property PageCount; // forwards to underlying TPdf
Mirrors TPdf.PageCount. The TPdfView component forwards the call to its underlying Pdf instance and refreshes the view if the call mutates the document.
All semantic notes from TPdf.PageCount apply identically here; the only difference is that you address the operation through the visual control instead of the model object.
When TPdfView is bound to an external TPdf (assigning PdfView1.Pdf := Pdf1), reading this member returns the same data as Pdf1.PageCount; when TPdfView owns its internal TPdf, this member is the only public accessor.
UpdatePage on the view; setting them through the underlying TPdf does not — remember to call PdfView1.UpdatePage manually in that case.PdfView1.Active is False.
if PdfView1.Active then
Memo1.Lines.Add('PageCount = ' + VarToStr(PdfView1.PageCount));