SpatialEntity.TryGetGuid

bool TryGetGuid(Guid& guid)

A durable identifier for this entity that stays the same across sessions and device reboots! Entities only have one once they’re persisted, either by the system itself, or by a call to Persist. Store it, and pass it to FindAnchor to get the same physical entity back in a later session.


Guid& guid	The entity’s persistent identifier, `Guid.Empty` if it has none.
RETURNS: bool	False if this entity has no persistence component.

Examples

Keeping track of anchors by Guid

For apps that keep anchors in their own save data instead of by name. The Guid arrives a moment after Persist, so watch for it.

List<Guid> savedAnchors = new List<Guid>();

public void StepSavedAnchors()
{
	foreach (SpatialEntity anchor in SpatialEntity.With(SpatialComponent.Anchor))
	{
		if (anchor.HasChanged(SpatialComponent.Persistence) && anchor.TryGetGuid(out Guid guid))
			savedAnchors.Add(guid);
	}

	// Storage no longer having a Guid shows up as Failed
	foreach (SpatialEntity anchor in SpatialEntity.Removed)
	{
		if (anchor.Status == SpatialStatus.Failed && anchor.TryGetGuid(out Guid lost))
			savedAnchors.Remove(lost);
	}
}

// In a later session, each Guid loads back into its anchor
public List<SpatialEntity> RestoreAnchors()
{
	List<SpatialEntity> result = new List<SpatialEntity>();
	foreach (Guid guid in savedAnchors)
		result.Add(SpatialEntity.FindAnchor(guid));
	return result;
}

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