Asp.net gridview到excel

在asp.net vs05上工作。当我将gridview导出到excel时，会出现以下错误

只能在Render（）期间调用RegisterForEventValidation

为什么我会出现这个错误。如何解决

public void ToExcel()
{
    string attachment = "attachment; filename=Employee.xls";
            Response.ClearContent();
            Response.AddHeader("content-disposition", attachment);
            Response.ContentType = "application/ms-excel";
            StringWriter stw = new StringWriter();
            HtmlTextWriter htextw = new HtmlTextWriter(stw);
            gvSearch.RenderControl(htextw);
            Response.Write(stw.ToString());
            Response.End(); 
}


 public override void VerifyRenderingInServerForm(Control control)
    {

    }

//--添加到excel中处理特殊字符

Response.ContentEncoding = Encoding.Unicode;
                     Response.BinaryWrite(Encoding.Unicode.GetPreamble());

                     gvSearch.EnableViewState = false;

//--添加到excel中处理特殊字符

Response.ContentEncoding = Encoding.Unicode;
                     Response.BinaryWrite(Encoding.Unicode.GetPreamble());

                     gvSearch.EnableViewState = false;

添加这些行，看看是否有帮助

StringWriter stw = new StringWriter(); 
            HtmlTextWriter htextw = new HtmlTextWriter(stw); 
            gvSearch.RenderControl(htextw); 
            Response.Write(stw.ToString()); 
            Response.End();  
} 

---

这是在黑暗中拍摄的

在aspx页面中，将以下内容更改为false:allowpage=“false”AllowSorting=“false”并删除Pagesize=“10”。

我仍然收到此错误“RegisterForEventValidation只能在呈现（）期间调用；”