ObjectDataSource Selecting method can't 'see' any other control's values

Question

I don't even know how to state this clearly, and there's too much code to paste it all in here.

Let me start off with a general description and maybe it'll ring a bell. I have a DataGrid which uses an ObjectDataSource. The ObjectDataSource uses a SelectMethod that calls another method due to the fact that two datepickers are required to filter the results.

When the SelectMethod fires, though, the datepickers are always null.

A related issue is that a button is required to cause the ObjectDataSource to Select and use the two datepicker values which doesn't work at all. It's as if the ObjectDataSource doesn't consult the GridView for the starting index, etc.

If anyone knows of an example of something like this setup (GridView, Date controls, button, ObjectDataSource) that would be great.

Edit: Here's the code.

<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">

   <asp:Label ID="Label39" CssClass="txtSelect" runat="server" Text="Start Date" />
   <cc1:datepicker ID="startDatePicker" runat="server" Width="70px" PaneWidth="150px" SelectedDate="1/1/2000">
      <panetablestyle bordercolor="#707070" borderwidth="1px" borderstyle="Solid" />
      <paneheaderstyle backcolor="#0099FF" />
      <titlestyle forecolor="White" font-bold="true" />
      <nextprevmonthstyle forecolor="White" font-bold="true" />
      <nextprevyearstyle forecolor="#E0E0E0" font-bold="true" />
      <dayheaderstyle backcolor="#E8E8E8" />
      <todaystyle backcolor="#FFFFCC" forecolor="#000000" font-underline="false" bordercolor="#FFCC99" />
      <alternatemonthstyle backcolor="#F0F0F0" forecolor="#707070" font-underline="false" />
      <monthstyle backcolor="" forecolor="#000000" font-underline="false" />
   </cc1:datepicker>

   <asp:Label ID="Label5" CssClass="txtSelect" runat="server" Text="End Date" />
   <cc1:datepicker ID="endDatePicker" runat="server" Width="70px" PaneWidth="150px" SelectedDate="1/1/2020">
      <panetablestyle bordercolor="#707070" borderwidth="1px" borderstyle="Solid" />
      <paneheaderstyle backcolor="#0099FF" />
      <titlestyle forecolor="White" font-bold="true" />
      <nextprevmonthstyle forecolor="White" font-bold="true" />
      <nextprevyearstyle forecolor="#E0E0E0" font-bold="true" />
      <dayheaderstyle backcolor="#E8E8E8" />
      <todaystyle backcolor="#FFFFCC" forecolor="#000000" font-underline="false" bordercolor="#FFCC99" />
      <alternatemonthstyle backcolor="#F0F0F0" forecolor="#707070" font-underline="false" />
      <monthstyle backcolor="" forecolor="#000000" font-underline="false" />
   </cc1:datepicker>

   <asp:Button ID="RetrieveButton" runat="server" Text="Retrieve" OnClick="RetrieveButton_Click" />

