本文实例讲述了asp.net实现DropDownList,TreeView,ListBox的无限极分类目录树。分享给大家供大家参考，具体如下：

#region DropDownList无限递归显示层次关系
/// <summary>
/// 创建无限分级下拉列表框
/// </summary>
/// <param name="ddlst">下拉控件</param>
/// <param name="dt">源DataTable</param>
/// <param name="text">text字段</param>
/// <param name="value">value字段</param>
/// <param name="parentid">深度字段 例如parentid</param>
public static void CreateLevelDropDown(DropDownList ddlst, DataTable dt, string text, string value, string parentid)
{
 ArrayList allItems = new ArrayList();
 DataRow[] rows = dt.Select(parentid + "=0");
 foreach (DataRow row in rows)
 CreateLevelDropDownAssistant(dt, ref allItems, row, string.Empty, text, value, parentid);
 ListItem[] items = new ListItem[allItems.Count];
 allItems.CopyTo(items);
 ddlst.Items.AddRange(items);
}
/// <summary>
/// 递归绑定子节点
/// </summary>
/// <param name="dt">源DataTable</param>
/// <param name="items">数组</param>
/// <param name="parentRow">当前节点</param>
/// <param name="curHeader">前缀</param>
/// <param name="text">text字段</param>
/// <param name="value">value字段</param>
/// <param name="parentid">深度字段 例如parentid</param>
private static void CreateLevelDropDownAssistant(DataTable dt, ref ArrayList items, DataRow parentRow, string curHeader, string text, string value, string parentid)
{
 ListItem newItem = new ListItem(curHeader + Until.CutString(parentRow[text].ToString(), 18, true), parentRow[value].ToString());
 items.Add(newItem);
 DataRow[] rows = dt.Select(parentid + "=" + newItem.Value);
 for (int i = 0; i < rows.Length - 1; i++)
 CreateLevelDropDownAssistant(dt, ref items, rows[i], curHeader.Replace("┣", "┃").Replace("┗", "┣") + "┣", text, value, parentid);
 if (rows.Length > 0)
 CreateLevelDropDownAssistant(dt, ref items, rows[rows.Length - 1], curHeader.Replace("┣", "┃").Replace("┗", "┣") + "┗", text, value, parentid);
}
#endregion
#region TreeView 无限递归显示层次关系目录树
/// <summary>
/// 创建无限分级目录树TreeView
/// </summary>
/// <param name="treeview">TreeView空间</param>
/// <param name="dt">数据源DataTable</param>
/// <param name="text">text字段</param>
/// <param name="value">value字段</param>
/// <param name="parentid">深度字段 例如parentid</param>
public static void CreateLevelTreeView(TreeView treeview, DataTable dt, string text, string value, string parentid)
{
 DataView dv = dt.DefaultView;
 dv.RowFilter = parentid + "=0";
 foreach (DataRowView drv in dv)
 {
 TreeNode node = new TreeNode();
 node.Text = drv[text].ToString();
 node.Value = drv[value].ToString();
 node.Expanded = false;
 treeview.Nodes.Add(node);
 CreatTreeViewChildNode(dv, node, text, value, parentid);
 }
}
/// <summary>
/// 递归绑定子节点
/// </summary>
/// <param name="dv">源DataView</param>
/// <param name="parentNode">当前节点</param>
/// <param name="text">text字段</param>
/// <param name="value">value字段</param>
/// <param name="parentid">深度字段 例如parentid</param>
private static void CreatTreeViewChildNode(DataView dv, TreeNode parentNode, string text, string value, string parentid)
{
 dv.RowFilter = parentid + "=" + parentNode.Value;
 foreach (DataRowView row in dv)
 {
 TreeNode replyNode = new TreeNode();
 replyNode.Text = row[text].ToString();
 replyNode.Value = row[value].ToString();
 replyNode.Expanded = false;
 parentNode.ChildNodes.Add(replyNode);
 CreatTreeViewChildNode(dv, replyNode, text, value, parentid);
 }
}
/// <summary>
/// 创建无限分级目录树TreeView
/// </summary>
