.NET Tutorials, Forums, Interview Questions And Answers
Welcome :Guest
Sign In
Win Surprise Gifts!!!

Top 5 Contributors of the Month
Gaurav Pal
Post New Web Links

Error when trying to export gridview to Excel - RegisterForEventValidation can only be called during

Posted By:      Posted Date: October 14, 2010    Points: 0   Category :ASP.Net
I have a pretty basic vb.net page that has textbox control on it and a "generate" button that when clicked, fills a datagrid.  That all works great, but when the user clicks the "Export to Excel" button, I get this error.. RegisterForEventValidation can only be called during Render(); 

Here's my code behind, I thought I included everything I needed...

Public Overrides Sub VerifyRenderingInServerForm(ByVal control As Control)
End Sub

Private Sub ExportToExcel(ByVal strFileName As String, ByVal dg As GridView)
        Response.Buffer = True
        Response.ContentType = "application/vnd.ms-excel"
        Response.AddHeader("content-disposition", "attachment;filename=" & strFileName)
        Response.Charset = ""
        Me.EnableViewState = False
        Dim StringWriter As New System.IO.StringWriter()
        Dim HtmlTextWriter As New System.Web.UI.HtmlTextWriter(Str

View Complete Post

More Related Resource Links

Export Gridview data to Excel sheet


Hi ,

     I have a requirement where i need to export the gridview data to excel.My code export the data in excel that was fine.

But the enchancement needed now , I was exporting the 3 gridview in same excel sheet under the workbook.

Now i need to export the 3 grid view in 3 different sheet in the same workbook.

so can please tell or share the updated code in my below code ...

public void writeovrsummary()


        Response.Write("Overall Summary");
        //Response.Write("Report as of " + DateTime.Now.ToString("hh:mm ss tt"));

        StringWriter sw = new StringWriter();
        HtmlTextWriter hw = new HtmlTextWriter(sw);

        SqlCommand com = MyConnection.CreateCommand();
        com.CommandText = "useroverall_Report";
        SqlParameter[] par = new SqlParameter[1];
        par[0] = new

Export altered gridview to Excel


Hello... stuck on this one!!  In a gridview RowDataBound named gvwResult I am altering one of the cells with a value retrieved from the query.

I have added:

if (hdnExchangeTo.Value.ToString() != "1")
            for (int i =0; i < gvwResult.Rows.Count; i++)
                gvwResult.Rows[i].Cells[7].Text = ExchangeCurrency(gvwResult.Rows[i].Cells[7].Text.ToString());

to the common code to export to Excel:

        Response.Buffer = true;
        Response.Charset = "";
        Response.ContentType = "application/vnd.ms-excel";
        System.IO.StringWriter sw = new Syste

String Data missing start from "+" When Export Data To Excel Using Gridview

Hi,I am exporting data from gridview to excel file.My problem is that for all the string which contain "+", the rest of data begining from it is missing in excel file.For example: PWE-WER+78, when exported it will become PWE-WER.Below is my code.                Response.ClearContent() Response.Buffer = True Response.AddHeader("Content-Disposition", "attachment;filename=" & "ExportedExcel.xls") Response.ContentType = "application/vnd.ms-excel" Response.Charset = "" lobjStringWriter = New StringWriter lobjHtmlWriter = New HtmlTextWriter(lobjStringWriter) dgdResult.RenderControl(lobjHtmlWriter) Response.Write(lobjStringWriter.ToString()) Response.End() I  have search through online but no solution.Does anyone has idea on this?

How to export gridview to excel template

I have a gridview that I need to export to Excel. Excel is not installed on the server, but I would like to put a template on the server so that when the user exports the data it will use the template and open the file on the user's local machine. To make things slightly more complex, I need to export the data to Sheet2 because Sheet1 needs to be a graph (thus the need for the template). I cannot use any third party software and I have no ability to modify anything on the server. This is used in a corporate environment on a shared server that I don't have any control over. Any sample code would be very helpful. I'm running ASP.NET 3.5 with Visual Studio 2008.

ASP.NET-Gridview - Export to excel- column format

Hi All, I am exporting gridview data into excel sheet. I have a column  which is a code for which data is like 012,013 etc. But when this data is being exported , in the excel sheet I can see the data as 12,13,14. but actually it should be 012.... Is there any way to specify the format of such columns in my datatable so that they are in the same manner as in the database? Please provide some information on this.Thanks in advance.

Error Server Unavailable when try to export it to Excel



I am using SSRS 2005 Version 9.00.4035.00

When i run a query and the query results in 105122 row and when i try to export to it excel I get an

Server Application Unavailable

The web application you are attempting to access on this web server is currently unavailable.  Please hit the "Refresh" button in your web browser to retry your request.

