C # TreeView binding Data "Go"

private void BindTreeView1 () {String sql = "SELECT * from Dm_category"; DataTable dt = db.            Executedatatable (SQL, CommandType.Text, NULL); datarow[] dr = dt.            Select ("parent_id is null"); for (int i = 0; i < Dr. Length;                i++) {TreeNode tn = new TreeNode (); Tn. Text = dr[i]["Category_name"].                ToString (); Tn. Tag = dr[i]["id"].                    ToString ();                Filltree (TN, DT);            TreeView1.Nodes.Add (TN); }} private void Filltree (TreeNode node, DataTable DT) {datarow[] DRR = dt. Select ("Parent_id=" + node.            Tag.tostring () + "'"); if (DRR. Length > 0) {for (int i = 0; i < DRR. Length;                    i++) {TreeNode TNN = new TreeNode (); Tnn. Text = drr[i]["Category_name"].                    ToString (); Tnn. Tag = drr[i]["id"].                    ToString (); If(drr[i]["parent_id"). ToString () = = node.                    Tag.tostring ()) {Filltree (TNN, DT); } node.                Nodes.Add (TNN); }            }        }

　　

C # TreeView binding Data "Go"