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Home » Newsletter » November 2007

By Raju Sinha

Document properties of a PDF file include metadata such as document information, document restrictions, and font information.

This metadata, which contains precise information about the whole document, can be extracted by applications (such as file indexing services, search engine spiders, and PDF viewers and printers). Document properties can also be easily read by humans.

In previous articles, you learned about using PDFOne .NET to read and change some of these documentation properties. In this article, you will learn about how to change document information properties such as title, author, subject, and keywords.

To read the document information properties of a PDF document, you need to first load the document using an object of the PDFDocument class and then access the PDFDocument.DocInfo property.

// Create a new document object
PDFDocument doc = new PDFDocument();
 
// Load an existing PDF document
doc.Load("existing_doc.pdf");

// Display document information properties
Console.WriteLine(doc.DocInfo.Title);
Console.WriteLine(doc.DocInfo.Author);
Console.WriteLine(doc.DocInfo.Subject);
Console.WriteLine(doc.DocInfo.Keywords);
Console.WriteLine(doc.DocInfo.Creator);

Console.ReadLine(); // Press Return key to continue

The PDFDocument.DocInfo property is an object of the PDFDocInfo class. It allows you to set or get document information properties of the loaded PDF document. In the code snippet below, we modify the document information properties.

...
 
// Modify document information properties
doc.DocInfo.Title = "To Be Or Not To Be";
doc.DocInfo.Subject = "Hamlet's Immortal Dilemma";
doc.DocInfo.Author = "Raju Sinha";
doc.DocInfo.Keywords = 
  "hamlet, shakespeare, dilemma, english, drama, play";
doc.DocInfo.Creator = 
  "Gnostice PDFOne .NET component library";

// Save changes
doc.OpenAfterCreate = true;
doc.Save("modified_doc.pdf");
doc.Close();