ASP.Net หนูจะทำ GridView ให้เป็น Excel Xls แต่ไม่ต้อง Export ต้องทำยังไงค่ะ

protected void ExportToExcel(object sender, EventArgs e)
{
    Response.Clear();
    Response.Buffer = true;
    Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.xls");
    Response.Charset = "";
    Response.ContentType = "application/vnd.ms-excel";
    using (StringWriter sw = new StringWriter())
    {
        HtmlTextWriter hw = new HtmlTextWriter(sw);
 
        //To Export all pages
        GridView1.AllowPaging = false;
        this.BindGrid();
 
        GridView1.HeaderRow.BackColor = Color.White;
        foreach (TableCell cell in GridView1.HeaderRow.Cells)
        {
            cell.BackColor = GridView1.HeaderStyle.BackColor;
        }
        foreach (GridViewRow row in GridView1.Rows)
        {
            row.BackColor = Color.White;
            foreach (TableCell cell in row.Cells)
            {
                if (row.RowIndex % 2 == 0)
                {
                    cell.BackColor = GridView1.AlternatingRowStyle.BackColor;
                }
                else
                {
                    cell.BackColor = GridView1.RowStyle.BackColor;
                }
                cell.CssClass = "textmode";
            }
        }
 
        GridView1.RenderControl(hw);
           
        //style to format numbers to string
        string style = @"<style> .textmode { } </style>";
        Response.Write(style);
        Response.Output.Write(sw.ToString());
        Response.Flush();
        Response.End();
    }
}

Protected Sub ExportToExcel(sender As Object, e As EventArgs)
	Response.Clear()
	Response.Buffer = True
	Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.xls")
	Response.Charset = ""
	Response.ContentType = "application/vnd.ms-excel"
	Using sw As New StringWriter()
		Dim hw As New HtmlTextWriter(sw)

		'To Export all pages
		GridView1.AllowPaging = False
		Me.BindGrid()

		GridView1.HeaderRow.BackColor = Color.White
		For Each cell As TableCell In GridView1.HeaderRow.Cells
			cell.BackColor = GridView1.HeaderStyle.BackColor
		Next
		For Each row As GridViewRow In GridView1.Rows
			row.BackColor = Color.White
			For Each cell As TableCell In row.Cells
				If row.RowIndex Mod 2 = 0 Then
					cell.BackColor = GridView1.AlternatingRowStyle.BackColor
				Else
					cell.BackColor = GridView1.RowStyle.BackColor
				End If
				cell.CssClass = "textmode"
			Next
		Next

		GridView1.RenderControl(hw)

		'style to format numbers to string
		Dim style As String = "<style> .textmode { } </style>"
		Response.Write(style)
		Response.Output.Write(sw.ToString())
		Response.Flush()
		Response.[End]()
	End Using
End Sub