OnKeyDown event

Fires when a key is pressed while the control has focus. The Sender parameter references the TPdfView instance that raised the event, so a single handler can serve several views by inspecting Sender

Typical uses include intercepting arrow keys / Page Up / Page Down to drive navigation, Ctrl+F to open a search dialog, or Escape to clear a selection. Because the handler runs on the VCL main thread, you can update form controls and call other VCL APIs directly

Handlers should return promptly, because PDFium rendering and form filling occur on the same thread, and any delay here pushes back the next page repaint

• Set TabStop to True if you want this control to take part in tab-key focus traversal so that keyboard events are delivered
• When you assign this event at design time the IDE generates a stub procedure on the form; you can also assign it at run time with PdfView1.OnKeyDown := MyHandler
• Combine it with the matching Set Cursor / Set Caret calls on TPdfView to keep visual feedback in sync