เมธอด SelectionRanges

The selection members expose the same page and character-index model used by viewer selection painting. Calls validate page numbers and character ranges before changing the selection

Programmatic selection works independently of user input options, then repaints the viewer and raises OnSelectionChange through the normal selection pipeline

• API names, type names, and PDF terms keep their original spelling so code search remains reliable
• Call the member only after the owning document or viewer is active unless the syntax describes an event or design-time property