.NET events are actions triggered on a .NET object that send event-specific data to the .NET container. To use these events in LabVIEW, register for the event and handle it with a callback VI.

Actions taken on a .NET object include interactions like the following:

  • Clicking a mouse
  • Pressing a key
  • Receiving notifications about things such as running out of memory or tasks completing

Whenever these actions occur to the object, the object sends both of the following:

  • An event to alert the .NET container
  • Event-specific data. The .NET object defines the events available for an object.

To use .NET events in a LabVIEW application, you must do both of the following:

  1. Register for the event
  2. Handle the event when it occurs

.NET event registration in LabVIEW is similar to dynamic event registration for a LabVIEW Event structure. However, the architecture of a .NET event VI is different from the architecture of an event-handling VI. A typical .NET event VI comprises the following components:

  • .NET object for which you want to generate an event.
  • Register Event Callback function to specify and register for the type of event you want to generate. The Register Event Callback function is a growable node capable of handling multiple events, similar to the Register For Events function.

    Wiring a .NET object to the Register Event Callback function and specify the event you want to generate for that object is what registers the .NET object for that event.

  • Callback VI that contains the code you write to handle the event you specify.

    Different events might have different event data formats so changing the event after you create a callback VI might break wires on the block diagram. Select the event before you create the callback VI.

For specific steps on registering for and handling .NET events, see Registering and Handling .NET and ActiveX Events.

.NET (Core) Considerations

LabVIEW does not support .NET (Core) controls.

.NET Framework Considerations

You can handle events on .NET Framework controls in a container. For example, you can place a calendar control in a .NET Framework container and specify that you want to handle a DoubleClick event for the items displayed in the calendar.