property Rotation: TRotation;
Visual rotation applied to the rendered page (ro0 / ro90 / ro180 / ro270).
Does not modify the underlying PDF; use TPdf.PageRotation to change persistent rotation.
All TPdfView display properties trigger a repaint when assigned; you can change several in sequence without flicker because the redraw is coalesced into a single invalidation.
Active := True.PdfView1.Pdf at runtime, re-apply any view-only settings — the new TPdf has its own state.
begin
PdfView1.Rotation := {value};
PdfView1.Active := True;
end;