ASP.NET实现无限类下拉选择

ASP.NET无限类下拉选择实现效果图

实现方法：

.aspx文件内容

<asp:Label ID="GroupIdlab" runat="server"></asp:Label>

.aspx.cs文件内容

using System;
using System.Data;

using NetOA.Penson;

//主要代码：

        string _gid = function.getRequest("gid");
        string _GroupTree = string.Empty;
        string _sql = "";

        SqlConnection conn = SqlHelper.dbconn();
        conn.Open();
        _sql = "select * from DyjGroup";
        DataTable dt = SqlHelper.ExecuteProDataTable(conn, CommandType.Text, _sql, null);
        Penson ps = new Penson();
        ps.datatable = dt;
        ps.gid = 0;
        ps.groupid =Convert.ToInt32(_gid);
        _GroupTree = "<select name=GroupId id=GroupId>";
        _GroupTree += ps.Trees;
        _GroupTree += "</select>";
        GroupIdlab.Text = _GroupTree;
        dt.Clear();
        dt.Dispose();
        this.JobBind("",conn);
        conn.Close();
        conn.Dispose();

Penson类：

namespace NetOA.Penson
{
    /// <summary>
    /// Penson 的摘要说明
    /// </summary>
    public class Penson
    {
        private string _Trees;
        private static string _TreeList;   //静态数据
        private DataTable _dt;
        private int _gid;
        private int _groupid;

        /// <summary>
        /// 数据结果
        /// </summary>
        public string Trees
        {
            get
            {
                _Trees = this.Tree(_dt, _gid);
                _TreeList = string.Empty;
                return _Trees;
            }
            set
            {
                _Trees = value;
            }
        }

        /// <summary>
        /// Datatable内存表
        /// </summary>
        public DataTable datatable
        {
            get
            {
                return _dt;
            }
            set
            {
                _dt = value;
            }
        }

        /// <summary>
        /// 父编号
        /// </summary>
        public int gid
        {
            get
            {
                return _gid;
            }
            set
            {
                _gid = value;
            }
        }

        /// <summary>
        /// 组编号
        /// </summary>
        public int groupid
        {
            get
            {
                return _groupid;
            }
            set
            {
                _groupid = value;
            }
        }

        #region 数据绑定
        private string Tree(DataTable dt, int _gid)
        {
            string _Select = string.Empty;
            string _toGroupName = string.Empty;
            int _togid = 0;
            int _tolayer = 0;

            DataRow[] _TreeDr = dt.Select("[parent]=" + _gid);
            for (int i = 0; i < _TreeDr.Length; i++)
            {
                _toGroupName = _TreeDr[i]["GroupName"].ToString();
                _togid = (int)_TreeDr[i]["GroupId"];
                _tolayer = (int)_TreeDr[i]["layer"];   //下一层

                if (_togid == _groupid)
                    _Select = "selected='selected'";
                else
                    _Select = "";

                //是否有下级
                if (dt.Select("[parent]=" + _togid).Length > 0)
                {
                    _TreeList += "<option value='" + _togid + "' "+_Select+">" + MakeFelgefu(_tolayer) + _toGroupName + "</option>";
                    Tree(dt, _togid);
                }
                else
                {
                    //j++;
                    _TreeList += "<option value='" + _togid + "' " + _Select + ">" + MakeFelgefu(_tolayer) + _toGroupName+ "</option>";
                }
               
            }

            return _TreeList;
        }

        #endregion 数据绑定

        /// <summary>
        /// Make分隔符
        /// </summary>
        /// <param name="count"></param>
        /// <returns></returns>
        private string MakeFelgefu(int count)
        {
            string Returnwords = string.Empty;
            if (count == 0)
            {
                Returnwords = "";
            }

            else
            {
                Returnwords = ("├").PadLeft(count, '　');
            }
            return Returnwords;
        }

    }
}