程序代码：

        /// <summary>
        /// 递归实现加载目录
        /// </summary>
        /// <param name="ParentNode"></param>
        private void EnumDirectories(TreeNode ParentNode)
        {
            treeView1.SelectedNode = ParentNode;
            string DirectoryPath = ParentNode.Tag.ToString( );
            if(ParentNode.Nodes.Count == 0 )
            {
                if(DirectoryPath.Substring(DirectoryPath.Length-1) != @"\")
                    DirectoryPath += @"\";
                try
                {
                    foreach(string directory in Directory.GetDirectories(DirectoryPath))
                    {
                        TreeNode TempNode = new TreeNode( );
                        TempNode.Text = directory.Substring(directory.LastIndexOf(@"\") + 1 );
                        TempNode.Tag = directory;
                        TempNode.ImageIndex = 3;
                        TempNode.SelectedImageIndex = 2;
                        treeView1.SelectedNode.Nodes.Add(TempNode);
                        treeView1.SelectedNode.Nodes[treeView1.SelectedNode.Nodes.Count-1].EnsureVisible( );
                    }
                }
                catch(Exception)
                {
                }
            }
        }