读取access数据库，绑定treeview的问题。

在网上百度的代码自己改了下。显示不出来。实在是菜鸟 麻烦大家帮忙看看吧。谢谢
附上代码
 public void BindTree(TreeView tview, TreeNode tn_main, string First_ID, string sql)
    {
        string ConnectionStr = "PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA Source=" + Server.MapPath(System.Configuration.ConfigurationManager.AppSettings["ConnectionStr"].ToString());//从Web.config文件中获取数据库连接字符串
        OleDbConnection AccessConnection = new OleDbConnection(ConnectionStr);
        AccessConnection.Open();//打开数据库
        string sql1 = "select Role from Fun_First ";
        OleDbCommand AccessCommand = new OleDbCommand(sql1,AccessConnection);
        OleDbDataReader AccessReader = AccessCommand.ExecuteReader();
        OleDbDataAdapter adapter = new OleDbDataAdapter(sql1,AccessConnection);
        DataSet DS = new DataSet();
        adapter.Fill(DS,"Fun_First");        TreeNode tn = null;
        tview.Font.Size = FontUnit.Small;
        tview.ForeColor = System.Drawing.Color.Black;
        DataTable dTable = DS.Tables[0];
        DataRow[] drows = dTable.Select(" First_ID='" + First_ID + "'");        foreach (DataRow drow in drows)
        {
            tn = new TreeNode();
            tn.Text = drow["modulName"].ToString();
            tn.Value = drow["modulId"].ToString();
            tn.SelectAction = TreeNodeSelectAction.Expand;
            tn.NavigateUrl = "MAIN.aspx";
            tn.Expanded = true;
            if (tn_main == null)
            {
                tview.Nodes.Add(tn);
            }
            else
            {
                tn_main.ChildNodes.Add(tn);
            }
            DataSet DST = new DataSet();
            adapter.Fill(DST, "TB_User");     
            DataTable DTB = DST.Tables[0];
            DataRow[] dar = DTB.Select(" First_ID='" + tn.Value + "'");
            First_ID = tn.Value;
            BindTree(tview, tn, First_ID, sql);
        }
    }