I have an ordering page where the quantity of each product is limited to 
the maximum number allowed. The quantity is entered through a dynamic drop 
down list, with the data source is defined by calling a function returning 
the data view. The product list is bound to a repeater.

I tried using findcontrol to retrieve the selected value, but it returns 
0. How can I return the selected drop down list value?

Please see below is the aspx code.

<%@ Page Language="VB" Debug="true" %>
<%@ import Namespace="System.Data" %>
<%@ import Namespace="System.Data.SqlClient" %>
<%@ import Namespace="System.Data.Common" %>
<script runat="server">

dim cnx as SQLConnection
dim objSQLCommand as SqlCommand
dim ObjDataReader As SqlDataReader

cnx = new SqlConnection("Server=LocalHost;uid=sa;pwd=;Database=ite")

sub Page_Load(Src As Object, E As EventArgs)

    dim intProjectID as integer
    intProjectID = 1
  
    objSQLCommand = New SqlCommand("usp_select_Product_by_ProjectID", cnx)
    objSQLCommand.CommandType = CommandType.StoredProcedure
    
    objSQLCommand.Parameters.Add(New SqlParameter("@ProjectID", 
SqlDbType.int))
    objSQLCommand.Parameters("@ProjectID").Value = intProjectID
    
    cnx.Open()
    myRepeater.DataSource = objSQLCommand.ExecuteReader()
    myRepeater.DataBind()
    cnx.Close()
    
end sub
    
    
    
    
sub btnInsert_Click (Sender As Object, E as EventArgs)
    
    objSqlCommand = New SqlCommand("usp_insert_SalesOrderMain",cnx)
    objSqlCommand.CommandType = CommandType.StoredProcedure
    dim objParameter As SqlParameter
    dim objOutputParameter As SqlParameter
    
    'Build parameters for input/output procedure
    '
    '
    ' 
    
    'Last input parameter
     objParameter = New SqlParameter("@CallStartDate",SqlDbType.DateTime)
     objSqlCommand.Parameters.Add(objParameter)
     objParameter.Direction = ParameterDirection.Input
     objParameter.Value = txtCallStartDate.text
    'Output parameter, SalesOrderID
     objOutputParameter = New SqlParameter("@SalesOrderID",SqlDbType.Int)
     objSqlCommand.Parameters.Add(objOutputParameter)
     objOutputParameter.Direction = ParameterDirection.Output
    
     cnx.open()
    
     objDataReader = objSqlCommand.ExecuteReader()
     
     dim intSalesOrderID as Integer
     intSalesOrderID = objOutputParameter.Value
    
     cnx.Close()
    
         
     'Loop through repeater            
     Dim I As Long
     Dim CurrentDropDownList As DropDownList
     Dim CurrentLabel As Label
    
     objSqlCommand = New SqlCommand("usp_insert_SalesOrderItem",cnx)
     objSqlCommand.CommandType = CommandType.StoredProcedure
     
     'Loop
     for I=0 To myRepeater.Items.Count -1
    
         CurrentLabel = myRepeater.Items(I).FindControl("lblProductID")
       
         CurrentDropDownList = myRepeater.Items(I).FindControl("ddl")
    
         objParameter = New SqlParameter("@Quantity",SqlDbType.Int)
         objSqlCommand.Parameters.Add(objParameter)
         objParameter.Direction = ParameterDirection.Input
         'CurrentDropDownList.SelectedItem.Text returns 0          
         objParameter.Value = CurrentDropDownList.SelectedItem.Text
    
         objParameter = New SqlParameter("@SalesOrderID",SqlDbType.Int)
         objSqlCommand.Parameters.Add(objParameter)
         objParameter.Direction = ParameterDirection.Input
         objParameter.Value = intSalesOrderID
    
         objParameter = New SqlParameter("@ProductID",SqlDbType.Int)
         objSqlCommand.Parameters.Add(objParameter)
         objParameter.Direction = ParameterDirection.Input
         objParameter.Value = cint(CurrentLabel.Text)
    
         cnx.open()
         dim ObjDataReader2 As SqlDataReader
         objDataReader2 = objSqlCommand.ExecuteReader()
         cnx.Close()
    next
end sub
    
function CreateDataSource(maxQuantity as integer) As ICollection
    Dim dt As New DataTable()
    Dim dr As DataRow
    
    dt.Columns.Add(New DataColumn("Quantity", GetType(Int32)))
    
    Dim i As Integer
    For i = 0 To maxQuantity
        dr = dt.NewRow()
        dr(0) = i
        dt.Rows.Add(dr)
    Next i
    
    Dim dv As New DataView(dt)
    Return dv
end function

</script>
<html>
<head>
</head>
<body>
    <form id="Form1" method="post" runat="server">
        <asp:Repeater id="myRepeater" runat="server">
            <HeaderTemplate>
                <table border="1" cellspacing="0" cellpadding="5">
            </HeaderTemplate>
            <ItemTemplate>
                <tr>
                    <td>
                        <asp:Label id="lblProductID" runat="server" 
text='<%# Container.DataItem("ProductID") %>'></asp:Label>
                    </td>
                    <td>
                        <%# Container.DataItem("ProductDescription") %
></td>
                    <td>
                        <%# Container.DataItem("Price") %> 
                    </td>
                    <td>
                        <asp:DropDownList id="ddl" datasource='<%# 
CreateDataSource(Container.DataItem("maxQuantity")) %>' 
DataValueField= "Quantity" DataValueText= "Quantity" 
runat="server"></asp:DropDownList>
                    </td>
                </tr>
            </ItemTemplate>
            <FooterTemplate>
                </table>
            </FooterTemplate>
        </asp:Repeater>

        <p>
            <asp:Button id="btnInsert" onclick="btnInsert_Click" 
runat="server" Text="Button"></asp:Button>
    </form>
</body>
</html>