Directory Picker in C#

protected void PopulateNode(TreeNode aNode)
{
this.Cursor = Cursors.WaitCursor; // Set up the wait cursor
string strDir = BuildDirectory(aNode); // Build the directory tree string from the tree node
Directory Dir = new Directory(strDir); // Use the Directory class to get the files and directory names in the directory
int count = 0;
// Get each directory name and add it as a directory folder tree node
for (int i = 0; i < Dir.GetDirectories().Length; i++)
{
TreeNode ChildNode = new TreeNode(Dir.GetDirectories()[i].Name, 1,0);
aNode.Nodes.Add(i, ChildNode);
count++;
}
// Get each file name and add it as a file tree node
for (int i = 0; i < Dir.GetFiles(m_strFilter).Length; i++)
{
TreeNode ChildNode = new TreeNode(Dir.GetFiles(m_strFilter)[i].Name, 2,2);
aNode.Nodes.Add(i+count, ChildNode);
}
aNode.Expand(); // show the children nodes
this.Cursor = Cursors.Arrow; // restore the cursor
}

protected string BuildDirectory(TreeNode aNode)
{
TreeNode theNode = aNode;
string strDir = "";
// Cycle through the node and all its parents to build the full path of the directory
while (theNode != null)
{
if (theNode.Text[theNode.Text.Length - 1] != '\\')
{
strDir = "\\" + strDir;
}
strDir = theNode.Text + strDir;
theNode = theNode.Parent;
}
return strDir;
}

public void treeView1_AfterSelect (object sender, System.WinForms.TreeViewEventArgs e)
{
// check to see if the selected node is already populated
if (e.node.Nodes.Count > 0 || e.node.ImageIndex == 2)
{
return;
}
// The node is not populated, so populate the selected node
PopulateNode(e.node);
}

protected void button1_Click (object sender, System.EventArgs e)
{
label3.Text = dirTree1.Path;
label4.Text = dirTree1.FileName;
}