使用iTextSharp在多个pdf页面上构造标题

Question

I'm generating a PDF file based on a record selected in my datagridview. It will consist of 3-5 pages. I created a table with 2 columns to represent my header. the first cell is left aligned and the 2nd cell is right aligned. I want this same inforamtion displayed on all pages.

After doing some googling, I saw a header.WriteSelectedRows() property which is supposed to help with that? One example was :

header.WriteSelectedRows(0, -1, doc.PageSize.GetLeft(5), doc.PageSize.GetTop(5), wri.DirectContent);

2nd was:

 header.WriteSelectedRows(0, -1, doc.LeftMargin, doc.PageSize.Height - 36, wri.DirectContent);

However both resulted in just the first page having the table/header. Any ideas on what I need to fix? Thanks!

Code:

 PdfPTable header = new PdfPTable(2);
 header.HorizontalAlignment = Element.ALIGN_LEFT;
 header.TotalWidth = doc.PageSize.Width - 20f;
 header.LockedWidth = true;
 Phrase cell1 = new Phrase(signal.ProformaType);
 Phrase cell2 = new Phrase("text" + Environment.NewLine + "text"
     + Environment.NewLine + signal.Signal);

 PdfPCell c1 = new PdfPCell(cell1);
 c1.Border = iTextSharp.text.Rectangle.NO_BORDER;
 c1.VerticalAlignment = iTextSharp.text.Element.ALIGN_TOP;
 c1.HorizontalAlignment = iTextSharp.text.Element.ALIGN_LEFT;
 header.AddCell(c1);

 PdfPCell c2 = new PdfPCell(cell2);
 c2.Border = iTextSharp.text.Rectangle.NO_BORDER;
 c2.VerticalAlignment = iTextSharp.text.Element.ALIGN_TOP;
 c2.HorizontalAlignment = iTextSharp.text.Element.ALIGN_RIGHT;             
 header.AddCell(c2);
 header.WriteSelectedRows(0, -1, doc.LeftMargin, doc.PageSize.Height - 36, wri.DirectContent);

Answer 1

The PdfPTable is added to the first page only because you are adding it to the first page only. If you want to add it to every page that is created by iText, you shouldn't add the PdfPTable where you are adding it now.

Instead you should add it in the OnEndPage() method of a page event. This is explained in answers to questions such as:

• How can I add Header and footer in pdf using iText in java?
• how to add an image to my header in iText generated PDF?
• How to handle the case in wich an iText\\iTextSharp table is splitted in two pages?
• ...

In other words, you need to create your own implementation of the PdfPageEvent interface. The best way is to extend the PdfPageEventHelper class:

public class MyPageHeader : PdfPageEventHelper
{

    PdfPTable header = ... // define header table here        

    public override void OnEndPage(PdfWriter writer, Document document)
    {
        header.WriteSelectedRows(0, -1, document.Left, document.Top, writer.DirectContent);
    }
}

To make this work, you need to declare this page event before opening the Document :

PdfWriter pdfWriter = PdfWriter.GetInstance(document, pdfFileStream);
pdfWriter.PageEvent = new MyPageHeader();
document.Open();  

Now, every time a new page is created, the header will be added automatically.

You may want to adapt document.Left and document.Top in the code above, because right now, it will add the table in the upper-right corner of each page, you may want to use document.Left + 36 and document.Top - 5 or something like that.

Also: make sure that there is sufficient room for the header, otherwise your header will overlap with the content you are adding straight to the Document using document.Add() . You can change the margins in the constructor of the Document class.