https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.control.causesvalidation?view=netframework-4.8.1&tree=cete.dynamicpdf.viewer.pdfnavigationpanel.causesvalidation
Control.CausesValidation Property (System.Windows.Forms) | Microsoft Learn
Gets or sets a value indicating whether the control causes validation to be performed on any controls that require validation when it receives focus.
property systemwindows formscontrolmicrosoftlearn