https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.control.previewkeydown?view=netframework-4.8.1&tree=cete.dynamicpdf.viewer.pdfnavigationpanel.previewkeydown
Control.PreviewKeyDown Event (System.Windows.Forms) | Microsoft Learn
Occurs before the KeyDown event when a key is pressed while focus is on this control.
event systemwindows formscontrolmicrosoftlearn