Show and hide existing annotations in Xamarin

By default, PDFViewCtrl shows all annotations on PDF document. If you want to hide a particular annotation on PDFViewCtrl, or hide all annotations on PDFViewCtrl, you can hide annotations as follows:

To show a hidden annotation in PDFViewCtrl, call ShowAnnotation:

void ShowAnnotation(PDFViewCtrl pdfViewCtrl, Annot annot, int annotPageNum) {
  pdfViewCtrl.ShowAnnotation(annot);
  pdfViewCtrl.Update(annot, annotPageNum);
}

To hide an annotation in PDFViewCtrl, call HideAnnotation.

void HideAnnotation(PDFViewCtrl pdfViewCtrl, Annot annot, int annotPageNum) {
  pdfViewCtrl.HideAnnotation(annot);
  pdfViewCtrl.Update(annot, annotPageNum);
}

Alternatively, you can show/hide all annotations in PDFViewCtrl by calling setDrawAnnotations(boolean). This method toggles the visibility of annotations and form fields.

For example, disabling all annotations and form fields from rendering:

pdfViewCtrl.SetDrawAnnotations(false);
pdfViewCtrl.Update(true);