title: How to update a PDF object in C# using iTextSharp?
body: <p>I'm working with iTextSharp to read all the hyperlinks from a PDF document, but I also need to change their value. I'm getting all the objects of the PDF using a for loop and with that I can access to all of them, this is the code in PDF document:</p>
  
  <pre><code>74 0 obj&lt;&lt;/F 75 0 R/S/Launch&gt;&gt;
  endobj
  75 0 obj(../documents/referenced_document.html)
  endobj
  76 0 obj&lt;&lt;/F 77 0 R/S/Launch&gt;&gt;
  endobj
  </code></pre>
  
  <p>And this is my code in C# to read the PDF Object:</p>
  
  <pre><code>PdfString pdfString = (PdfString)objectItem;
  string innerText = pdfString.ToString();
  </code></pre>
  
  <p>My question is, how can I change the PsfString value that I get in the innerText string?
  I've searched in the properties and methods of the PdfString and PdfObject classes,  but I can't find something that allow me to do that.</p>
  
  <p>Does somebody know how to do that?</p>