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

希望本文所述对大家asp.net程序设计有所帮助。