无限极分类下拉框

[whoo529]

数据表结构
id parentid typename
1 1 湖北
2 2 广州
3 3 湖南
4 1 武汉
5 1 黄石
6 2 广州
7 6 天河
8 6 白云
...

id=parentid 为最大类，没有“深度”字段，
做成无限极下来框该如何绑定？

[jiaxfandy]

[Quote=引用 19 楼 CutBug 的回复:]
写了一个DataTable数据源的
dropdownlist ID:AreaSource

C# codepublic partial class _Default : System.Web.UI.Page
{
DataView dv;
/// <summary>
/// 层次分割符
/// </summary>
const string STR_TREENODE = "┆┄";
/// <summary>
/// 顶级父节点parentid
/// </summary>
const int INT_TOPID = 0;

const string STR_ID = "id";
const string STR_PARENT…
[/Quote]


不好意思引用错误 呵呵

[whoo529]

正解，谢谢

大家好好理解下递归，这个案例是最常用的了

[whoo529]

/// <summary>
    /// 递归绑定DropDownList
    /// </summary>
    /// <param name="pid"></param>
    /// <param name="schar"></param>
    private void RecursBind(int pid, ref string schar, DropDownList dp)
    {
        if (pid == -1)
        {
            foreach (DataRow row in dv.Table.Rows)
            {
                if (Convert.ToInt32(row[STR_ID]) == Convert.ToInt32(row[STR_PARENTID]))
                {
                    dp.Items.Add(new ListItem(schar + row[STR_DISPLAYNAME].ToString(), row[STR_ID].ToString()));
                    RecursBind(Convert.ToInt32(row[STR_ID]), ref schar,dp);
                }
            }
        }
        else
        {
            DataRowView[] rows = dv.FindRows(pid);
            foreach (DataRowView row in rows)
            {
                if (Convert.ToInt32(row[STR_ID]) != Convert.ToInt32(row[STR_PARENTID]))
                {
                    schar += STR_TREENODE;
                    dp.Items.Add(new ListItem(schar + row[STR_DISPLAYNAME].ToString(), row[STR_ID].ToString()));
                    RecursBind(Convert.ToInt32(row[STR_ID]), ref schar, dp);
                }

            }
            schar = STR_TREENODE;
        }
    }

[whoo529]

调试了一下19楼的，确实没问题，但我的最大类不是parentid==0；
最大类是parentid==id

有点小问题

[spark_wu]

根类的parentid 还是=0好，不然你怎么判断是不是根节点呢
好像有点麻烦啊

[codetian]

我也来写一下
public partial class UserWebControl_ctlTradeType : System.Web.UI.UserControl
{
string toadd = null;

protected override void OnInit(EventArgs e)
{
base.OnInit(e);
GetTradeType("0");
}

protected void Page_Load(object sender, EventArgs e)
{

}

public string SelectedValue
{
get { return ddlTradeType.SelectedValue; }
set { ddlTradeType.SelectedValue = value; }
}


private void GetTradeType(string pid)
{
DAL.DBAccess db = DAL.DBConnection.CreateDB();
DataTable dt = db.ExecuteQuery("select * from P_TradeType where parentId=" + pid);
foreach (DataRow row in dt.Rows)
{
string name = row["TName"].ToString();
string id = row["ID"].ToString();
this.ddlTradeType.Items.Add(new ListItem(toadd + " " + row["TName"].ToString(), row["ID"].ToString()));
toadd += "┴─";
this.GetTradeType(row["id"].ToString());
toadd = toadd.Substring(0, toadd.Length - 2); //处理层次关系显示
}
}
}

[悔说话的哑巴]

[Quote=引用 2 楼 guzhonghua 的回复:]
绑定还是那也绑定，只是查询的时候你用Parenetid=id就可以了。
例如：
select * from
tablename where parentid=页面上的当前ID
[/Quote]
这个方法可以拉

[huxuanhui]

偶用js写了一个
楼主要的话给我消息

QQ 289184118

[CutBug]

