https://learn.microsoft.com/pt-pt/dotnet/api/system.windows.forms.control.onvalidating?view=netframework-4.8.1&viewFallbackFrom=windowsdesktop-10.0
Control.OnValidating(CancelEventArgs) Method (System.Windows.Forms) | Microsoft Learn
Raises the Validating event.
windows formscontrolmethodsystemmicrosoft