"Page" is the page which is currently visible first in the window.
Although the API is using mostly(*) 0 based page numbers, Page uses "1" for the first page. This was necessary for compatibility to Version 2.
(*)WPViewPDF 3 also uses 1 based page numbers for the page ranges (PrintPages) and also when specifieg a page range as string, i.e. "1,5,7-12". Ths is useful since You can pass the user input directly to the engine.
I'm using WpViewPDF 3 registered edition and it works fine, except the following little problem.
I do not understand how ViewPDF1.Page and ViewPDF1.PageCount work. I tried to copy the code from the shipped Delphi PDFView demo to display the current page in a TEdit component. When the PDF is loaded with LoadFromStream, WpViewPDF displays the first page and returns 0 for the current page number. If I scroll down the page a bit (without displaying the second page), it immediately says "1". Same problem in the demo.
