Export GridView to CSV in excel / VB.NET file

Navigation
0

Following examples found on the web and even in stackoverflow I filled in the btnGerarCSV button that way. 

Protected Sub btnGerarCSV_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnGerarCSV.Click
     Dim sb As New StringBuilder
     Dim gv As New GridView
            Try
                Page.Response.Clear()
                Page.Response.Buffer = True
                Page.Response.AddHeader("content-disposition", "attachment;Pedido_" & Session("ddlPedido") & ".csv")
                Page.Response.Charset = ""
                Page.Response.ContentType = "application/vnd.ms-excel"                

                grdPedido.DataSource = Session("dtPedidosColetados")

                For i As Integer = 0 To grdPedido.Columns.Count - 1
                    'Adiciona separador por vírgula
                    sb.Append(grdPedido.Columns(i).HeaderText + ","c)
                Next
                'Adiciona nova linha
                sb.Append(vbCr & vbLf)

                For i As Integer = 0 To grdPedido.Rows.Count - 1
                    For j As Integer = 0 To grdPedido.Columns.Count - 1
                        'Adiciona separador por  vírgula
                        sb.Append(grdPedido.Rows(i).Cells(j).Text + ","c)
                    Next
                    'Adiciona nova linha
                    sb.Append(vbCr & vbLf)
                Next

                Response.Output.Write(sb.ToString())
                Response.Flush()
                Response.End()

            Catch ef As ThreadAbortException
                Exit Try
            Catch ex As Exception

            End Try

        End Sub

My page works as follows: The user chooses Start Date and End Date and selects the search button. Then grdPedido is populated and displayed on screen. After that two buttons are displayed, one to export to excel in worksheet, which is working correctly and a button for CSV.

But what happens to me is that on arriving at the line For i As Integer = 0 To grdPedido.Columns.Count - 1 the number of columns is = 0, even the grid returning the query normally.

I've changed the code in several ways, but it always falls into the same problem.

    
asked by anonymous 22.09.2015 / 15:22

1 answer

0

After much fighting with this code, I found a way to solve the problem of columns always returning 0

I inserted a Directcast to convert the gv.DataSource to an object and then use another Directcast to transform the object into a DataTable 

For i As Integer = 0 To DirectCast(DirectCast(gv.DataSource, System.Object), System.Data.DataTable).Columns.Count - 1
                'Adiciona separador por vírgula
                'sw.Write(gv.Columns(i).HeaderText + ","c) Como estava antes
                sw.Write(DirectCast(DirectCast(gv.DataSource, System.Object), System.Data.DataTable).Columns(i).ColumnName + ","c)
            Next
            'Adiciona nova linha
            sw.Write(vbCr & vbLf)

            For i As Integer = 0 To gv.Rows.Count - 1
                'For j As Integer = 0 To gv.Columns.Count - 1 Como estava antes
                For j As Integer = 0 To DirectCast(DirectCast(gv.DataSource, System.Object), System.Data.DataTable).Columns.Count - 1
                    'Adiciona separador por  vírgula
                    sw.Write(gv.Rows(i).Cells(j).Text + ","c)
                Next
                'Adiciona nova linha
                sw.Write(vbCr & vbLf)
            Next

I do not know if it is the simplest form, but only then can I get the return of the columns.

    
06.10.2015 / 14:58
Indicate form which method of the class to use Image is being uploaded without extension