Number of “region” monitored by RegionMonitoring, based on users current location in iOS7

问题

I am working on such a project where apps do the following things:

1. User select a radius (10 meter to 1000 meter) and go to next viewController by pressing "Go" button
2. Here apps Grab users current position and start "region monitoring" based on that current position with selected radius
3. If the user cross that certain boundary (10 meter to 1000 meter) then it gives an "ExitRegion" alert message. And start "region monitoring" again based on users new current position. And the apps keep doing this all the time, both foreground and background mode. I manage to do it & it is working perfectly.

Now, Here I monitor one region, after that another one. So the number is actually one. But I know the maximum number of regions one apps can monitored by "Region Monitoring" is 15. Now my question is in this case should I handle this maximum number of region issue or not? If yes, then how?

One more thing I want to add is, there are some solution of it, which is only work for iOS 6 and earlier. So please let me know if there have some solution of handling number of "region" monitored by "RegionMonitoring", based on users current location in iOS7.

It will be a great pleasure to me if one can give the answer or any suggestion to finish my apps required requirements.

回答1:

If you check the docs, max limit is 20. When you exceed this number, the iOS will release monitoring of the oldest region (think its like its a FIFO queue). Make sure you keep the radius smaller than maximumRegionMonitoringDistance. So in other words you don't need to worry about max limit, you can make sure this by implementing didStartMonitoringForRegion: delegate.

But, If you want to control number of regions being monitored by yourself, you can always stop monitoring a region using stopMonitoringForRegion: You can get a list of regions being monitored with the property monitoredRegions. You can always clear up the region you don't need any more. It's a good practice to keep it minimum as it does effect the battery and app performance.

I'm using following code to clear up all my regions when required.

for (CLCircularRegion *region in self.locationManager.monitoredRegions) {
    [self.locationManager stopMonitoringForRegion:region];
}

But in your case, I would suggest using a constant for Region identifier (e.g. "MY-REGION"), as you cannot monitor two regions with same identifier, adding an other region with the same id removes previously monitored region automatically.

CLCircularRegion *region = [[CLCircularRegion alloc] initWithCenter:coordinate radius:50.0f identifier:@"MY-REGION"];
[self.locationManager startMonitoringForRegion:region];

来源：https://stackoverflow.com/questions/21850536/number-of-region-monitored-by-regionmonitoring-based-on-users-current-locatio