How to calculate current location in WatchKit extension

问题

How to calculate the current user location in Watch Kit extension as we can't use CoreLocation in watch kit.

Thanks in advance

回答1:

You can use CoreLocation in your watch app extension very similarly to how you use it in your iPhone app. The key difference is that a user can't authorize your extension to have access to Core Location. They will need to do that from your iPhone app. So you will need to check if the user has authorized location services for your app and if they haven't, you will need to instruct them how to do it.

Here is the code I use in my watch kit extension for tracking the current location. (GPWatchAlertView is a custom controller I made to show alert messages.)

#pragma mark - CLLocation Manager 

-(void)startTrackingCurrentLocation:(BOOL)forTrip
{
    if (self.locationManager == nil)
    {
        self.locationManager = [[CLLocationManager alloc] init];
        self.locationManager.delegate = self;
        self.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
        self.locationManager.activityType = CLActivityTypeFitness;
        self.locationManager.distanceFilter = 5; //Require 15 meters of movement before we show an update
    }

    CLAuthorizationStatus status = [CLLocationManager authorizationStatus];
    if (status == kCLAuthorizationStatusAuthorizedAlways || status == kCLAuthorizationStatusAuthorizedWhenInUse)
    {
        NSLog(@"%@ Start tracking current location", self);

        self.trackingCurrentLocation = YES;
        self.gpsTrackingForTrip = forTrip;

        //We wait until we have a GPS point before we start showing it
        self.showCurrentLocation = NO;
        [self.locationManager startUpdatingLocation];
    }
    else
    {
        [self presentControllerWithName:@"GPWatchAlertView" context:@"Unauthorized GPS Access.  Please open Topo Maps+ on your iPhone and tap on current location."];
    }

}

-(void)stopTrackingCurrentLocation:(id)sender
{
    NSLog(@"%@ Stop tracking current location", self);

    self.trackingCurrentLocation = NO;
    [self.locationManager stopUpdatingLocation];
    self.showCurrentLocation = NO;
}

-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
    CLLocation* loc = [locations lastObject];

   ... 

}

回答2:

The answer by Stephan should work (haven't tested it), with just one exception. WatchKit requires "Always" permission for the location manages. This is because your phone is really running the watch extension, in background mode. So if you only ask for "When in Use" permission, you will never get locations returned to your watch extension.

Try changing the line:

if (status == kCLAuthorizationStatusAuthorizedAlways || status == kCLAuthorizationStatusAuthorizedWhenInUse)

with:

if (status == kCLAuthorizationStatusAuthorizedAlways)

回答3:

you should get user location on iphone app not in extension. Please check apple documentation.

来源：https://stackoverflow.com/questions/27960108/how-to-calculate-current-location-in-watchkit-extension

标签

ios

watchkit

apple-watch