Export dynamic asp table to Excel

Question

I created a dynamic asp table in code behind and had an export function to export the table to Excel, but the output Excel is blank without any data.

The export function works properly if it is a static html table.

Is there any method to export a dynamic asp table?

<asp:Table id="tbl_data" runat="server" Width="95%" BackColor="White" BorderColor="Black" 
BorderWidth="1" ForeColor="Black" GridLines="Both" BorderStyle="Solid">
</asp:Table>

Code behind:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    If Not Page.IsPostBack Then           
       Dim trr1 As New TableRow
        Dim tdr1_1 As New TableCell
        Dim tdr1_2 As New TableCell
        Dim tdr1_3 As New TableCell
        Dim i As Integer = 0

        'Table Header

        '2nd row
        Dim tr As New TableRow
        Dim td1 As New TableCell
        td1.Text = "Staff</br>No."

        Dim td2 As New TableCell
        td2.Text = "Display name (Know As)"

        Dim td3 As New TableCell
        td3.Text = "Current</br>Project/Office"

        Dim td4 As New TableCell
        td4.Text = "Current</br>Department"

        Dim td5 As New TableCell
        td5.Text = "Current</br>Title"

        tr.Cells.Add(td1)
        tr.Cells.Add(td2)
        tr.Cells.Add(td3)
        tr.Cells.Add(td4)
        tr.Cells.Add(td5)

        'another table cells
        'xxxxxxxxxxxxxxxxxxxxxxx

        tbl_data.Rows.AddAt(tbl_data.Rows.Count, tr)

    end if
end sub

Protected Sub RadToolBar1_ButtonClick(ByVal sender As Object, ByVal e As Telerik.Web.UI.RadToolBarEventArgs) Handles RadToolBar1.ButtonClick
    If e.Item.Value = "Export" Then
        Dim sw As New StringWriter()
        Dim hw As New System.Web.UI.HtmlTextWriter(sw)
        Dim frm As HtmlForm = New HtmlForm()

        Page.Response.AddHeader("content-disposition", "attachment;filename=PDR_Submission_Status_Report.xls")
        Page.Response.ContentType = "application/vnd.ms-excel"
        Page.Response.Charset = ""
        Page.EnableViewState = False
        frm.Attributes("runat") = "server"
        Controls.Add(frm)
        frm.Controls.Add(tbl_data)
        frm.RenderControl(hw)
        Response.Write(sw.ToString())
        Response.End()

    End If
End Sub 

Answer 1

Your table is not generated after your button click (If Not Page.IsPostBack Then ), so therefore you have no data to export.

Do the table-generation outside the If Postback block, and all will be fine :)

Answer 2

Below Code will help you.If you set dynamic generate table in any server variable and use it then it will work.

 Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
    If Not Page.IsPostBack Then
        Dim trr1 As New TableRow
        Dim tdr1_1 As New TableCell
        Dim tdr1_2 As New TableCell
        Dim tdr1_3 As New TableCell
        Dim i As Integer = 0
        Dim tr As New TableRow
        Dim td1 As New TableCell
        td1.Text = "Staff</br>No."
        Dim td2 As New TableCell
        td2.Text = "Display name (Know As)"
        Dim td3 As New TableCell
        td3.Text = "Current</br>Project/Office"
        Dim td4 As New TableCell
        td4.Text = "Current</br>Department"
        Dim td5 As New TableCell
        td5.Text = "Current</br>Title"
        tr.Cells.Add(td1)
        tr.Cells.Add(td2)
        tr.Cells.Add(td3)
        tr.Cells.Add(td4)
        tr.Cells.Add(td5)
        tbl_data.Rows.AddAt(tbl_data.Rows.Count, tr)
        Session("TempData") = tbl_data
    End If
  End Sub
  Protected Sub btn_Click(sender As Object, e As System.EventArgs) Handles btn.Click
    Dim sw As New StringWriter()
    Dim hw As New System.Web.UI.HtmlTextWriter(sw)
    Dim frm As HtmlForm = New HtmlForm()

    Page.Response.AddHeader("content-disposition", "attachment;filename=PDR_Submission_Status_Report.xls")
    Page.Response.ContentType = "application/vnd.ms-excel"
    Page.Response.Charset = ""
    Page.EnableViewState = False
    frm.Attributes("runat") = "server"
    Controls.Add(frm)
    frm.Controls.Add(Session("TempData"))
    frm.RenderControl(hw)
    Response.Write(sw.ToString())
    Response.End()
  End Sub