带线的无限级下拉树列表

好多年没写文章了
这里就分享点自己原创的一点破代码,效果如图下:

本人的提供的代码如下:

using System;
using System.Collections.Generic;
using System.Text;
using System.Web.UI.WebControls;

namespace Interface.Common
{
    public interface IDropDownTree : IDisposable
    {
        /**////  summary
        /// 返回Dictionary里分别对应ID,文本,如果没有子节点返回null
        ///  /summary
        ///  param name="parentID" 父节点ID /param
        ///  returns /returns
        Dictionary string, string  GetChildCategory(string parentID);
        /**////  summary
        /// 代码里写return new Interface.Common.DropDownTree(this);
        ///  /summary
        DropDownTree DropDownTree
        {
            get;
        }
    }
    public sealed class DropDownTree
    {
        IDropDownTree _DropDownTree;
        public DropDownTree(IDropDownTree dropDownTree)
        {
            _DropDownTree = dropDownTree;
        }
        /**////  summary
        /// 用于树的前缀
        ///  /summary
        ///  param name="IsLast" 是否是同级节点中的最后一个 /param
        ///  param name="HasChild" 本节点是否拥有子节点 /param
        ///  param name="ParentString" 父节点前缀符号 /param
        ///  returns 本节点的前缀 /returns
        private string GetPreFix(bool isLast, bool hasChild, string parentString)
        {
            string result = string.Empty;
            if (!string.IsNullOrEmpty(parentString))
            {
                parentString = parentString.Remove(parentString.Length - 1).Replace("├", "│").Replace("└", " ");
                result += parentString;
            }
            if (isLast)
            {
                result += "└";
            }
            else
            {
                result += "├";
            }
            if (hasChild)
            {
                result += "┬";
            }
            else
            {
                result += "─";
            }
            return result;
        }
        绑定下拉菜单#region 绑定下拉菜单

        /**////  summary
        /// 绑定连动级的下拉菜单
        ///  /summary
        ///  param name="ddlGoodsType" 传进一个被绑定的DropDownList /param
        ///  param name="removeID" 被排除绑定的节点ID /param
        ///  param name="AutoDispose" 是否自动释放 /param
        public void BindToDropDownList(DropDownList ddlGoodsType, string removeID,string parentID, bool autoDispose)
        {
            if (ddlGoodsType != null)
            {
                ListItem listItem = null;
                string currentID = parentID;//根节点/父ID
                string currentSign = string.Empty;//当前节点符号;
                string parrentSign = string.Empty; //父节点符号;
                bool HasChild = true;//是否有子
                Queue string  parentKeyList = new Queue string //存 有子节点的 节点ID
                Queue string  parentSignList = new Queue string //对应节点ID的前缀符号
                int itemIndexOf = 0;//父节点所在的位置
                while (HasChild)
                {
                    int lastOneCount = 1;//用于计算在同级别中是否最后一个
                    Dictionary string, string  childList = _DropDownTree.GetChildCategory(currentID);// 得到子节点列表
                    if (childList != null   childList.Count   0)
                    {
                        if (!string.IsNullOrEmpty(removeID)   childList.ContainsKey(removeID))
                        {
                            childList.Remove(removeID);
                        }
                        foreach (KeyValuePair string, string  entry in childList)
                        {
                            if (_DropDownTree.GetChildCategory(entry.Key) != null)//存在子
                            {
                                currentSign = GetPreFix(lastOneCount == childList.Count, true, parrentSign);
                                listItem = new ListItem(currentSign + entry.Value, entry.Key);

                                parentKeyList.Enqueue(entry.Key);//当前的节点ID
                                parentSignList.Enqueue(currentSign);//当前的节点符号
                            }
                            else//不存在子
                            {
                                currentSign = GetPreFix(lastOneCount == childList.Count, false, parrentSign);
                                listItem = new ListItem(currentSign + entry.Value, entry.Key);
                            }
                            if (ddlGoodsType.Items.Count != 0)
                            {
                                itemIndexOf = string.IsNullOrEmpty(currentID) ? itemIndexOf + 1 : ddlGoodsType.Items.IndexOf(ddlGoodsType.Items.FindByValue(currentID)) + lastOneCount;
                            }
                            ddlGoodsType.Items.Insert(itemIndexOf, listItem);//添加子节点
                            lastOneCount++;
                        }
                        if (parentKeyList.Count   0)//存在子节点时
                        {
                            currentID = parentKeyList.Dequeue();
                            parrentSign = parentSignList.Dequeue();
                        }
                        else
                        {
                            HasChild = false;
                        }
                    }
                    else
                    {
                        break;
                    }


                }
                if (autoDispose)
                {
                    _DropDownTree.Dispose();
                }

            }
        }
        /**////  summary
        /// 绑定连动级的下拉菜单
        ///  /summary
        ///  param name="ddlGoodsType" 传进一个被绑定的DropDownList /param
        public void BindToDropDownList(DropDownList ddlGoodsType)
        {
            BindToDropDownList(ddlGoodsType, string.Empty,null, true);
        }
        /**////  summary
        /// 绑定连动级的下拉菜单
        ///  /summary
        ///  param name="ddlGoodsType" 传进一个被绑定的DropDownList /param
        ///  param name="removeID" 被排除的ID /param
        public void BindToDropDownList(DropDownList ddlGoodsType, string removeID)
        {
            BindToDropDownList(ddlGoodsType, removeID,null, true);
        }
        /**////  summary
        /// 绑定连动级的下拉菜单
        ///  /summary
        ///  param name="ddlGoodsType" 传进一个被绑定的DropDownList /param
        ///  param name="removeID" 被排除的ID,若没有,传null /param
        ///  param name="parentID" 起始父ID /param
        public void BindToDropDownList(DropDownList ddlGoodsType, string removeID,string parentID)
        {
            BindToDropDownList(ddlGoodsType, removeID,parentID, true);
        }
        #endregion
    }
}

调用方法很简单:
1.继承自IDropDownTree接口
2.实现3个接口方法

实现接口代码示例[Dispose方法自己实现],最主要的是自己实现获得子级的方法
 IDropDownTree 成员#region IDropDownTree 成员

        public Dictionary string, string  GetChildCategory(string parentID)
        {
            string where = "ParentID=" + parentID + "";
            if (string.IsNullOrEmpty(parentID))
            {
                where = "ParentID is null or ParentID=" + Guid.Empty + "";
            }
            List GoodsCategoryBean  _GoodsCategoryList = SelectList(0, where, string.Empty, false);
            if (_GoodsCategoryList != null   _GoodsCategoryList.Count   0)
            {
                Dictionary string, string  categoryList = new Dictionary string, string
                for (int i = 0; i   _GoodsCategoryList.Count; i++)
                {
                    categoryList.Add(_GoodsCategoryList[i].ID.ToString(), _GoodsCategoryList[i].GategoryName);
                }
                return categoryList;
            }
            return null;
        }

        public Interface.Common.DropDownTree DropDownTree
        {
            get { return new Interface.Common.DropDownTree(this); }
        }

        #endregion 页面调用代码: 类名.DropDownTree.BindToDropDownList(下拉控件ID);

希望对大伙有点帮助....
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