依照你的要求改了一下

 public partial class Default : System.Web.UI.Page
    {
        DataView dv;
        /// <summary>
        /// 层次分割符
        /// </summary>
        const string STR_TREENODE = "┆┄";
        const string STR_ID = "id";
        const string STR_PARENTID = "parentid";
        const string STR_DISPLAYNAME = "typename";

        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                dv = new DataView(this.AreaSource);
                dv.Sort = STR_PARENTID;
                string schar = STR_TREENODE;
                if (dv.Table.Rows.Count > 0)
                {
                    RecursBind(-1,ref schar);
                }
            }
        }

        /// <summary>
        /// 递归绑定DropDownList
        /// </summary>
        /// <param name="pid"></param>
        /// <param name="schar"></param>
        private void RecursBind(int pid,ref string schar)
        {
            if (pid == -1)
            {
                foreach (DataRow row in dv.Table.Rows)
                {
                    if (Convert.ToInt32(row[STR_ID]) == Convert.ToInt32(row[STR_PARENTID]))
                    {
                        this.AreaList.Items.Add(new ListItem(schar + row[STR_DISPLAYNAME].ToString(), row[STR_ID].ToString()));
                        RecursBind(Convert.ToInt32(row[STR_ID]), ref schar);
                    }
                }
            }
            else
            {
                DataRowView[] rows =  dv.FindRows(pid);
                foreach (DataRowView row in rows)
                {
                    if (Convert.ToInt32(row[STR_ID]) != Convert.ToInt32(row[STR_PARENTID]))
                    {
                        schar += STR_TREENODE;
                        this.AreaList.Items.Add(new ListItem(schar + row[STR_DISPLAYNAME].ToString(), row[STR_ID].ToString()));
                        RecursBind(Convert.ToInt32(row[STR_ID]), ref schar);
                    }
                    
                }
                schar = STR_TREENODE;
            }
        }

        /// <summary>
        /// 测试数据源
        /// </summary>
        private DataTable AreaSource
        {
            get
            {
                DataTable dt = new DataTable();
                dt.Columns.Add(new DataColumn(STR_ID, typeof(int)));
                dt.Columns.Add(new DataColumn(STR_PARENTID, typeof(int)));
                dt.Columns.Add(new DataColumn(STR_DISPLAYNAME, typeof(string)));

                dt.Rows.Add(new object[] { 1, 1, "湖北" });
                dt.Rows.Add(new object[] { 2, 2, "江苏" });
                dt.Rows.Add(new object[] { 3, 3, "浙江" });
                dt.Rows.Add(new object[] { 4, 1, "黄冈" });
                dt.Rows.Add(new object[] { 5, 4, "黄冈镇级" });
                dt.Rows.Add(new object[] { 6, 5, "黄冈村" });
                dt.Rows.Add(new object[] { 7, 3, "杭州" });
                dt.Rows.Add(new object[] { 8, 2, "南京" });
                return dt;
            }
        }
    }

[stonehy520]

学习

[zhaoqiliang527]

关注！！！

[whoo529]

/// <summary>
    /// 测试数据源
    /// </summary>
    private DataTable AreaSource
    {
        get
        {
            DataTable dt = new DataTable();
            dt.Columns.Add(new DataColumn(STR_ID, typeof(int)));
            dt.Columns.Add(new DataColumn(STR_PARENTID, typeof(int)));
            dt.Columns.Add(new DataColumn(STR_DISPLAYNAME, typeof(string)));

            dt.Rows.Add(new object[] { 1, 1, "湖北" });
            dt.Rows.Add(new object[] { 2, 1, "武汉" });
            dt.Rows.Add(new object[] { 3, 2, "汉口" });
            dt.Rows.Add(new object[] { 4, 2, "汉阳" });
            dt.Rows.Add(new object[] { 5, 4, "蔡甸" });
            dt.Rows.Add(new object[] { 6, 4, "汉南" });
            dt.Rows.Add(new object[] { 7, 1, "黄冈" });
            dt.Rows.Add(new object[] { 8, 7, "黄冈镇级" });
            dt.Rows.Add(new object[] { 9, 7, "黄冈村" });
            dt.Rows.Add(new object[] { 10, 10, "南京" });

            return dt;
        }
    }

我的数据是有两个三级分类就会只显示出一条来，其他的三级都在二级下

[whoo529]

