I recently used
iTextSharp to generate few pdfs. The pdfs are stored in a Document Library. I want to setup a search where it searches for and returns any content inside the pdfs. I made a full crawl but that didn't help.
What version of SharePoint? In 2010 you have to add a PDF iFilter (preferably from Foxit Software as the Adobe iFilter is crap).
In 2013 PDFs are crawled natively, you just have to crawl the content.
I am not familiar with iTextSharp, but in order to be crawled there has to be TEXT in the PDF. If you are scanning images into PDF and not performing OCR the contents will not be callable. Some third party products do an OCR pass optionally following scanning. (I see this with ABBY.)