UpDown. On Lost Focus(EventArgs) Method
Raises the LostFocus event.
protected: override void OnLostFocus(EventArgs ^ e);
protected override void OnLostFocus (EventArgs e);
override this.OnLostFocus : EventArgs -> unit
Protected Overrides Sub OnLostFocus (e As EventArgs)
Raising an event invokes the event handler through a delegate. For more information, see Handling and Raising Events.
The OnLostFocus 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.