漏洞在超过第二个分类的数据超过两条以上只会显示出一条正常数据，其他的都在二级分类里面

private DataTable AreaSource
    {
        get
        {
            DataTable dt = new DataTable();
            dt.Columns.Add(new DataColumn(STR_ID, typeof(int)));
            dt.Columns.Add(new DataColumn(STR_PARENTID, typeof(int)));
            dt.Columns.Add(new DataColumn(STR_DISPLAYNAME, typeof(string)));

            dt.Rows.Add(new object[] { 1, 1, "湖北" });
            dt.Rows.Add(new object[] { 2, 2, "江苏" });
            dt.Rows.Add(new object[] { 3, 3, "浙江" });
            dt.Rows.Add(new object[] { 4, 1, "黄冈" });
            dt.Rows.Add(new object[] { 5, 4, "黄冈镇级" });
            dt.Rows.Add(new object[] { 6, 5, "黄冈村" });
            dt.Rows.Add(new object[] { 7, 3, "杭州" });
            dt.Rows.Add(new object[] { 8, 2, "南京" });
            dt.Rows.Add(new object[] { 9, 6, "黄冈村下级" });
            dt.Rows.Add(new object[] { 10, 7, "杭州区" });
            dt.Rows.Add(new object[] { 11, 8, "南京区" });
            dt.Rows.Add(new object[] { 12, 11, "南京区下级1" });
            dt.Rows.Add(new object[] { 13, 11, "南京区下级2" });
            dt.Rows.Add(new object[] { 14, 12, "南京区下级1的下级" });
            return dt;
        }
    }

”南京区下级2“ 就会有问题

[CutBug]

/// <summary>
    /// 递归绑定DropDownList
    /// </summary>
    /// <param name="pid"></param>
    /// <param name="schar"></param>
    private void RecursBind(int pid, ref string schar)
    {
        
        if (pid == -1)
        {
            foreach (DataRow row in dv.Table.Rows)
            {
                if (Convert.ToInt32(row[STR_ID]) == Convert.ToInt32(row[STR_PARENTID]))
                {
                    this.AreaList.Items.Add(new ListItem(schar + row[STR_DISPLAYNAME].ToString(), row[STR_ID].ToString()));
                    Response.Write(schar + row[STR_DISPLAYNAME].ToString()+"<br>");
                    RecursBind(Convert.ToInt32(row[STR_ID]), ref schar);
                }
            }
        }
        else
        {
           
            DataRowView[] rows = dv.FindRows(pid);
            string temp=null;
            for(int i=0;i<rows.Length;i++)
            {
                if (Convert.ToInt32(rows[i][STR_ID]) != Convert.ToInt32(rows[i][STR_PARENTID]))
                {
                    if (temp == null) temp = schar;
                    schar += STR_TREENODE;
                    Response.Write(schar + rows[i][STR_DISPLAYNAME].ToString() + "<br>");
                    this.AreaList.Items.Add(new ListItem(schar + rows[i][STR_DISPLAYNAME].ToString(), rows[i][STR_ID].ToString()));
                    RecursBind(Convert.ToInt32(rows[i][STR_ID]), ref schar);
                    schar = temp;
                }

            }
        }
    }

┆┄湖北
┆┄┆┄黄冈
┆┄┆┄┆┄黄冈镇级
┆┄┆┄┆┄┆┄黄冈村
┆┄┆┄┆┄┆┄┆┄黄冈村下级
┆┄┆┄┆┄┆┄黄冈村二
┆┄┆┄┆┄黄冈镇级二
┆┄┆┄武汉
┆┄江苏
┆┄┆┄南京
┆┄┆┄┆┄南京区
┆┄┆┄┆┄┆┄南京区下级
┆┄┆┄┆┄┆┄┆┄南京区下级的下级
┆┄浙江
┆┄┆┄杭州
┆┄┆┄┆┄杭州区
┆┄┆┄宁波

