如何在同一个 pdf 文档中创建 pdf 的相同副本

Question

IN my program user passes the input as number of copies.

So if user passes number of copies as 2 then i want to generate single pdf document with same pages repeating twice

I am using PdfSharp library

I have below code which creates pdf document with multiple pages

var document = new PdfDocument();
var page = document.AddPage();
var gfx = XGraphics.FromPdfPage(page);
page.Width = XUnit.FromMillimeter(111);
page.Height = XUnit.FromMillimeter(222);
//some logic to create multiple pages
document.Save("C:\mydoc\");

I am sure we need to add loop but what more i need to do to have same copies repeating in same document as per input provided

Update

Lets say document generated 2 pages and user says number of copies 2 then that single pdf document will now have 4 page with 2 pages repeating twice in same document:

pagecontent1 pagecontent 2, pagecontent1,pagecontent2

Update 2

i tried @Christophers solution and changed code like below before i save document

PdfDocument outputDocument = new PdfDocument();
for (int i = 0; i < PageCopies; i++)
        {
            //the loop doing the copies
            for (int k = 0; k < document.Pages.Count; k++)
            {
                outputDocument.Pages.Add(document.Pages[k]);

            }
        }

But now i get error a pdf document must be opened with pdfdocumentopenmode.import to import pages from it

Answer 1

If I understand correctly, I think you could save your original Complete PDF, then open and merge it multiple times.

If that is so, this may be close. I've combined your code with some documentation from pdfsharp found here: http://www.pdfsharp.net/wiki/ConcatenateDocuments-sample.ashx

var document = new PdfDocument();
var page = document.AddPage();
var gfx = XGraphics.FromPdfPage(page);
page.Width = XUnit.FromMillimeter(111);
page.Height = XUnit.FromMillimeter(222);
//some logic to create multiple pages
document.Save("OriginalDoc.pdf");

//Logic here to open and merge the document multiple times
PdfDocument outputDocument = new PdfDocument();

// Open the document to import pages from it.
PdfDocument inputDocument = PdfReader.Open("C:\mydoc\OriginalDoc.pdf", PdfDocumentOpenMode.Import);

  for(int i = 0; i < Copies; i++)
  {
    // Iterate pages
    int count = inputDocument.PageCount;
    for (int idx = 0; idx < count; idx++)
    {
      // Get the page from the external document...
      PdfPage page = inputDocument.Pages[idx];
      // ...and add it to the output document.
      outputDocument.AddPage(page);
    }
  }
  // Save the document...
  const string filename = "MergedDoc.pdf";
  outputDocument.Save(filename);

I suspect this could be done without saving and re-opening the document as well, but I haven't used pdfsharp myself.

Answer 2

Okay, the propblem turned out to be very different from what I first understood. As I have no expierience with PDFSharp in particular, I can only help with the general loop structure.

//I use a array to simulate the input PDF
int[] input = new int[]{ 1, 2 };
//And a list to simulate the output PDF
List<int> output = new List<int>();

//PageCopies is set somewhere outside this code.
//The loop counting the copies
for(int i = 0; i < PageCopies; i++){
  //the loop doing the copies
  for(int k = 0; k < input.Count; k++){
    output.Add(input[k]);
  }
}

Dislcaimer: Code not run against a compiler. Syntax and off by one errors reserved

Answer 3

Finally i managed to resolve myself but offcourse due to clues from @Christopher and @Blaise. Here is my final code

var document = new PdfDocument();
var page = document.AddPage();
var gfx = XGraphics.FromPdfPage(page);
page.Width = XUnit.FromMillimeter(111);
page.Height = XUnit.FromMillimeter(222);
//some logic to create multiple pages
 document.Save("C:\mydoc\");

PdfDocument finalOutputDocument;
        if (CopyCount >1)
        {
            MemoryStream stream = new MemoryStream();
            document.Save(stream, false);
            PdfDocument source = PdfReader.Open(stream, PdfDocumentOpenMode.Import);

            finalOutputDocument= new PdfDocument();

            for (int i = 0; i < CopyCount; i++)
            {
                for (int k = 0; k < document.Pages.Count; k++)
                {
                    finalOutputDocument.Pages.Add(source.Pages[k]);
                }
            }
        }
        else
        {
            finalOutputDocument= document;
        }

        finalOutputDocument.Save(path);