UNLocationNotificationTrigger
A trigger condition that causes the system to deliver a notification when the user’s device enters or exits a geographic region you specify.
Declaration
class UNLocationNotificationTriggerOverview
Create a UNLocationNotificationTrigger object when you want to schedule the delivery of a local notification when the device enters or leaves a specific geographic region. The system limits the number of location-based triggers that it schedules at the same time.
When configuring the region, use the notifyOnEntry and notifyOnExit properties to specify whether you want the system to deliver notifications on entry, on exit, or both. Listing 1 shows the creation of a trigger that fires only once when the user’s device enters a circular region with a 2-kilometer radius.
Listing 1. Creating a location-based trigger
The system doesn’t immediately trigger region-based notifications when the edge of the boundary is crossed. The system applies heuristics to ensure that the boundary crossing represents a deliberate event and isn’t the result of spurious location data. For more information about the heuristics, see Monitoring the user’s proximity to geographic regions.