Administrator Note: An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur.

In my group i have added =Ceiling(RowNumber(Nothing)/65000) so that it goes to the next page but it doesnt work


any help will be appreciated




gridview export to excel


The export to excel work successfully, but a name like this D'Costa is converted to Dâ?TCosta.

Any name with the tick converts within excel. Is there a fix?



Export a Query to Gridview then Excel


I have not done this before so pardin this question that I am sure has been asked before.

I have a user that asks me to run queries each month and copy & paste the data into a spreadsheet

I want to set up the queries in a web page for him to choose, enter the data in the parameters

and either show the data in a gridview then export or just export to the spreadsheet

direclty to the file name and location of his choice.

Using C#

Links or code samples would great.

Export GridView to Excel using .net 2010 (C#)


Can anyone tell me how to export gridview to excel using asp.net 2010? C# is the script language

what i have is working in VS2008 but not working in VS2010:

 public override void VerifyRenderingInServerForm(Control control)

after clicking the button:





Response.Charset = "" ;

Response.ContentEncoding = System.Text.Encoding .UTF8;

Response.Charset = "" ;

export the gridview data to excel problem



i am using master page and child pages in the child page

i want to export the gridview data to excel sheet for this i use the following code


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

        Response.ContentType = "application/excel";

        StringWriter sw = new StringWriter();

        HtmlTextWriter htw = new HtmlTextWriter(sw);




but in the gridShedules.RenderControl(htw) i got the following error but the form tag with  runat= server is already in the master page how to solve this issue

error:Control 'ctl00_ContentPlaceHolder1_grdshedules' of type 'GridView' must be placed inside a form tag with runat=server.

Getting error in report when export to excel


Hi all,
I am using local reports(rdlc) files for reports generation in Asp.net
I am getting following error.
Excel Rendering Extension : "Number of rows in the excel sheet exceeded the limit of 65536 rows"
How can i solve this error.


Export to Excel big size files (10000 pages) - HTTP Error 401.1



If you attempt to export a file to Excel, the browser hangs for a long time, then begins to request authorization, several times in succession .
Then displays an error message: "you are not authorized to view this page"

Export to Excel gives error before opening file


I have a web page with a gridview control and a button for Exporting to Excel

I get following error when exporting to Excel.

"The fiel you are trying to open, 'someFileName[1].xls, is in a different format than specified by the file extension. Verify that file is not corrupted and is from a trusted source before opening the file. Do you want to open the file now?"

Clicking Yes opens the file. I would like to avoid showing the above error to the users.

Following code is used from the click event. I've left the commented code here to show what I've tried based on results from internet search. I have Microsoft Office Excel 2007 on local PC.

public static void ToExcel(DataTable dt, string fileName)
			string attachment = "attachment; filename=" + fileName + ".xls";

			GridView gvExcel = new System.Web.UI.WebControls.GridView();
			gvExcel.AutoGenerateColumns = true;
			gvExcel.DataSource = dt;

			//HttpContext.Current.Response.AddHeader("content-disposition", attachment);
			//HttpContext.Current.Response.ContentType = "application/ms-excel";
			HttpContext.Current.Response.ContentType = "application/vnd.ms-excel";

SQL Express R2 - Import / Export Data (32-bit) - Excel - Unexpected Unrecoverable Error


Preface - I'm BRAND NEW to SQL! Bought a book and working to learn :) I've have a lot of experience in Access and other msft titles.

I've installed SQL Express 64 bit on Win 7 (64) and I'm trying to setup my 1st table to start practicing running queries on and I’m having nothing but trouble!! I'm trying to use the import / export wizard to import Excel '07 spreadsheet that has a table of data and I CANNOT get through this without crashing! EVERY SINGLE TIME!

My Steps:

1.  Open Wizard

How to export data to excel from gridview and DataTable using asp.net?

In this article we will see how to export data from gridview control and dataTable to excel file in a simple way.

Export Visio Database Table Names to Excel

If you use the Enterprise Architect edition of Microsoft Visio for data modeling regularly, then there is a good chance that at some point you've wanted to export just the table names into Excel. You might want to do this to map logical ERD entities to physical data model tables, track project status by entity, or track overlap between database versions.

display data into GridView from excel sheet

I have to display data from excel sheet into my gridview and also I need to figure out a way to store data into excel files from my web page. I am using C# 3.5, VS 2008.
ASP.NetWindows Application  .NET Framework  C#  VB.Net  ADO.Net  
Sql Server  SharePoint  Silverlight  Others  All   

Hall of Fame    Twitter   Terms of Service    Privacy Policy    Contact Us    Archives   Tell A Friend