i < rows.Length; i++)
        {
            d.Items.Add(new ListItem(this.SpaceLength(length) + rows[i][strName].ToString(), rows[i][strID].ToString()));
            //无限级加   
            this.bindDropChildItem(d, dt, rows[i][strID].ToString(), length - 1, strID, strName, strPid);//空白数目加1   
        }
    }    private string SpaceLength(int i)
    {
        string space = "";
        for (int j = 0; j < i; j++)
        {
            space = "　└─";//用做显示   
        }
        return space;
    }
}