TOPIC:

This is a performance issue. the method Global.hideAnot() works only if I closed the pdf and opened it again,

Hi,
we are verifying how to resolve your request.

Hi,
we have done some further tests...

If you call hideAnnots(true); in the Init() method (before the pdf rendering) this will have effect and you will hide all the annots.
If you want to change this dinamically, you need to rerender the page where you are.

If you want to hide a specific annot, you need to call annot.SetHide(boolean hide) and re-render the page.