Function
#Region "drop-down frame tree bind" private function DDLBIND (Byval DDL AS DROPDOWNLIST, BYVAL DT AS DATATABLE) DIM FATHERID AS STRING IF DT.ROWS.COUNT = 0 THEN EXIT FUNCTION DIM I as INTEGER = DT.ROWS.COUNT - 1 me.textbox1.text = me.textbox1.text 1 Dim n as integer = me.textbox1.text Dim J AS Integer While I 1> 0 if Isdbnull (Dt.Rows (i) .Item ("DC_Parent_ID") ) THEN FATHERID = "" Else FatherId = dt.rows (i) .Item ("DC_PARENT_ID") End IF
DIM STRPADING As String = "" "
If DDL.Items (n) .Value = Fatherid Then for j = 0 to n strpading = "" "" NEXT
Dim Rslist as new listitem rslist.text = strpading & "├" & dt.rows (i) .Item ("dc_name") rslist.value = dt.rows (i) .Item ("DC_ID") DDL.Items.add (RSLIST)
Dt.ROWS (i) .delete () Dt.acceptchanges ()
DDLBIND (DDL, DT)
i = dt.rows.count end if i = i - 1 end while end function # End Region
2. Application
1) Place a TextBox control on the page, id = "textbox1", text = -1
2) Direct call function
