treeview的建立

    protected void Page_Load(object sender, EventArgs e)
    {
        bindtree(this.TreeView1.Nodes,-1);
    }

    public void bindtree(TreeNodeCollection nds, int parentId)
    {
        TreeNode tn = null;
        DataSet ds = objdb.dropbind(" config_ca_area where parent_id=" + parentId);
        DataView dv = ds.Tables[0].DefaultView;
        foreach (DataRowView dr in dv)
        {
            tn = new TreeNode(dr["area_name"].ToString(), dr["area_id"].ToString());
            //tn.ShowCheckBox = true;

            nds.Add(tn);

            bindtree(tn.ChildNodes, Convert.ToInt32(dr["area_id"]));
        }
    }