Loop for PDF Cells always Off by One - vb.net

Question

I am trying to make a barcode label printer through cells. I have a pdfTable that has 3 columns. But everytime I tried to export the pdfTable with a cell count that is not equal or divisible by 3 (which is the number of columns), the cell count are always increasing or off by 1.
For example :
Tried to export 30 cells which is divisible to the pdfTable columns which is 3 (works fine)
Tried to export 1 or 10 cells which is not divisible to the pdfTable columns which is 3 (cell count are always off by 1). Results are like 1 cell become 2 cells and 10 cells become 11 cells.
I always check if there is something wrong with my loop that causes the cells to increase by 1 but I can't find anything.
Here is my code for exporting a PDF :
Public Function print_itembarcodes(lbl169 As Label)
Dim pdfTable As New PdfPTable(3) 'pdfTable Column Count'
pdfTable.DefaultCell.Padding = 3
pdfTable.WidthPercentage = 100
pdfTable.HorizontalAlignment = Element.ALIGN_CENTER
pdfTable.DefaultCell.Border = Rectangle.NO_BORDER
Dim emptyCell As New PdfPCell
emptyCell.Border = 0
Dim count As Integer
count = 0
For i As Integer = 0 To Admin_Menu.BarcodePrintListGrid.Rows.Count - 1 'Read item one by one'
Admin_Menu.Label169.Text = Admin_Menu.BarcodePrintListGrid.Rows(i).Cells(1).Value
Admin_Menu.Label170.Text = Admin_Menu.BarcodePrintListGrid.Rows(i).Cells(0).Value
Admin_Menu.Label171.Text = Admin_Menu.BarcodePrintListGrid.Rows(i).Cells(4).Value
Barcode.process_printbarcode(Admin_Menu.Label169)
save_printbarcode()
For j As Integer = 0 To Admin_Menu.BarcodePrintListGrid.Rows(i).Cells(5).Value 'Cell quantity to be exported for one item'
pdfTable.AddCell(create_barcodecell) 'Create a cell with barcode'
count = count + 1
Next
Next
For k As Integer = 0 To count Mod 3
pdfTable.AddCell(emptyCell)
Next
count = 0
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)
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 the function of 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 + ".png")
Barcode2.ScaleAbsolute(170.0F, 50.0F)
img.ScalePercent(20.0F)
img.Alignment = iTextSharp.text.Image.ALIGN_CENTER
Dim itemname, itemprice, itemcode As New Paragraph
itemname.Alignment = Element.ALIGN_CENTER
itemprice.Alignment = Element.ALIGN_CENTER
itemcode.Alignment = Element.ALIGN_CENTER
Dim codeFont = FontFactory.GetFont(FontFactory.HELVETICA_BOLD, 10)
Dim tagFont = FontFactory.GetFont(FontFactory.HELVETICA_BOLD, 8)
Dim priceFont = FontFactory.GetFont(FontFactory.HELVETICA_BOLD, 11)
codeFont.Color = BaseColor.WHITE
tagFont.Color = BaseColor.WHITE
priceFont.Color = BaseColor.WHITE
itemname.Add(New Chunk(Admin_Menu.Label170.Text, tagFont))
itemprice.Add(New Chunk("P " + Admin_Menu.Label171.Text + ".00", priceFont))
itemcode.Add(New Chunk(Admin_Menu.Label169.Text, codeFont))
Dim pdfCell As New PdfPCell
pdfCell.UseVariableBorders = True
pdfCell.BackgroundColor = BaseColor.RED
pdfCell.BorderColorLeft = BaseColor.BLACK
pdfCell.BorderColorRight = BaseColor.BLACK
pdfCell.BorderColorTop = BaseColor.BLACK
pdfCell.BorderColorBottom = BaseColor.BLACK
pdfCell.PaddingTop = 10
pdfCell.PaddingBottom = 10
pdfCell.PaddingLeft = 8
pdfCell.PaddingRight = 10
pdfCell.AddElement(img)
pdfCell.AddElement(itemname)
pdfCell.AddElement(Barcode2)
pdfCell.AddElement(itemcode)
pdfCell.AddElement(itemprice)
Return pdfCell
End Function

