ios - 一次触发具有不同半径 CLCircularRegion 的基于位置的通知

Question

我想向用户显示 3 个不同的本地通知，因为他即将到达准确点。所以我设置了3个圆心相同但半径不同的圆形区域(500m，1km，2km)。当我接近这一点时，我会同时收到所有 3 条通知。为什么会这样？我下面的代码是不是做错了什么，或者它只是来自 Apple 的功能，显示更多区域通知以消耗更少的电池？我可以用其他方式做到这一点吗(当用户接近某个点时提醒他？

func createLocalNotification(id: String, title: String, body: String, center: CLLocationCoordinate2D, radius: CLLocationDistance, repeats: Bool) {
    let notificationCenter = UNUserNotificationCenter.current()

    let content = UNMutableNotificationContent()
    content.title = title
    content.body = body
    content.sound = UNNotificationSound.default()

    let region = CLCircularRegion(center: center, radius: radius, identifier: id)
    region.notifyOnEntry = true
    region.notifyOnExit = false
    let trigger  = UNLocationNotificationTrigger(region: region, repeats: repeats)

    let request = UNNotificationRequest(identifier: id, content: content, trigger: trigger)
    notificationCenter.add(request) { (error) in
        if let error = error {
            print("Uh oh! We had an error: \(error)")
        }
    }
}

Answer 1

确保在测试应用时考虑以下因素:

When testing your region monitoring code in iOS Simulator or on a device, realize that region events may not happen immediately after a region boundary is crossed. To prevent spurious notifications, iOS doesn’t deliver region notifications until certain threshold conditions are met. Specifically, the user’s location must cross the region boundary, move away from the boundary by a minimum distance, and remain at that minimum distance for at least 20 seconds before the notifications are reported.

The specific threshold distances are determined by the hardware and the location technologies that are currently available. For example, if Wi-Fi is disabled, region monitoring is significantly less accurate. However, for testing purposes, you can assume that the minimum distance is approximately 200 meters.

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