I have created a web page (using web matrix) that contains a listbox (of city names) that is bound to a datatable. I then want to be able to pre-select a city name as the default (see code below).
It appears that the databind() function does not fully let go of the listbox control on page_load(). Even when I place my selection code in page_prerender(), I am unable to default to the city name.
As a test, I manually loaded the listbox and the code worked fine and I was able to default to the city name.
Any ideas?
Thank you in advance.
<%@ Page Language="
VB" smartnavigation="True" autoeventwireup="False" Inherits="System.Web.UI.Page" %>
<%@ import Namespace="System" %>
<%@ import Namespace="System.Web.UI" %>
<%@ import Namespace="System.Web.UI.Page" %>
<%@ import Namespace="System.Web.UI.WebControls" %>
<%@ import Namespace="System.Data" %>
<%@ import Namespace="System.Data.SqlClient" %>
<script runat="server">
Dim adoDtCity As New DataTable
Public Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'// Load listbox with static values
'lstCity.Items.Add(New ListItem("Amlin", 1))
'lstCity.Items.Add(New ListItem("Bexley", 2))
'lstCity.Items.Add(New ListItem("Blacklick", 3))
'lstCity.Items.Add(New ListItem("Canal Winchester", 4))
'lstCity.Items.Add(New ListItem("Columbus", 5))
'lstCity.Items.Add(New ListItem("Dublin", 6))
'lstCity.Items.Add(New ListItem("Gahanna", 7))
'lstCity.Items.Add(New ListItem("Galloway", 8))
'// Load listbox from database
adoDtCity = GetCityTbl()
lstCity.DataSource = adoDtCity
lstCity.DataTextField = "name"
lstCity.DataBind()
End Sub
Public Sub Page_PreRender(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.PreRender
lstCity.SelectedIndex = lstCity.Items.IndexOf(lstCity.Items.FindByText("Co lumbus"))
End Sub
Public Function GetCityTbl() As DataTable
Dim adoCn As SqlConnection
Dim adoCd As SqlCommand
Dim adoDr As SqlDataReader
Dim adoDt As New DataTable()
Dim adoParm As SqlParameter
Dim adoRow As DataRow
Try
adoDt.Columns.Add("city_id", System.Type.GetType("System.String"))
adoDt.Columns.Add("name", System.Type.GetType("System.String"))
adoCn = New SqlConnection(ConfigurationSettings.AppSettings("S QL_LOGIN"))
adoCd = New SqlCommand(ConfigurationSettings.AppSettings("spAl lCity"), adoCn)
adoCd.CommandType = CommandType.StoredProcedure
adoParm = adoCd.Parameters.Add(New SqlParameter("@PgmID", SqlDbType.VarChar, 4))
adoParm.Direction = ParameterDirection.Input
adoParm.Value = ConfigurationSettings.AppSettings("PGM")
adoCn.Open()
adoDr = adoCd.ExecuteReader(CommandBehavior.CloseConnectio n)
While adoDr.Read
adoRow = adoDt.NewRow()
adoRow(0) = adoDr("city_id")
adoRow(1) = adoDr("name")
adoDt.Rows.Add(adoRow)
End While
Catch
'Error handling goes here
Finally
adoCn.Close()
End Try
Return adoDt
End Function
</script>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<meta content="Microsoft Visual Studio.NET 7.0" name="GENERATOR" />
<meta content="Visual Basic 7.0" name="CODE_LANGUAGE" />
<meta content="JavaScript" name="vs_defaultClientScript" />
<meta content="http://schemas.microsoft.com/intellisense/ie5" name="vs_targetSchema" />
<link href="Includes/cnas.css" rel="stylesheet" />
<script language="javascript" src="Includes/inc_cmn_pg.
js"></script>
</head>
<body>
<form id="Intake" method="post" runat="server">
<div id="contentstart" style="HEIGHT: 100px">
<table cellspacing="0" cellpadding="0" width="760" border="0">
<tbody>
<tr><td> </td></tr>
<tr>
<td>
<asp:ListBox id="lstCity" runat="server" rows="1" Font-Size="Smaller" Font-Names="Arial"></asp:ListBox>
</td>
</tr>
</tbody>
</table>
</div>
<asp:Label id="lblMsg" runat="server"></asp:Label>
</form>
</body>
</html>
Selecting an Item from a databound listbox
Linear Mode
