A GUI for .NET, event-driven application blocks for input and processes events as they are received. ABL supports several event models, including the use of triggers and call-backs for handle-based objects, and the use of class events for class-based objects.
The main communication between .NET and ABL is the invocation of ABL event handlers. These event handlers are associated with specific .NET events. .NET forms and controls fire events when an action occurs. ABL allows you to subscribe and unsubscribe event handler methods or procedures to .NET control events.