The initialize method should be called in your application start-up (such as main(), OnAppStart(), DLLMain(), etc. - depending on our application type and development platform).

In case you don't have such a start-up method, you can call initialize multiple times and PDFNet will make sure that it is initialized only once. You only need to make sure that it is called before any other PDFNet method.

Once initialized, be sure to lock the document when working in a multi-threaded environment.