   <asp:GridView ID="creditRateGridView" runat="server"
                 DataSourceID="creditRateObjectDataSource"
                 AllowPaging="true"
                 AllowSorting="true"
                 PageSize="10" 
                 Width="900"
                 AutoGenerateColumns="False" 
                 DataKeyNames="EFFECTIVE_DATE"
                 GridLines="Both"
                 EnableSortingAndPagingCallbacks="true">
      <Columns>
         <asp:BoundField   DataField="EFFECTIVE_DATE" HeaderText="Effective Date" 
                           ItemStyle-HorizontalAlign="Right" ReadOnly="True" 
                           SortExpression="EFFECTIVE_DATE" DataFormatString="{0:d}" />
         <asp:BoundField   DataField="REFERENCE_DATE" HeaderText="Reference Date" 
                           ItemStyle-HorizontalAlign="Right" ReadOnly="True" 
                           SortExpression="REFERENCE_DATE" DataFormatString="{0:d}" />
         <asp:BoundField   DataField="GROSS_CREDIT_USED_RATE" HeaderText="Credit Rate" 
                           ItemStyle-HorizontalAlign="Right" ReadOnly="True" 
                           SortExpression="GROSS_CREDIT_USED_RATE" DataFormatString="{0:p}" />
         <asp:BoundField   DataField="ANNUALIZED_YIELD_ACTUAL_AVERAGE_RATE" HeaderText="Yield" 
                           ItemStyle-HorizontalAlign="Right" ReadOnly="True"
                           SortExpression="ANNUALIZED_YIELD_ACTUAL_AVERAGE_RATE" DataFormatString="{0:p}" />
         <asp:BoundField   DataField="DURATION_USED_YEAR" HeaderText="Duration"
                           ItemStyle-HorizontalAlign="Right" ReadOnly="True"
                           SortExpression="DURATION_USED_YEAR" DataFormatString="{0:n2}" />
         <asp:BoundField   DataField="BOOK_VALUE_USED_AMOUNT" HeaderText="Book Value"
                           ItemStyle-HorizontalAlign="Right" ReadOnly="True"
                           SortExpression="BOOK_VALUE_USED_AMOUNT" DataFormatString="{0:c}" />
         <asp:BoundField   DataField="MARKET_VALUE_USED_AMOUNT" HeaderText="Market Value" 
                           ItemStyle-HorizontalAlign="Right" ReadOnly="True"
                           SortExpression="MARKET_VALUE_USED_AMOUNT" DataFormatString="{0:c}" />
         <asp:BoundField   DataField="MV_BV_RATE" HeaderText="MV/BV Ratio"
                           ItemStyle-HorizontalAlign="Right" ReadOnly="True"
                           SortExpression="MV_BV_RATE" DataFormatString="{0:p}" />
      </Columns>
      <PagerSettings Mode="NumericFirstLast" FirstPageText="First" LastPageText="Last" />
      <PagerStyle HorizontalAlign="Center" />
   </asp:GridView>

   <asp:ObjectDataSource ID="creditRateObjectDataSource" runat="server"
                         EnablePaging="true"
                         TypeName="AegonSVS.Restricted.CreditRateHistory"
                         SelectMethod="CreditRateSelectMethod" 
                         StartRowIndexParameterName="startRowIndex"
                         MaximumRowsParameterName="maximumRows"
                         SortParameterName="sortExpression"
                         SelectCountMethod="CreditRateSelectCountMethod" />

</asp:Content>


public partial class CreditRateHistory : System.Web.UI.Page
   {
      private const int contractId = 1;

      protected void Page_Load(object sender, EventArgs e)
      {
         Session.Add("startDateTime", startDatePicker.SelectedDate);
         Session.Add("endDateTime", endDatePicker.SelectedDate);
      }

      public DataTable CreditRateSelectMethod(int startRowIndex, int maximumRows, string sortExpression)
      {
         var startDateTime = (DateTime)Session["startDateTime"];
         var endDateTime = (DateTime)Session["endDateTime"];

         DataTable dataTable =  Sql.GetCreditRateHistoryPagedRecords(startDateTime,
                                                     endDateTime,
                                                     contractId,
                                                     startRowIndex,
                                                     maximumRows,
                                                     sortExpression,
                                                     null);
         return dataTable;
      }

      public int CreditRateSelectCountMethod()
      {
         var startDateTime = (DateTime)Session["startDateTime"];
         var endDateTime = (DateTime)Session["endDateTime"];

         return Sql.GetCreditRateRowCount(startDateTime,
                                          endDateTime,
                                          contractId,
                                          null);
      }

      protected void RetrieveButton_Click(object sender, EventArgs e)
      {
         // So something with this return? How?
         IEnumerable dataSource = creditRateObjectDataSource.Select();
         creditRateGridView.DataBind();
      }

