Control 'DataLoading1_gdvDataGroups_ctl01_ctl00' of type 'DataControlLinkButton' must be placed inside a form tag with runat=server

Question

I'm trying to export the contents of an ASP.NET gridView control to an Excel spreadsheet. To do this I've been using the code on this page .

When it gets to the RederControl(hw) line though my code blows up. I get an error like:

GridView must be placed inside a form tag with runat=“server” even after the GridView is within a form tag

To solve this I found this answer . However the main answer does not work and I think it is because my code is in an .ascx user control. With that in mind I tried the solutions in the second highest rated answer.

This time I get error relating to the DataControlLinkButtons similar to the title of this question.

My gridview contains hyperlinks inside in the cells of one column. I tried to remove them from their parent control prior to rendering with the following code (as per the second answer on that page)

List<int> gridIndexes=new List<int>();
for (int i = 1; i < gdvDataGroups.Controls[0].Controls.Count-1; i++)
{   
    gridIndexes.Add(gdvDataGroups.Controls.IndexOf(gdvDataGroups.Controls[0].Controls[i].Controls[8].Controls[1]));
    gdvDataGroups.Controls.Remove(gdvDataGroups.Controls[0].Controls[i].Controls[8].Controls[1]);
}

but it didn't work for me and I got the same error.

Any ideas of how to approach this?

The gridView is as follows (with only the relevant 9th column included):

 <asp:GridView ID="gdvDataFiles" SkinID="MediumSpace" runat="server" AutoGenerateColumns="False"
                        ShowHeader="true" Width="100%" OnPageIndexChanging="gdvDataFiles_PageIndexChanging"
                        AllowPaging="True" PageSize="20">
                        <Columns>                              
                            <asp:TemplateField HeaderText="Details" ItemStyle-Width="80px" ItemStyle-HorizontalAlign="Center">
                                <ItemTemplate>
                                    <asp:HyperLink ID="HyperLink1" runat="server" Text='<%# Eval("RequestPKID") == null ? "Not available" : "View" %>'
                                        NavigateUrl='<%# Eval("RequestPKID") == null ? "" : Eval("RequestPkid", "../Pages/BOLoadDetails.aspx?fileid={0}") %>'
                                        Style="padding-top: 4px; display: block" />
                                </ItemTemplate>
                            </asp:TemplateField>                                
                        </Columns>
                        <EmptyDataTemplate>
                            No data file loads found
                        </EmptyDataTemplate>
                    </asp:GridView>

Answer 1

Ok turns out that I needed to disable the sorting on the grid prior to rendering the spreadsheet. I think it was the sort control buttons that were causing the problem.