/// <param name="treeview">TreeView空间</param>
/// <param name="dt">数据源DataTable</param>
/// <param name="text">text字段</param>
/// <param name="value">value字段</param>
/// <param name="url">url字段</param>
/// <param name="parentid">深度字段 例如parentid</param>
public static void CreateLevelTreeView(TreeView treeview, DataTable dt, string text, string value, string url, string parentid)
{
 DataView dv = dt.DefaultView;
 dv.RowFilter = parentid + "=0";
 foreach (DataRowView drv in dv)
 {
 TreeNode node = new TreeNode();
 node.Text = drv[text].ToString();
 node.Value = drv[value].ToString();
 node.NavigateUrl = drv[url].ToString();
 node.Expanded = false;
 treeview.Nodes.Add(node);
 CreatTreeViewChildNode(dv, node, text, value, url, parentid);
 }
}
/// <summary>
/// 递归绑定子节点
/// </summary>
/// <param name="dv">源DataView</param>
/// <param name="parentNode">当前节点</param>
/// <param name="text">text字段</param>
/// <param name="value">value字段</param>
/// <param name="url">url字段</param>
/// <param name="parentid">深度字段 例如parentid</param>
private static void CreatTreeViewChildNode(DataView dv, TreeNode parentNode, string text, string value, string url, string parentid)
{
 dv.RowFilter = parentid + "=" + parentNode.Value;
 foreach (DataRowView row in dv)
 {
 TreeNode replyNode = new TreeNode();
 replyNode.Text = row[text].ToString();
 replyNode.Value = row[value].ToString();
 replyNode.NavigateUrl = row[url].ToString();
 replyNode.Expanded = false;
 parentNode.ChildNodes.Add(replyNode);
 CreatTreeViewChildNode(dv, replyNode, text, value, url, parentid);
 }
}
#endregion
#region 创建无限分级ListBox
/// <summary>
/// 创建无限分级ListBox
/// </summary>
/// <param name="ddlst">ListBox控件</param>
/// <param name="dt">源DataTable</param>
/// <param name="text">text字段</param>
/// <param name="value">value字段</param>
/// <param name="parentid">深度字段 例如parentid</param>
public static void CreateLevelListBox(ListBox ddlst, DataTable dt, string text, string value, string parentid)
{
 ArrayList allItems = new ArrayList();
 DataRow[] rows = dt.Select(parentid + "=0");
 foreach (DataRow row in rows)
 CreateLevelListBoxAssistant(dt, ref allItems, row, string.Empty, text, value, parentid);
 ListItem[] items = new ListItem[allItems.Count];
 allItems.CopyTo(items);
 ddlst.Items.AddRange(items);
}
/// <summary>
/// 递归绑定子节点
/// </summary>
/// <param name="dt">源DataTable</param>
/// <param name="items">数组</param>
/// <param name="parentRow">当前节点</param>
/// <param name="curHeader">前缀</param>
/// <param name="text">text字段</param>
/// <param name="value">value字段</param>
/// <param name="parentid">深度字段 例如parentid</param>
private static void CreateLevelListBoxAssistant(DataTable dt, ref ArrayList items, DataRow parentRow, string curHeader, string text, string value, string parentid)
{
 ListItem newItem = new ListItem(curHeader + Until.CutString(parentRow[text].ToString(), 18, true), parentRow[value].ToString());
 items.Add(newItem);
 DataRow[] rows = dt.Select(parentid + "=" + newItem.Value);
 for (int i = 0; i < rows.Length - 1; i++)
 CreateLevelListBoxAssistant(dt, ref items, rows[i], curHeader.Replace("┣", "┃").Replace("┗", "┣") + "┣", text, value, parentid);
 if (rows.Length > 0)
 CreateLevelListBoxAssistant(dt, ref items, rows[rows.Length - 1], curHeader.Replace("┣", "┃").Replace("┗", "┣") + "┗", text, value, parentid);
}
#endregion

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