Hi,
I have 2 listboxes. The first gets populated from the db as soon as
the page loads. The second listbox get populated based on the user's
selection from the first listbox. However, currently the code is
such that with each selection there is a postback. We want to avoid it
using filter and javascript. I am not using ADO.NET but adodbc and no
datagrids or datasets (please don't tell me that i should as my boss
clearly doesn't want to get into it at this stage).
How can i do it?
Thanks
Currently the code with the postback is as follows:
page_load
if not page.ispostback then
Do While Not rs.EOF
li = New ListItem(rs("cat_name").Value,
rs("cat_id").Value)
List1.Items.Add(li)
rs.MoveNext()
Loop
End If
'List1.SelectedIndex = 0
rs.Close()
rs = Nothing
List1.SelectedValue = cat_id
'here there is some other code not relevant to the
listboxes
'select items for second listbox
Dim rsSub As New ADODB.Recordset
rsSub.Open("SELECT sub_name, sub_id FROM subs WHERE
cat_id=" & cat_id.ToString & " ORDER BY sub_name ASC", cn)
Dim l_item As ListItem
Do While Not rsSub.EOF
l_item = New ListItem(rsSub("sub_name").Value,
rsSub("sub_id").Value)
List2.Items.Add(l_item)
rsSub.MoveNext()
Loop
List2.SelectedValue = sub_id
rsSub.Close()
rsSub = Nothing
cn.Close()
End If
' End If
End If
End Sub
Protected Sub Select1Change(ByVal sender As System.Object, ByVal e
As System.EventArgs)
Dim cn As New ADODB.Connection
cn.Open(YBayTools.Constants.ConnectionString)
Dim rs As New ADODB.Recordset
Dim li As ListItem
rs.Open("Select * from subs where cat_ID =" &
List1.SelectedItem.Value.ToString, cn)
'rs.Open("Select * from subs where cat_ID ='" &
List1.SelectedItem.Text.ToString & "' &
List1.SelectedItem.value.ToString", cn)
Dim strCat As String
If List2.Items.Count > 0 Then
List2.Items.Clear()
End If
If rs.BOF And rs.EOF Then
Response.Write("no records found")
Else
Do While Not rs.EOF
li = New ListItem(rs("sub_name").Value,
rs("sub_id").Value)
List2.Items.Add(li)
rs.MoveNext()
Loop
End If
rs.Close()
rs = Nothing
cn.Close()
