ASP.NET

下拉列表--------

数据库设计：

-- 无限分类 --

-- 数据库：DB_InfiniteCategory

-- 数据表：Tb_Infinite

---------------------------------------------------------------

-- 创建数据库
CREATE DATABASE DB_InfiniteCategory

-- 创建数据表
USE DB_InfiniteCategory
CREATE TABLE Tb_Infinite
(
    id int not null,                        --逻辑主键
    pid int not null,                        --父级
    categoryName varchar(10) not null        --分类名称
)


--使用语句
select id, pid, categoryName from Tb_Infinite where pid = 0

代码：

using System;
using System.Web.UI;
using System.Data;
using System.Data.SqlClient;

using DAL;
using System.Web.UI.WebControls;

namespace InfiniteCategory
{
    public partial class Default : System.Web.UI.Page
    {
        string toadd = "├";

        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                GetArticleCategory("0");
            }
        }

        public void GetArticleCategory(string pid)
        {
            SqlConnection conn = new SqlConnection(" server = HUANGFU-PC; database = DB_InfiniteCategory; integrated security = true");
            string sql = "select id,categoryName from Tb_Infinite where pid=@pid";
            SqlCommand cmd = new SqlCommand(sql, conn);
            SqlParameter Pid = new SqlParameter("@pid", SqlDbType.Int);
            Pid.Value = pid;
            cmd.Parameters.Add(Pid);
            conn.Open();
            SqlDataReader sdr = cmd.ExecuteReader();
            while (sdr.Read())
            {
                this.DropDownList1.Items.Add(new ListItem(toadd + " " + sdr[1].ToString(), sdr[0].ToString()));
                toadd += "─┴";
                this.GetArticleCategory(sdr[0].ToString());
                toadd = toadd.Substring(0, toadd.Length - 2);
            }
            sdr.Close();
            conn.Close();
        }
    }
}

最终效果：

===============================================================

导航--------

代码：

using System;
using System.Web.UI;
using System.Data;
using System.Data.SqlClient;
using System.Text;

using DAL;
using System.Web.UI.WebControls;

namespace InfiniteCategory
{
    public partial class Default : System.Web.UI.Page
    {
        StringBuilder s = new StringBuilder();

        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                GetArticleCategory("16");
            }
        }

        public void GetArticleCategory(string id)
        {
            SqlConnection conn = new SqlConnection(" server = HUANGFU-PC; database = DB_InfiniteCategory; integrated security = true");
            string sql = "select id,pid,categoryName from Tb_Infinite where id=@id";
            SqlCommand cmd = new SqlCommand(sql, conn);
            SqlParameter Pid = new SqlParameter("@id", SqlDbType.Int);
            Pid.Value = id;
            cmd.Parameters.Add(Pid);
            conn.Open();
            SqlDataReader sdr = cmd.ExecuteReader();
            while (sdr.Read())
            {
                s.Append(sdr[2].ToString()+">");
                this.GetArticleCategory(sdr[1].ToString());
            }
            this.Label1.Text = s.ToString();
            sdr.Close();
            conn.Close();
        }
    }
}

最终效果：