Passing a parameter to an overridden OnEndPage method

Question

I need to pass a parameter to an overridden version of the "OnEndPage" method, when i declare the parameter i don't get any error but when i call the method it tells me that "cannot implicitly convert void to itextsharp.text.pdf.ipdfpageevent"

This is my OnEndPage method:

  public class pdfPage : iTextSharp.text.pdf.PdfPageEventHelper
{           
    public override void OnEndPage(PdfWriter writer, Document doc, int parametro)
    {
        PdfPTable headerTbl = new PdfPTable(1);

        headerTbl.TotalWidth = doc.PageSize.Width;

        Image logo = Image.GetInstance("logo.png");

        logo.ScalePercent(42);

        PdfPCell cell = new PdfPCell(logo);

        cell.HorizontalAlignment = Element.ALIGN_LEFT;

        cell.PaddingRight = 52;

        cell.Border = 0;

        headerTbl.AddCell(cell);

        headerTbl.WriteSelectedRows(0, -1, 0, (doc.PageSize.Height - 10), writer.DirectContent);

        PdfPTable headerrow = new PdfPTable(7);
        headerrow.TotalWidth = 570f;
        headerrow.LockedWidth = true;
        headerrow.AddCell(new Phrase("TIPO DOCUMENTO", new Font(Font.FontFamily.HELVETICA, 6f)));

        headerrow.WriteSelectedRows(0, -1, 0, (doc.PageSize.Height - 50), writer.DirectContent);
    }
}

and this is how i am calling it:

 var doc = new Document(PageSize.A4, 10, 10, 170, 10);
        pdfPage page = new pdfPage();
        PdfWriter pdfWriter = PdfWriter.GetInstance(doc, new FileStream( "test.pdf", FileMode.Create));
        pdfWriter.PageEvent = page.OnEndPage(pdfWriter, doc, 1234);

Answer 1

To further add to what Bruno said, if you want to add additional information to your PdfPageEventHelper you can just add additional properties:

public class pdfPage : iTextSharp.text.pdf.PdfPageEventHelper
{           
    public int parametro { get; set; }
    public override void OnEndPage(PdfWriter writer, Document doc)
    {
        //...
    }
}

And then:

var page = new pdfPage();
page.parametro = 40;
pdfWriter.PageEvent = page;

Or just:

pdfWriter.PageEvent = new pdfPage() { parametro = 40 };

If you want to change this valid "per page", you're going to need to move your logic into this class instead of the calling body.