creating dynamic list

fyeojo · August 18th, 2003, 11:03 AM

in classic asp, iterating through an array or recordset will create the required options for a selection box. e.g.:

<select>
   <%do while not rs.eof%>
      <option value="<%=rs(0)%>"><%=rs(1)%></option>
   <%rs.MoveNext%>
   <%loop%>
</select>

how do i do the same with asp:dropdownlist in aspx file, and my code for dynamic content in a user control ascx file?

wrECKster · August 19th, 2003, 07:15 AM

Page: dropdownlist.ascx (user control)

Code:

<%@ Control Language="vb" AutoEventWireup="false" Codebehind="dropdownlist.ascx.vb" Inherits="dropDownList.dropdownlist" TargetSchema="http://schemas.microsoft.com/intellisense/ie5" %>
<asp:DropDownList id="DropDownList1" runat="server"></asp:DropDownList>

codebehind:

Code:

Imports System.Data.SqlClient

Public Class dropdownlist
    Inherits System.Web.UI.UserControl

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here

        If Not Page.IsPostBack Then
            Binddata()
        End If
    End Sub


    Sub Binddata()

        'create connection using pubs database
        Dim sConn As String = "server=localhost;User Id=sa;Password=password;Initial Catalog=pubs"
        Dim myConn As New SqlConnection(sConn)

        Dim sSQL As String = "SELECT stor_id, stor_name FROM Stores ORDER BY stor_name"

        Dim myCommand As New SqlCommand(sSQL, myConn)

        myConn.Open()

        ' create a datareader
        Dim dr As SqlDataReader
        dr = myCommand.ExecuteReader(CommandBehavior.CloseConnection)

        ' setup the text and value fields for the drop down list
        DropDownList1.DataTextField = "stor_name"
        DropDownList1.DataValueField = "stor_id"

        ' databind the reader to the dropdownlist
        DropDownList1.DataSource = dr
        DropDownList1.DataBind()

    End Sub
End Class

fyeojo · August 19th, 2003, 10:59 PM

thx for responding.

while trying to make it work, i attempted to do it all within the aspx file, but did not succeed. i want to bind my asp:dropdownlist to Session("AllGroups"), a one-dimensional array. here's my code that raised an error:

the html code:

<tr><td>
<asp:label for="selGroups">Select your default group:</asp:label>
<asp:dropdownlist id="selGroups" runat="server">
</asp:dropdownlist></td></tr>

<tr><td style="line-height:20px;"> </td></tr>

<tr><td><asp:label for="selForums">Select your default forum:</asp:label>
<asp:dropdownlist id="selForums" runat="server">
<asp:listitem>Network</asp:listitem>
<asp:listitem>Social</asp:listitem>
</asp:dropdownlist></td></tr>

the runtime binding code is:

<script language="VB" runat="server">
...
Sub Page_Load()
        selGroups.DataSource=Session("AllGroups")
        selGroups.DataBind()
        selForums.DataSource=Session("AllGroups")
        selForums.DataBind()
End Sub

wrECKster · August 20th, 2003, 03:07 AM

The ascx (control) code would be :

Code:

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
        If Not Page.IsPostBack Then
            BindData()

        End If

    End Sub

    Sub BindData()

        If Session("MyList") Is Nothing Then
            DropDownList1.Visible = False
        Else
            Dim arrList As ArrayList
            arrList = Session("MyList")

            DropDownList1.DataSource = arrList
            DropDownList1.DataBind()
        End If

    End Sub

Then create the session as follows:

Code:

        Dim arrList As New ArrayList
        arrList.Add("Oranges")
        arrList.Add("Apples")
        arrList.Add("Bananas")

        Session("MyList") = arrList

fyeojo · September 2nd, 2003, 03:13 AM

thx