Simple export from ASP.NET GridView into Excel VB.NET - asp.net

Question

I have a GridView that I need to export into Excel (by button event) and I'm using Visual Studio and vb.net.
I never tried this before and I'm kinda clueless, is there a simple way to do this? I don't think I need any complications at the moment, just a simple export of the GridView information.
Also I already got a connection between the GridView and my database. I tried adding a working Excel export from other project but I still miss something .
Public Overrides Sub VerifyRenderingInServerForm(ByVal control As Control)
' Verifies that the control is rendered
End Sub
Protected Sub exportExelBtn_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles exportExelBtn.Click
Dim errorCheck As Integer = 0
Dim popupscript As String = ""
If approvalGrid.Rows.Count > 0 Then
Try
Response.ClearContent()
Response.Buffer = True
Response.AddHeader("content-disposition", String.Format("attachment; filename={0}", "TestPage.xls"))
Response.ContentEncoding = Encoding.UTF8
Response.ContentType = "application/ms-excel"
' Dim sw As New stringwriter()
Dim tw As New IO.StringWriter()
Dim htw As New HtmlTextWriter(tw)
approvalGrid.RenderControl(htw)
Response.Write(tw.ToString())
Response.[End]()
Catch ex As Exception
errorCheck = 1
End Try
Else
errorCheck = 1
End If
If errorCheck = 1 Then
'a pop up error messege feature
popupscript = "<script language='javascript'>" + "alert(" + Chr(34) + "There was an error in exporting to exel, please make sure there is a grid to export!" + Chr(34) + ");</script>"
End If
Page.ClientScript.RegisterStartupScript(Me.GetType(), "PopUpWindow", popupscript, False)
End Sub
The problem is that the file that it creates upon click says it's not Excel format and when I agree to open it I do see the GridView information as I wanted but I also see a lot of extra info in the form of buttons calanders and other stuff from my page, how can I prevent the export of those other stuff?

Answer 1

Please Try Below code
Public Overrides Sub VerifyRenderingInServerForm(control As Control)
' Verifies that the control is rendered
End Sub
Protected Sub btnExport_Click(sender As Object, e As EventArgs)
If gridview.Rows.Count > 0 Then
Try
gridview.Columns(0).Visible = False
Response.ClearContent()
Response.Buffer = True
Response.AddHeader("content-disposition", String.Format("attachment; filename={0}", "TestPage.xls"))
Response.ContentEncoding = Encoding.UTF8
Response.ContentType = "application/ms-excel"
Dim sw As New StringWriter()
Dim htw As New HtmlTextWriter(sw)
gridview.RenderControl(htw)
Response.Write(sw.ToString())
Response.[End]()
Catch ex As Exception
Finally
gridview.Columns(0).Visible = True
End Try
End If
End Sub

Answer 2

I have written above code to export gridview to excel file, it exports successfully but there are some content in gridview in Persian language which is shown unreadable in exported excel file. the code I have written is as below:
Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
If GridView1.Rows.Count > 0 Then
Response.ClearContent()
Response.Buffer = True
Response.AddHeader("content-disposition", String.Format("attachment; filename={0}", "IncentiveReport.xls"))
Response.ContentEncoding = Encoding.UTF8
Response.ContentType = "application/ms-excel"
Dim sw As New IO.StringWriter()
Dim htw As New HtmlTextWriter(sw)
GridView1.RenderControl(htw)
Response.Write(sw.ToString())
Response.End()
End If
End Sub
Public Overrides Sub VerifyRenderingInServerForm(control As Control)
' Verifies that the control is rendered
End Sub