Add a page number in the footer of a PDF file using iText7 and ASP.NET C#

Question

I can create a pdf file using iText7 and C# ASP.NET

This pdf file contains 9 pages total.

I have tried to add in my code the total number of pages and a dotted line

But I have two problems

1. the number of pages (1 of 9, 2 of 9, 3 of 9...) are showing only in the pages number 8 and number 9 in the PDF file
2. the dotted line don't showing in page number one...

Any help would greatly appreciate... Thank you.

My code below

private void mtpdfnew()
{
    DataTable dt = new DataTable();

    filename = @"C:\inetpub\wwwroot\public\pdf\" +
        DateTime.Now.ToString("yyyyMMddHHmmss") + ".pdf";

    PdfWriter writer = new PdfWriter(filename);
    PdfDocument pdf = new PdfDocument(writer);
    Document document = new Document(pdf);

    using (MySqlConnection myConnectionString =
       new MySqlConnection(ConfigurationManager.ConnectionStrings["cn"].ConnectionString))
    {
        using (MySqlCommand cmd =
            new MySqlCommand("SP", myConnectionString))
        {
            cmd.Connection.Open();
            cmd.CommandType = CommandType.StoredProcedure;

            using (MySqlDataAdapter da =
                new MySqlDataAdapter(cmd))
            {
                da.Fill(dt);

                if (dt.Rows.Count > 0)
                {
                    for (int i = 0; i < dt.Rows.Count; i++)
                    {
                        contents = new Paragraph(dt.Rows[i]["contents"].ToString())
                            .SetTextAlignment(TextAlignment.JUSTIFIED)
                            .SetFontSize(12);

                        if (dt.Rows[i]["contents"].ToString().StartsWith("Set") && i != 0)
                        {
                            document.Add(new AreaBreak(AreaBreakType.NEXT_PAGE));
                            document.Add(new LineSeparator(new DottedLine(1, 2)).SetMarginTop(4));
                        }

                        List<IElement> lst = HtmlConverter.ConvertToElements(dt.Rows[i]["contents"].ToString()).ToList();

                        for (int j = 0; j < lst.Count; j++)
                        {
                            IBlockElement element = (IBlockElement)lst[j];

                            if (dt.Rows[i]["contents"].ToString().StartsWith("Set"))
                            {
                                contents.SetFontSize(12)
                                    .SetBold()
                                    .SetFontColor(ColorConstants.BLUE);
                            }
                            else if (dt.Rows[i]["contents"].ToString().StartsWith("- "))
                            {
                                contents.SetFontSize(10)
                                    .SetBold()
                                    .SetFontColor(ColorConstants.BLACK);
                            }
                            else
                            {
                                contents.SetTextAlignment(TextAlignment.JUSTIFIED_ALL)
                                    .SetFontSize(10)
                                    .SetFontColor(ColorConstants.BLACK);

                            }

                            element.SetProperty(Property.LEADING, new Leading(Leading.MULTIPLIED, -1f));
                            document.Add(element);
                        }
                    }

                    Footer footerHandler = new Footer();
                    pdf.AddEventHandler(PdfDocumentEvent.END_PAGE, footerHandler);
                    footerHandler.WriteTotal(pdf);
                    dest = filename.ToString();
                    document.Close();
                }

                Response.Clear();
                Response.ContentType = "application/pdf";
                Response.AppendHeader("Content-Disposition", "attachment; filename=" + dest);
                Response.TransmitFile(dest);
                Response.End();
            }
        }
    }
}

private class TableFooterEventHandler : IEventHandler
{
    private Table table;

    public TableFooterEventHandler(Table table)
    {
        this.table = table;
    }

    public void HandleEvent(Event currentEvent)
    {
        PdfDocumentEvent docEvent = (PdfDocumentEvent)currentEvent;
        PdfDocument pdfDoc = docEvent.GetDocument();
        PdfPage page = docEvent.GetPage();

        int pageNumber = pdfDoc.GetPageNumber(page);
        Rectangle pageSize = page.GetPageSize();

