protected virtual void OnFieldEnter(FieldEventArgs e)

Protected Overridable Sub OnFieldEnter(e As FieldEventArgs)

Raising an event invokes the event handler through a delegate.

The OnFieldEnter method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Notes to Inheritors:

When overriding OnFieldEnter in a derived class, be sure to call the base class's OnFieldEnter method so that registered delegates receive the event.