[CutBug]

我看一下

[CutBug]

你的数据是不是有问题，下面是我做的5级测试数据，没问题

using System;
using System.Data;
using System.Collections.Generic;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Text;
using System.Text.RegularExpressions;
using System.Xml;
using System.IO;
using System.Reflection;
using System.Net;
public partial class Default5 : System.Web.UI.Page
{
    DataView dv;
    /// <summary>
    /// 层次分割符
    /// </summary>
    const string STR_TREENODE = "┆┄";
    const string STR_ID = "id";
    const string STR_PARENTID = "parentid";
    const string STR_DISPLAYNAME = "typename";

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            dv = new DataView(this.AreaSource);
            dv.Sort = STR_PARENTID;
            string schar = STR_TREENODE;
            if (dv.Table.Rows.Count > 0)
            {
                RecursBind(-1, ref schar);
            }
        }
    }

    /// <summary>
    /// 递归绑定DropDownList
    /// </summary>
    /// <param name="pid"></param>
    /// <param name="schar"></param>
    private void RecursBind(int pid, ref string schar)
    {
        if (pid == -1)
        {
            foreach (DataRow row in dv.Table.Rows)
            {
                if (Convert.ToInt32(row[STR_ID]) == Convert.ToInt32(row[STR_PARENTID]))
                {
                    this.AreaList.Items.Add(new ListItem(schar + row[STR_DISPLAYNAME].ToString(), row[STR_ID].ToString()));
                    RecursBind(Convert.ToInt32(row[STR_ID]), ref schar);
                }
            }
        }
        else
        {
            DataRowView[] rows = dv.FindRows(pid);
            foreach (DataRowView row in rows)
            {
                if (Convert.ToInt32(row[STR_ID]) != Convert.ToInt32(row[STR_PARENTID]))
                {
                    schar += STR_TREENODE;
                    this.AreaList.Items.Add(new ListItem(schar + row[STR_DISPLAYNAME].ToString(), row[STR_ID].ToString()));
                    RecursBind(Convert.ToInt32(row[STR_ID]), ref schar);
                }

            }
            schar = STR_TREENODE;
        }
    }

    /// <summary>
    /// 测试数据源
    /// </summary>
    private DataTable AreaSource
    {
        get
        {
            DataTable dt = new DataTable();
            dt.Columns.Add(new DataColumn(STR_ID, typeof(int)));
            dt.Columns.Add(new DataColumn(STR_PARENTID, typeof(int)));
            dt.Columns.Add(new DataColumn(STR_DISPLAYNAME, typeof(string)));

            dt.Rows.Add(new object[] { 1, 1, "湖北" });
            dt.Rows.Add(new object[] { 2, 2, "江苏" });
            dt.Rows.Add(new object[] { 3, 3, "浙江" });
            dt.Rows.Add(new object[] { 4, 1, "黄冈" });
            dt.Rows.Add(new object[] { 5, 4, "黄冈镇级" });
            dt.Rows.Add(new object[] { 6, 5, "黄冈村" });
            dt.Rows.Add(new object[] { 7, 3, "杭州" });
            dt.Rows.Add(new object[] { 8, 2, "南京" });
            dt.Rows.Add(new object[] { 9, 6, "黄冈村下级" });
            dt.Rows.Add(new object[] { 10, 7, "杭州区" });
            dt.Rows.Add(new object[] { 11, 8, "南京区" });
            dt.Rows.Add(new object[] { 12, 11, "南京区下级" });
            dt.Rows.Add(new object[] { 13, 12, "南京区下级的下级" });
            return dt;
        }
    }
}

[lzs159263]

用递归+循环就可以了

[libo12388900bo]

递归+循环的 代码 怎么写呢 小弟请教！

[chunquanwang]

刚才正好用到，谢了

[lcomplete]

19楼不错