只能在执行 Render() 的过程中调用 RegisterForEventValidation(RegisterForEventValidation can only be called during Render(); )

当用GridView导出Execl的时候，会发生只能在执行 Render() 的过程中调用 RegisterForEventValidation的错误提示。
有两种方法可以解决以上问题：
1.修改web.config(不推荐)<pages enableEventValidation ="false" ></pages>
2.直接在导出Execl的页面修改
<%@ Page Language="C#" EnableEventValidation = "false" AutoEventWireup="true"

CodeFile="ExportGridView.aspx.cs" Inherits="ExportGridView" %>

附：Gridview导出Execl可分页全部导出代码(C#)

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.IO;

public partial class EXportTest : System.Web.UI.Page
Imports Microsoft.VisualBasic
Imports System
Imports System.IO

Partial Class ManageContentsClass ManageContents
Inherits System.Web.UI.Page

Protected Sub Page_Load()Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
'If Not Me.IsPostBack Then
' If Request.QueryString("username") <> "xucanzhao" Then
' Response.Redirect("default.aspx?returnUrl=nousername")
' End If
'End If
' ClientScript.RegisterStartupScript(Me.GetType(), "haha", "<script>alert('haha');</script>")
End Sub

Protected Sub btnExportExcel_Click()Sub btnExportExcel_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnExportExcel.Click
Response.Clear()
Response.Buffer = True

Response.Charset = "utf-8"

Response.AddHeader("Content-Disposition", "attachment;filename=FileFlow.xls")
Response.ContentType = "application/ms-excel"
Dim strWriter As New StringWriter()
Dim htw As New HtmlTextWriter(strWriter)
GridView1.AllowPaging = False
GridView1.DataBind()
GridView1.RenderControl(htw)
Response.Write(strWriter.ToString)
Response.End()
GridView1.AllowPaging = True
GridView1.DataBind()
End Sub
Public Overrides Sub verifyRenderingInServerForm()Sub verifyRenderingInServerForm(ByVal control As Control)

End Sub
End Class