You won’t be able to do this as easily with WinForms since it expects a PDFViewWPF view object.
A solution that should work for both WinForms and WPF is overriding the OnMouseUp(MouseEventArgs) event. The PDFViewCtrl exposes the ability to control what happens when a user right clicks which would allow you to disable what is showed to a user:
We have some discussion on this for one of our older community posts: