RegisterForEventValidation can only be called during Render();

 

 

When we export gridview data to excel,word,notepad and csv using asp.net  we found this type of error :

 

 

This error occurs whenever we are trying to render control to response. To solve this problem I have added EnableEventValidation="false" to @Page directive of aspx page that should be just like this 

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ExportGridviewtoExcel.aspx.cs" Inherits="ExportGridviewtoExcel" EnableEventValidation="false"%>

By Setting EnableEventValidation="false" property to @Page directive of aspx page the problem has solved automatically.

 

 

Second problem in export to excel is  :

 

  "Control 'GridView1' of type 'GridView' must be placed inside a form tag with runat=server."

 

 

Add this code in server side :

 

 

public override void VerifyRenderingInServerForm(Control control)
    {
        //It solves the error "Control 'GridView1' of type 'GridView' must be placed inside a form tag with runat=server."
    }