C#

<br />
Class B : A<br />
{<br />
public B(int x) : base(x) {}<br />
}<br />

<br />
private void AddDirectory(DirectoryInfo dir, TreeNodeCollection col)<br />
{<br />
	TreeNode node = col.Add(dir.Name);<br />
	try <br />
	{<br />
		foreach(DirectoryInfo x in dir.GetDirectories())<br />
			AddDirectory(x, node.Nodes);<br />
	} <br />
	catch {}<br />
}<br />

<br />
private void AddParent(string dir) <br />
{<br />
	DirectoryInfo dirInfo = new DirectoryInfo(dir);<br />
	TreeNode node = _tree.Nodes.Add(dirInfo.Name);<br />
	node.Tag = dirInfo;<br />
	GetDirectories(dirInfo, node.Nodes);<br />
}<br />
<br />
private void GetDirectories(DirectoryInfo dir, TreeNodeCollection col) <br />
{<br />
	try <br />
	{<br />
		foreach(DirectoryInfo x in dir.GetDirectories())<br />
		{<br />
			TreeNode node = col.Add(x.Name);<br />
			node.Tag = x;<br />
		}<br />
	} <br />
	catch {}<br />
}<br />
<br />
private void Tree_AfterExpand(object sender, System.Windows.Forms.TreeViewEventArgs e)<br />
{<br />
	foreach (TreeNode node in e.Node.Nodes)<br />
		GetDirectories((DirectoryInfo)node.Tag, node.Nodes);<br />
}<br />

private void Form1_Load(object sender, System.EventArgs e)
{
  AddDirectories(_Directory.Nodes, new DirectoryInfo("c:\\"), 1);
}

private void AddDirectories(TreeNodeCollection tn, DirectoryInfo dir, int level)
{
  if (level <= 5)
  {
    try 
    {
      DirectoryInfo[] dirs = dir.GetDirectories();
      foreach(DirectoryInfo subDir in dirs)
      {
        TreeNode newNode = tn.Add(x.ToString());
	newNode.Tag = subDir;
	AddDirectories(newNode.Nodes, subDir, level + 1);
      }
    }
    catch
    {
      // You may want to do something here if an error occurs
    }
  }
}