Table of Contents
Table of Contents
Modify PDF Files

To modify a PDF file, you must load it to a PdfDocument object first, then use any API available to PdfDocument to modify the document.

The following code load a PDF file, append a new page and then save it with a different name:

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//Load the file        
PdfDocument doc = new PdfDocument(pdfFileName);

//Append a new page
PdfPage page = doc.Pages.Add();

//Render contents on the new page
HtmlToPdf.ConvertHtml("Text on the new page.", page);

//Save it to a new file
doc.Save(newFileName);

You can also modify existing pages. The following code overlays additional text on the first page:

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//Load the file        
PdfDocument doc = new PdfDocument(pdfFileName);

//Get the first page
PdfPage page = doc.Pages[0];

//Render contents on the page
HtmlToPdf.ConvertHtml("Overlay text", page);

//Save it to a new file
doc.Save(newFileName);