How do I access RadNumericTextBox in footer template, from Server side?

[Steve]

I have no clue why, but this code was working yesterday and today it doesn't.

I have the following grid:

<telerik:RadGrid ID="RadGrid1" runat="server" AllowPaging="True" DataSourceID="Products"
    Skin="Forest" GridLines="None" OnItemDataBound="RadGrid1_ItemDataBound" Width="50%">
    <ClientSettings>
         <Scrolling AllowScroll="True" UseStaticHeaders="True" SaveScrollPosition="true" ></Scrolling>
            <ClientEvents OnBatchEditCellValueChanged="CellValueChanged" />
    </ClientSettings>
    <MasterTableView ShowFooter="true" AutoGenerateColumns="False"
        CurrentResetPageIndexAction="SetPageIndexToFirst" DataKeyNames="ID" DataSourceID="Products"
        Dir="LTR" Frame="Border" TableLayout="Auto" EditMode="Batch" BatchEditingSettings-OpenEditingEvent="Click" CommandItemDisplay="None">
        <Columns>
            <telerik:GridBoundColumn DataField="ID" DataType="System.Int32"  ReadOnly="True" UniqueName="ID" />
            <telerik:GridBoundColumn DataField="ProductName" ReadOnly="true" HeaderText="Product" UniqueName="ProductName" />

            <telerik:GridTemplateColumn DataField="Quantity" UniqueName="Quantity" HeaderText="Quantity" DataType="System.Int32">
                <ItemTemplate>
                    <%# Eval("Quantity")%>
                </ItemTemplate>
                <EditItemTemplate>
                    <telerik:RadNumericTextBox ID="txtQuantity" runat="server" Width="40px" DataType="System.Int32"
                         NumberFormat-DecimalDigits="0" Skin="Forest">
                        <ClientEvents OnBlur="Blur" OnFocus="Focus" />
                    </telerik:RadNumericTextBox>
                </EditItemTemplate>
                <FooterTemplate>
                    <telerik:RadNumericTextBox ID="TextBox2" runat="server" Width="40px" DataType="System.Int32" NumberFormat-DecimalDigits="0" Skin="Forest" ReadOnly="True">
                        <ClientEvents OnLoad="Load" />
                    </telerik:RadNumericTextBox>
                </FooterTemplate>
            </telerik:GridTemplateColumn>
        </Columns>
    </MasterTableView>
    <PagerStyle Mode="NextPrevAndNumeric" />
</telerik:RadGrid>

With the following javascript:

<telerik:RadScriptBlock runat="server" ID="RadScriptBlock1">
    <script type="text/javascript">
        var sumInput = null;
        var tempValue = 0;
        function Load(sender, args) {
            sumInput = sender;
        }
        function Blur(sender, args) {
            sumInput.set_value(tempValue + sender.get_value());

        }
        function Focus(sender, args) {
            tempValue = sumInput.get_value() - sender.get_value();
        }
        function CellValueChanged(sender, args) {
            var row = args.get_row();
            var rowIndex = row.rowIndex;
            var columnName = args.get_columnUniqueName();
            var cell = args.get_cell();
            var oldValue = args.get_cellValue();
            var newValue = '' + args.get_editorValue();
            var key = '' + row.cells[0].textContent

            //debugger
            var hc = document.getElementById('<%= ProductHash.ClientID%>');
            if (hc.value == '') {
                if (newValue == "0") {
                    return;
                }
                aProducts = new Array();
                aProducts[key] = newValue;
            }
            else {
                var aProducts = JSON.parse(hc.value);
                if (aProducts == null) {
                    if (newValue == "0") {
                        return;
                    }
                    aProducts = new Array();
                    aProducts[key] = newValue;
                }
                else {
                    aProducts[key] = newValue;

                }
            }
            hc.value = JSON.stringify(aProducts);
        }
    </script>
</telerik:RadScriptBlock>

And the following server side code:

    Protected Sub btnProcess_Click(sender As Object, e As EventArgs)
        Try
            'Retrieve total quantity from footer
            Dim footer As GridFooterItem = DirectCast(RadGrid1.MasterTableView.GetItems(GridItemType.Footer)(0), GridFooterItem)
            Dim TotalQty As String = TryCast(footer.FindControl("TextBox2"), RadNumericTextBox).Text

.......do some stuff

        Catch ex As Exception
            Response.Write(ex.ToString)
        End Try
    End Sub

Yesterday, I was able to populate TotalQty with the value from the footer, but today, it is an empty string. The footer textbox shows a number in it. Server side, I am getting access to the footer textbox, but the Text property is an empty string.

I have no clue why it stopped working.

[Steve]

Well, I found the problem.
I had an open ticket with Telerik regarding trying to put the grid in and out of edit mode from the code behind without causing a javascript error. They recommended I do a RadGrid1.Rebind() after setting the EditMode.

If bEditMode Then
    RadGrid1.MasterTableView.EditMode = Telerik.Web.UI.GridEditMode.Batch
    RadGrid1.Rebind()
Else
    RadGrid1.MasterTableView.EditMode = Nothing
    RadGrid1.Rebind()
End If

Well, that apparently makes it so the textbox in the footer can't pass it's value back to the code behind.
As soon as I comment out the Rebind, I gain access to the textbox in the footer.

So, I'm back to square one again regarding putting the grid in and out of edit mode safely...