No hay caso...
De nuevo el codigo completo a ver si alguien me puede ayudar...
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace = "System.Web.Ui.WebControls.ListControl" %>
<%@ Import Namespace = "System.Data" %>
<%@ Import Namespace="System.Data.OleDb" %>
<html>
<head>
<script runat="server">
Dim MyConnection As OleDbConnection
protected withevents MySelect as System.Web.Ui.WebControls.ListBox
Sub Page_Load(ByVal Sender As Object, ByVal E As EventArgs)
'
'Inherits ListControl
'Implements IPostBackDataHandler
'protected withevents MyList1 as System.Web.Ui.WebControls.ListControl
MyConnection = New OleDbConnection("PROVIDER=MICROSOFT.JET.OLEDB.4.0; DATA SOURCE=" & Server.MapPath("../yugh/vggrd.mdb"))
If Not (IsPostBack) Then
Dim DS As DataSet
Dim MyCommand As OleDbDataAdapter
MyCommand = New OleDbDataAdapter("select distinct variedad from vinos", MyConnection)
DS = New DataSet()
MyCommand.Fill(DS, "vinos")
MySelect.DataTextField = "Variedad"
MySelect.DataValueField = "Variedad"
MySelect.DataSource = DS.Tables("vinos").DefaultView
MySelect.DataBind()
End If
End Sub
Protected Sub MySelect_SelectedIndexChanged(ByVal sender _
As System.Object, ByVal e As System.EventArgs) _
Handles MySelect.SelectedIndexChanged
Dim variedad As String
variedad = MySelect.SelectedItem.Text
Dim SelectCmd As String = "select * from vinos where variedad=@variedad"
Dim DS As DataSet
Dim MyCommand As OleDbDataAdapter
MyCommand = New OleDbDataAdapter(SelectCmd, MyConnection)
MyCommand.SelectCommand.Parameters.Add(New OleDbParameter("@Variedad", SqlDbType.VarChar))
MyCommand.SelectCommand.Parameters("@Variedad").Va lue = MySelect.SelectedValue
DS = New DataSet()
MyCommand.Fill(DS, "vinos")
MyList1.DataTextField = "Cepa"
MyList1.DataValueField = "Cepa"
MyList1.DataSource = DS.Tables("vinos").DefaultView
MyList1.DataBind()
End Sub
</script>
</head>
<body>
<form runat="server">
<h3>ListBox AutoPostBack Example</h3>
Select an item from the list box: <br><br>
<asp:ListBox id="MySelect"
DataValueField="Variedad"
Rows="4"
Width = "200"
height = "300"
AutoPostBack="True"
SelectionMode="Single"
runat="server"/>
<asp:ListBox id="MyList1"
DataValueField="Cepa"
Rows="4"
Width = "200"
height = "300"
AutoPostBack="True"
SelectionMode="Single"
runat="server"/>
</form>
</body>
</html>
Para ver el error que esta enviando:
http://www.wineup.cl/wineup/ejemplo6.aspx