https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.control.dpichangedafterparent?view=netframework-4.8.1&tree=cete.dynamicpdf.viewer.pdfnavigationpanel.dpichangedafterparent
Control.DpiChangedAfterParent Event (System.Windows.Forms) | Microsoft Learn
Occurs when the DPI setting for a control is changed programmatically after the DPI of its parent control or form has changed.
event systemwindows formscontrolmicrosoftlearn