How to export pdfTable that is not equal or divisible with the pdfCell count?

问题

I am currently doing a loop from a DataGridView that will read each selected item and create a cell with the item's barcode in it (cells to be exported depends on the quantity the user had input), but If I tried to export 1 barcode label (1 pdfCell) it wouldn't export and says 'the pdfTable is empty' because I have a pdfTable.Columns(5) which is means that my table has a column count of 5. So as long as I try to export cell quantities that are not divisible by 5 it wouldn't export.

Example 1: Item - Banana (10 Barcodes to print) - Exported

Example 2: Item - Apple (1 Barcode to print) - Not Exported (PDFTable is Empty) because 1(one) does not cover a single row of the pdfTable with a column count which is 5(five).

Here is my code for the 'Print Barcode Labels Button' :

Public Function print_itembarcodes(lbl169 As Label)
    Dim pdfTable As New PdfPTable(5)
    pdfTable.DefaultCell.Padding = 3
    pdfTable.WidthPercentage = 100
    pdfTable.HorizontalAlignment = Element.ALIGN_CENTER
    pdfTable.DefaultCell.Border = Rectangle.NO_BORDER

    For i As Integer = 0 To Admin_Menu.BarcodePrintListGrid.Rows.Count - 1
        Admin_Menu.Label169.Text = Admin_Menu.BarcodePrintListGrid.Rows(i).Cells(1).Value 'Item Barcode'
        Barcode.process_printbarcode(Admin_Menu.Label169)  'Make barcode image function'
        save_printbarcode() 'Save barcode to desktop function'

        For j As Integer = 0 To Admin_Menu.BarcodePrintListGrid.Rows(i).Cells(5).Value 'Quantity of barcodes to be printed per item'
            pdfTable.AddCell(create_barcodecell) 'Add cell with barcode function'
        Next

    Next


    Try

        'Exporting to PDF
        Dim folderPath As String = "C:\Temp\"
        If Not Directory.Exists(folderPath) Then
            Directory.CreateDirectory(folderPath)
        End If
        Using stream As New FileStream(folderPath & "temp2.pdf", FileMode.Create)
            Dim pdfdoc As New Document(PageSize.A4, 15.0F, 15.0F, 10.0F, 20.0F)
            PdfWriter.GetInstance(pdfdoc, stream)
            pdfdoc.Open()
            pdfdoc.Add(pdfTable) 'Table Declaration'
            pdfdoc.Close()
            stream.Close()


            System.Diagnostics.Process.Start("C:\\Temp\\temp2.pdf")

        End Using


    Catch ex As MySqlException
        MsgBox(ex.Message)
    Finally
        MysqlConn.Dispose()
    End Try

    Return True
End Function

Here is my code for creating a cell with barcode :

Public Function create_barcodecell()
    Dim SaveFileDialog1 = "D:\School\Capstone\Sta. Lucia East Bowling and Billiard Hall Management System\Item Barcodes\"
    Dim Barcode2 As Image = Image.GetInstance(SaveFileDialog1 + Admin_Menu.Label169.Text + ".jpg") 'Barcode Image'
    Barcode2.ScaleAbsolute(80.0F, 25.0F)
    img.ScalePercent(15.0F) 'Company Logo Image'
    img.Alignment = iTextSharp.text.Image.ALIGN_RIGHT


    Dim titleFont = FontFactory.GetFont(FontFactory.HELVETICA_BOLD, 8)
    Dim paragraph As New Paragraph()

    paragraph.Add(New Chunk(img, 0, 0))
    paragraph.Add(New Chunk("      Item Tag", titleFont))

    Dim pdfCell As New PdfPCell
    pdfCell.UseVariableBorders = True
    pdfCell.BackgroundColor = BaseColor.GRAY
    pdfCell.BorderColorLeft = BaseColor.GREEN
    pdfCell.BorderColorRight = BaseColor.GREEN
    pdfCell.BorderColorTop = BaseColor.GREEN
    pdfCell.BorderColorBottom = BaseColor.GREEN


    pdfCell.AddElement(paragraph)
    pdfCell.AddElement(Barcode2)
    pdfCell.AddElement(New Paragraph("      " + Admin_Menu.Label169.Text, titleFont))


    Return pdfCell
End Function

回答1:

The main issue is

So as long as I try to export cell quantities that are not divisible by 5 it wouldn't export.

If the remaining cells in that table row are to be empty ones, you can solve this by simply adding additional empty cells until you do have a number of cells divisible by 5.

how can I add empty cells?

I have not done any VB programming since the start of this century, so the syntax might need some correction, but basically you simply do

pdfTable.AddCell(New PdfPCell())

to add a new empty cell to pdfTable.

and how can I do that adding empty cells until it is divisible by 5?

Count the number of cells you have added already and add until the count can be divided by 5 without remainder.

Dim Count as Integer = 0
For j As Integer = 1 To Admin_Menu.BarcodePrintListGrid.Rows(i).Cells(5).Value 'Quantity of barcodes to be printed per item'
    pdfTable.AddCell(create_barcodecell) 'Add cell with barcode function'
    Count = Count + 1
Next
While count Mod 5 <> 0
    pdfTable.AddCell(New PdfPCell())
    Count = Count + 1
End While

(I'm not sure about VB details anymore, in particular whether j still exists outside the former For loop and which value it has. Depending on that you may not need a separate counter...)

来源：https://stackoverflow.com/questions/47550078/how-to-export-pdftable-that-is-not-equal-or-divisible-with-the-pdfcell-count