        PdfCanvas canvas = new PdfCanvas(page.NewContentStreamBefore(), page.GetResources(), pdfDoc);
        new Canvas(canvas, new Rectangle(36, 20, page.GetPageSize().GetWidth() - 72, 50))
            .Add(table)
            .Close();
    }
}

protected class Footer : IEventHandler
{
    protected PdfFormXObject placeholder;
    protected float side = 20;
    protected float x = 300;
    protected float y = 25;
    protected float space = 4.5f;
    protected float descent = 3;

    public Footer()
    {
        placeholder = new PdfFormXObject(new Rectangle(0, 0, side, side));
    }

    public virtual void HandleEvent(Event @event)
    {
        PdfDocumentEvent docEvent = (PdfDocumentEvent)@event;
        PdfDocument pdf = docEvent.GetDocument();
        PdfPage page = docEvent.GetPage();
        int pageNumber = pdf.GetPageNumber(page);
        Rectangle pageSize = page.GetPageSize();

        PdfCanvas pdfCanvas = new PdfCanvas(page);
        Canvas canvas = new Canvas(pdfCanvas, pageSize);
        canvas.SetFontSize(10);

        Paragraph p = new Paragraph()
            .Add("Page ")
            .Add(pageNumber.ToString())
            .Add(" of");

        canvas.ShowTextAligned(p, x, y, TextAlignment.RIGHT);
        canvas.Close();

        pdfCanvas.AddXObjectAt(placeholder, x + space, y - descent);
        pdfCanvas.Release();
    }

    public void WriteTotal(PdfDocument pdfDoc)
    {
        Canvas canvas = new Canvas(placeholder, pdfDoc);
        canvas.SetFontSize(10);
        canvas.ShowTextAligned(pdfDoc.GetNumberOfPages().ToString(),
            0, descent, TextAlignment.LEFT);
        canvas.Close();
    }
}

private class TableHeaderEventHandler : IEventHandler
{
    private Table table;
    private float tableHeight;
    private Document doc;

    public TableHeaderEventHandler(Document doc)
    {
        this.doc = doc;
        InitTable();

        TableRenderer renderer = (TableRenderer)table.CreateRendererSubTree();
        renderer.SetParent(new DocumentRenderer(doc));

        LayoutResult result = renderer.Layout(new LayoutContext(new LayoutArea(0, PageSize.A4)));
        tableHeight = result.GetOccupiedArea().GetBBox().GetHeight();
    }

    public void HandleEvent(Event currentEvent)
    {
        PdfDocumentEvent docEvent = (PdfDocumentEvent)currentEvent;
        PdfDocument pdfDoc = docEvent.GetDocument();
        PdfPage page = docEvent.GetPage();
        int pageNum = docEvent.GetDocument().GetPageNumber(page);
        PdfCanvas canvas = new PdfCanvas(page.NewContentStreamBefore(), page.GetResources(), pdfDoc);
        PageSize pageSize = pdfDoc.GetDefaultPageSize();
        float coordX = pageSize.GetX() + doc.GetLeftMargin();
        float coordY = pageSize.GetTop() - doc.GetTopMargin();
        float width = pageSize.GetWidth() - doc.GetRightMargin() - doc.GetLeftMargin();
        float height = GetTableHeight();

        Rectangle rect = new Rectangle(coordX, coordY, width, height);

        new Canvas(canvas, rect)
            .Add(table)
            .Close();
    }

    public float GetTableHeight()
    {
        return tableHeight;
    }

    private void InitTable()
    {

    }
}

Answer 1

You add the footer drawing event handler to the document just before closing the document:

Footer footerHandler = new Footer();
pdf.AddEventHandler(PdfDocumentEvent.END_PAGE, footerHandler);
footerHandler.WriteTotal(pdf);
dest = filename.ToString();
document.Close();

At that time nearly all pages already are finished and the END_PAGE events for them have been triggered and processed, so your footer handler won't receive them. Only the last and probably the previous page still are to be finished, so your footer handler will be called for them.

So, to have your footer handler receive the END_PAGE events for all pages, create and register it early, right after creating the pdf document:

PdfWriter writer = new PdfWriter(filename);
PdfDocument pdf = new PdfDocument(writer);
Footer footerHandler = new Footer();
pdf.AddEventHandler(PdfDocumentEvent.END_PAGE, footerHandler);
Document document = new Document(pdf);

Writing the total, of course, still must be done at the end:

footerHandler.WriteTotal(pdf);
dest = filename.ToString();
document.Close();