GridView to Excel error

[David]

Using ASP.Net 2.0 and I have identical code for exporting a GridView to
Excel in 2 web sites. One works fine and the 2nd one gives me the error
"RegisterForEventValidation can only be called during Render();"

This error occurs on the line that reads "gv.RenderControl(hw)"

Below is my code. Can anybody give me a clue? Thanks.

Sub SendToExcel(ByVal Source As Object, ByVal E As EventArgs)

Dim gv As GridView = SearchResultsGridView

If gv.Rows.Count.ToString + 1 < 65536 Then


gv.AllowPaging = False

gv.AllowSorting = False

If txtSearchText.Text <> "" Then

SqlvwFileSearch.SelectCommand = txtSearchText.Text

End If

gv.DataBind()


Dim tw As New StringWriter()

Dim hw As New System.Web.UI.HtmlTextWriter(tw)

Response.Clear()

Response.ContentType = "application/vnd.ms-excel"

Response.AddHeader("content-disposition", "attachment;filename=search.xls")

Response.Charset = ""

EnableViewState = False

gv.RenderControl(hw)

Response.Write(tw.ToString())

Response.End()

'gv.AllowPaging = True

gv.AllowSorting = True

gv.DataBind()

lblErrorMsg.Text = ""

Else

lblErrorMsg.Text = "Too many rows - Export to Excel not possible"

End If

End Sub


Public Overrides Sub VerifyRenderingInServerForm(ByVal control As
System.Web.UI.Control)

End Sub

David