为什么定位服务不能用作后台任务？

Question

In my app there is a location (area) to be watched. When the device is moved away from that location (it could be a distance as small as 5 - 10 meters) an AlertView pops up and a sound is played. When the app is in the background an local notification is generated. Tapping or sliding the notification brings the app to the front. This works fine. However, when running in the background the location updates stoppes after 15-16 minutes or so. The arrow is removed from the status bar. Bringing the app to the front the AlertView pops up and the sound is played. As far as I can see is location services getting a new fix on the current position and is the AlertView shown because the initial distance is greater then the area to be watched. Due to the small areas to be watched I think I could not use "significant-changes" or "didExitRegion". Is that true?

I set the tag in the info.plist to "App registers for location updates" in "required background modes".

Is there anyone out there who has a clou about what's goiing on? Do I have to put some code in - (void)applicationDidEnterBackground:(UIApplication *)application {} and if so.... what should that be?

Thanks in advance,

Regards,

Adri

Answer 1

在startUpdatingLocation之前，您可以为所需的精度设置CLLocationManager的requiredAccuracy和distanceFilter字段