property OnResize: TNotifyEvent;
Fired whenever the control's client area changes size. The Sender parameter references the TPdfView instance that raised the event, so a single handler can serve multiple views by inspecting Sender.
Typical uses include: re-fit the page (e.g. invoke Zoom(pfmFitWidth)) or reposition floating toolbars. Because the handler runs on the VCL main thread, you can update form controls and call other VCL APIs directly.
Handlers must return quickly — PDFium rendering and form filling occur on the same thread, and any delay here postpones the next page repaint.
TabStop to True if you want this control to participate in tab-key focus traversal so that keyboard events are delivered.PdfView1.OnResize := MyHandler.Set Cursor / Set Caret calls on TPdfView to keep visual feedback synchronized.
procedure TForm1.PdfViewOnResize(Sender: TObject);
begin
// re-fit the page (e.g. invoke Zoom(pfmFitWidth)) or reposition floating toolbars
Caption := Format('OnResize on page %d', [PdfView1.PageNumber]);
end;