asp.net TreeView遞歸循環子節點生成樹形菜單實例

/// <summary>
/// 生成根節點
/// </summary>
/// <param name="treeview"></param>
protected void BindTreeView(long ID, TreeView treeview)
{
 DataTable dt = menuLogic.GetMenu2(ID, User.Identity.Name);
 treeview.Nodes.Clear();
 DataRow[] parentrow = dt.Select("par_id=0");
 for (int i = 0; i < parentrow.Length; i++)
 {
 TreeNode rootnode = new TreeNode();
 rootnode.Text = parentrow[i]["node_name"].ToString(); //parentrow[i][3].ToString();
 rootnode.Value = parentrow[i]["ID"].ToString(); //parentrow[i][1].ToString(); 主鍵
 rootnode.Expanded = true;
 rootnode.Selected = false;
 rootnode.SelectAction = TreeNodeSelectAction.None;
 treeview.Nodes.Add(rootnode);
 CreateChildNode(rootnode, dt); //
 }
}
/// <summary>
/// 生成子節點
/// </summary>
/// <param name="parentNode"></param>
/// <param name="datatable"></param>
protected void CreateChildNode(TreeNode parentNode, DataTable datatable)
{
 DataRow[] rowlist = datatable.Select("par_id=" + parentNode.Value);
 for (int i = 0; i < rowlist.Length; i++)
 {
 TreeNode node = new TreeNode();
 if (datatable.Select("par_id=" + rowlist[i]["ID"].ToString().Trim()).Length > 0)
 {
 node.Text = rowlist[i]["node_name"].ToString();
 node.Value = rowlist[i]["ID"].ToString();
 }
 else
 {
 node.Text = "<a href=\"javascript:;\" onclick=\"OpenUrl('" + rowlist[i]["url"].ToString().Trim() + "',this)\">" + rowlist[i]["node_name"].ToString() + "</a>";
 node.Value = rowlist[i]["ID"].ToString();
 }
 node.Expanded = false;
 node.Selected = false;
 node.SelectAction = TreeNodeSelectAction.None;
 parentNode.ChildNodes.Add(node);
 CreateChildNode(node, datatable); //遞歸調用
 }
}