An identifier that determines whether the annotation view participates in clustering.
- iOS 11.0+
- macOS 10.13+
- tvOS 11.0+
The default value of this property is
nil, which prevents the annotation view from being clustered with other annotation views. Setting the property to a non
nil value it to participate in clustering.
Clustering occurs when there is a collision between multiple annotation views with the same identifier on the map surface. The annotation views involved in the collision are removed from the map view and replaced by a clustering annotation view, which displays the title from one of the annotations and provides access to the other annotations.