Subscribe Method (SnapshotChangedEvent)

In This Topic

Subscribe to the SnapshotChangedEvent.

Syntax

C#
Visual Basic (Declaration)

public static SubscriptionToken Subscribe( 
   Action<SnapshotChangedEventArgs> action,
   bool keepSubscriberAlive
)

Public Shared Function Subscribe( _
   ByVal action As Action(Of SnapshotChangedEventArgs), _
   Optional ByVal keepSubscriberAlive As Boolean _
) As SubscriptionToken

Parameters

action: The delegate that gets executed when the event is published.
keepSubscriberAlive: When false the ArcGIS.Core.Events.CompositePresentationEvent<TPayload> will maintain a weak delegate reference to the subscriber. Using a weak delegate reference relieves the subscriber from the need to unsubscribe to enable proper garbage collection.

Return Value

A ArcGIS.Core.Events.SubscriptionToken that uniquely identifies the added subscription.

Example

Subscribe to Location Snapshot event

private void SubscribeToSnapshotEvents()
{
  SnapshotChangedEvent.Subscribe(OnSnapshotChanged);
}
private void OnSnapshotChanged(SnapshotChangedEventArgs args)
{
  if (args == null)
    return;

  var snapshot = args.Snapshot as NMEASnapshot;
  if (snapshot == null)
    return;

  QueuedTask.Run(() =>
  {
    var pt = snapshot.GetPositionAsMapPoint();
    if (pt?.IsEmpty ?? true)
      return;

    // access properties
    var alt = snapshot.Altitude;
    var dt = snapshot.DateTime;
    var vdop = snapshot.VDOP;
    var hdop = snapshot.HDOP;
    // etc

    //TODO: use the snapshot
  });
}

Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

Reference

SnapshotChangedEvent Class
SnapshotChangedEvent Members

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