Gets or sets whether an event was handled, if it was handled the default actions are not required.
NuGet Package: DevExpress.Win.Scheduler
true if it was handled and the default dialog doesn’t need to be shown; otherwise, false.
If the event parameter’s Handled property is set to true within a handler, then the default dialog will not be shown. Otherwise, the default dialog will be shown in any case after any custom actions present have been performed within the event handler.