Answer 1

The loop started by
For j As Integer = 0 To Admin_Menu.BarcodePrintListGrid.Rows(i).Cells(5).Value 'Cell quantity to be exported for one item'
executes Admin_Menu.BarcodePrintListGrid.Rows(i).Cells(5).Value + 1 times. You might want to start with the value 1 instead of 0 to get rid of the off-by-one.
The loop started by
For k As Integer = 0 To count Mod 3
executes (count Mod 3) + 1 times.
My first idea was that you might also want to start with the value 1 instead of 0, after all if Count already is a multiple of 3, you don't want it to run at all.
When I set up a simplified version of your program, though, in which I started that loop at 1, I got an exception, too. Thus, I reconsidered the actual purpose of that extra loop (which I myself recommended in my answer to your previous question) and figured out that the number of iterations was completely wrong to start with:
For Count = 1 one needs 2 extra iterations, for Count = 2 one needs 1 extra iteration, for Count = 3 none is needed, for Count = 4 one needs 2 extra iterations, ...
So, one does not need Count Mod 3 iterations of the second loop at all but instead (3 - (Count Mod 3)) Mod 3 iterations, or more simple
While count Mod 3 <> 0
pdfTable.AddCell(emptyCell)
count = count + 1
End While
which also is what intuition should dictate: Continue adding empty cells until the cell count is a multiple of 3...
The test code
I simplified your code to be able to run it at all, after all I don't have those many variables you use. The final version (including the fixes mentioned above, the first loop starting at 1, the second one using the While now) was this:
Public Sub CreateTableLuciferRodstark(filledCells As Integer, fileName As String)
Dim pdfTable As New PdfPTable(3) 'pdfTable Column Count'
pdfTable.DefaultCell.Padding = 3
pdfTable.WidthPercentage = 100
pdfTable.HorizontalAlignment = Element.ALIGN_CENTER
pdfTable.DefaultCell.Border = Rectangle.NO_BORDER
Dim emptyCell As New PdfPCell
emptyCell.Border = 0
Dim count As Integer = 0
For j As Integer = 1 To filledCells
pdfTable.AddCell(create_barcodecell) 'Create a cell with barcode'
count = count + 1
Next
While count Mod 3 <> 0
pdfTable.AddCell(emptyCell)
count = count + 1
End While
Using stream As New FileStream(fileName, 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)
pdfdoc.Close()
End Using
End Sub
Public Function create_barcodecell()
Dim pdfCell As New PdfPCell
pdfCell.UseVariableBorders = True
pdfCell.BackgroundColor = BaseColor.RED
pdfCell.BorderColorLeft = BaseColor.BLACK
pdfCell.BorderColorRight = BaseColor.BLACK
pdfCell.BorderColorTop = BaseColor.BLACK
pdfCell.BorderColorBottom = BaseColor.BLACK
pdfCell.PaddingTop = 10
pdfCell.PaddingBottom = 10
pdfCell.PaddingLeft = 8
pdfCell.PaddingRight = 10
pdfCell.AddElement(New Paragraph("an item"))
pdfCell.AddElement(New Paragraph("a code"))
pdfCell.AddElement(New Paragraph("a price"))
Return pdfCell
End Function
I ran the code for 1 to 6 filled cells:
CreateTableLuciferRodstark(1, "Table1of3.pdf")
CreateTableLuciferRodstark(2, "Table2of3.pdf")
CreateTableLuciferRodstark(3, "Table3of3.pdf")
CreateTableLuciferRodstark(4, "Table4of3.pdf")
CreateTableLuciferRodstark(5, "Table5of3.pdf")
CreateTableLuciferRodstark(6, "Table6of3.pdf")
and the results are:
Table1of3.pdf:
Table2of3.pdf:
Table3of3.pdf:
Table4of3.pdf:
Table5of3.pdf:
Table6of3.pdf: