用Asp.net 写的一个通用的Tree using System;using System.Data;using MyOA.DataAccessLayer;namespace MyOA.CommonComponent...{ /**//// <summary> /// 一个通用的树状菜单类 /// </summary> public class Tree ...{ private string _treeHtml; private DataTable _dataTable; /**//// <summary> /// 根据DataTable对象,生成一棵树 /// </summary> /// <param name="dataTable">树中节点的数据</param> /// <returns>树的HTML代码</returns> public string CreateTree(DataTable dataTable) ...{ this._dataTable=dataTable; this.CreateSubTree(0); return _treeHtml; } /**//// <summary> /// 获取父节点编号为parentId的所有节点,并用DataTable返回 /// </summary> /// <param name="parentId">父节点编号</param> /// <returns>DataTable形式的所有孩子节点数据</returns> private DataTable GetChilds(int parentId) ...{ DataTable childNodes=new DataTable(); childNodes=this._dataTable.Clone(); foreach(DataRow dr in this._dataTable.Rows) ...{ if(Convert.ToInt32(dr["ParentId"])==parentId) ...{ childNodes.ImportRow(dr); } } return childNodes; } /**//// <summary> /// 判断编号为nodeId的节点是否为叶子节点 /// </summary> /// <param name="nodeId">待判断的节点编号</param> /// <returns>是叶子节点:返回true;否则:返回false</returns> private bool IsLeaf(int nodeId) ...{ foreach(DataRow dr in this._dataTable.Rows) if(Convert.ToInt32(dr["ParentId"])==nodeId) return false; return true; } /**//// <summary> /// 得到编号为nodeId的节点的父节点编号 /// </summary> /// <param name="nodeId">节点编号</param> /// <returns>父节点编号</returns> private int GetParent(int nodeId) ...{ foreach(DataRow dr in this._dataTable.Rows) if(Convert.ToInt32(dr["NodeId"])==nodeId) return Convert.ToInt32(dr["ParentId"]); return -1; } /**//// <summary> /// 得到编号为nodeId的节点的级别,根节点为0 /// </summary> /// <param name="nodeId">待计算的巨额电编号</param> /// <returns>节点的级别,根节点为0</returns> private int GetLevel(int nodeId) ...{ int parentId=GetParent(nodeId); if(parentId==0) return 1; else return GetLevel(parentId)+1; //递归 } /**//// <summary> /// 递归生成根编号为nodeId的树 /// </summary> /// <param name="nodeId">所要生成子树的根节点</param> private void CreateSubTree(int nodeId) ...{ DataTable childNodes=this.GetChilds(nodeId); //获取根节点的所有孩子 //循环生成根节点的所有孩子对应的HTML int childId=0; foreach(DataRow dr in childNodes.Rows) ...{ childId=Convert.ToInt32 (dr["nodeId"]); this._treeHtml+="<div id=div_"+childId.ToString()+">"; //根据该孩子的级别,生成一些空格,以体现层次结构 for(int i=0;i<GetLevel(childId);i++) this._treeHtml+=" "; //如果该孩子是叶子节点,则生成其HTML代码 if(this.IsLeaf(childId)) ...{ this._treeHtml+="<img src='./Images/folder.gif'/><a href="+dr["Url"]+">"+dr["Text"]+"</a></div>"; } //如果该孩子为中间节点,则首先构造其HTML,然后递归生成其所有孩子的HTML else ...{ this._treeHtml+="<img src='./Images/folderopen.gif'/><a href="+dr["Url"]+">"+dr["Text"]+"</a></div>"; this.CreateSubTree(childId);//递归 } } } }}