   }

This is half-way working now. I put the values of the datepickers in the session (which doesn't seem right, but ok for now), and the following method 'works' if the button is clicked twice: protected void RetrieveButton_Click(object sender, EventArgs e) { // So something with this return? How? IEnumerable dataSource = creditRateObjectDataSource.Select(); creditRateGridView.DataBind(); } — Keith Myers, May 03 '11 at 19:49
To fix trouble your need point ObjectDataSource to use current page object instead of creating new. See my answer here: http://stackoverflow.com/a/25846301/451495 — gdbdable, Sep 15 '14 at 10:48

pseudocoder · Accepted Answer · 2011-05-03T20:59:01.930

It sounds like you are expecting code in your ObjectDataSource to have access to your Page object and its children. That is not how it works generally speaking. The code in your ObjectDataSource needs to stand on its own, which means if you need to filter your SQL SELECT using a couple of dates, those dates should be sent as parameters.

If you can post your ObjectDataSource markup and the Class code for your DAL object, I can provide a specific example.

However the general answer to your question can be found in this article:

MSDN: Using Parameters with the ObjectDataSource Control

The problem with using the current Page Class for ObjectDataSource.TypeName is that every time ObjectDataSource binds, it creates a new instance of the Class to work with (with caveats, but that's not important here). This is why you cannot read control values but you can read session. This is why you can't rely on directly accessing items on your page from within your SelectMethod. You need to pass the query parameters in as parameters of the SelectMethod.

It looks like you already have an Class called Sql with (shared?) methods that are set up to do the data access. That is the class your creditRateObjectDataSource.TypeName should reference. Then have creditRateObjectDataSource.SelectMethod be sql.GetCreditRateHistoryPagedRecords, similar to this example:

<asp:ObjectDataSource ID="creditRateObjectDataSource" runat="server" EnablePaging="true"
    TypeName="AegonSVS.Restricted.sql" SelectMethod="GetCreditRateHistoryPagedRecords"
    StartRowIndexParameterName="startRowIndex" MaximumRowsParameterName="maximumRows"
    SortParameterName="sortExpression" SelectCountMethod="CreditRateSelectCountMethod">
    <SelectParameters>
        <asp:ControlParameter Name="startDateTime" ControlID="startDatePicker" PropertyName="SelectedDate"
            DbType="DateTime" />
        <asp:ControlParameter Name="endDateTime" ControlID="endDatePicker" PropertyName="SelectedDate"
            DbType="DateTime" />
        <asp:Parameter Name="contractId" DefaultValue="1" DbType="Int32" />
    </SelectParameters>
</asp:ObjectDataSource>

Yes, you are correct in my assumption. I'll take a look at the article... it certainly sounds like it's in the right direction. — Keith Myers, May 03 '11 at 19:54
Give me a couple hours and I'll get back to you with the code. I see what you're saying: the code behind shouldn't be the class, the Sql class needs to be the type. I wanted to do this but couldn't figure a way to get the dates into the signature. — Keith Myers, May 03 '11 at 20:58
Sorry I didn't read the code well enough the first time. The method you call of the sql class appears to take all the parameters you need, just hook the ObjectDataSource up to it. — pseudocoder, May 03 '11 at 21:00
This seems to be working now. I set up the as you mentioned, cleaned out all the crap I had in the code behind (nothing needed there now except a button handler to call Select() on the ObjectDataSource, and set the Sql class as the TypeName. After that it fires right up, sorting works, my custom paging works... I'm very happy about this :) Thank you very much for your time. — Keith Myers, May 03 '11 at 23:22
No problem, I actually needed a refresher on this material so I'm glad you posted this question. — pseudocoder, May 04 '11 at 14:19
It seems easy when the control where you get your parameter value is simple. In my case it's a multi selection WebControl on wich I need a method to get a list of values. Can I still do it with a SelectParameter? — sinsedrix, Mar 12 '18 at 10:59

ObjectDataSource Selecting method can't 'see' any other control's values

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