.net2005中TreeView数据绑定

private void Bind()
    ...{
       
       SqlDataAdapter da = new SqlDataAdapter("select distinct(ParentTitle) from Test", cn);
       DataSet ds = new DataSet();
            da.Fill(ds, "cate");
            TreeNode catenode;
            TreeNode pronode;
            foreach (DataRow caterow in ds.Tables[0].Rows)
            ...{
                catenode = new TreeNode();
                catenode.Text = caterow["ParentTitle"].ToString();
                catenode.Value = caterow["ParentTitle"].ToString();
                TreeView1.Nodes.Add(catenode);
                string StrSql = "select SubTitle from Test where ParentTitle='" + catenode.Value + "'";
                SqlDataAdapter proda = new SqlDataAdapter(StrSql, cn);
                proda.Fill(ds, "pro");
                if (ds.Tables["pro"].Rows.Count > 0)
                ...{
                    foreach (DataRow prorow in ds.Tables["pro"].Rows)
                    ...{
                        pronode = new TreeNode();
                        pronode.Text = prorow["SubTitle"].ToString();
                        pronode.NavigateUrl = "Test.aspx?id=" + prorow["SubTitle"].ToString();
                        pronode.Value = prorow["SubTitle"].ToString();
                        catenode.ChildNodes.Add(pronode);
                    }
                    ds.Tables["pro"].Clear();
                }
            }


    }