Calculating Distance iOS MapKit Using CLLocation

问题

I am trying to find the distance in miles using the latitude and longitude. I have the following method:

- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation
{
    if(!newLocation) return; 

    if ((oldLocation.coordinate.latitude != newLocation.coordinate.latitude) &&
        (oldLocation.coordinate.longitude != newLocation.coordinate.longitude))
    {



        CLLocation *loc1 = [[CLLocation alloc] initWithLatitude:oldLocation.coordinate.latitude longitude:oldLocation.coordinate.longitude];
        CLLocation *loc2 = [[CLLocation alloc] initWithLatitude:newLocation.coordinate.latitude longitude:newLocation.coordinate.latitude];

        CLLocationDistance distance = ([loc2 distanceFromLocation:loc1]) * 0.000621371192;

        //distance = distance; 

        NSLog(@"Total Distance %f in miles",distance);
    }

}

For some reason it prints out something like 5678.32 miles. The location is pretty much stationary and not moving at all.

回答1:

CLLocation *loc2 = [[CLLocation alloc] initWithLatitude:newLocation.coordinate.(!!!!!)latitude longitude:newLocation.coordinate.(!!!!!)latitude];

回答2:

You are initializing loc2 with the latitude of the new location for both the longitude and the latitude:

This line:

CLLocation *loc2 = [[CLLocation alloc] initWithLatitude:newLocation.coordinate.latitude longitude:newLocation.coordinate.latitude];

Should say:

CLLocation *loc2 = [[CLLocation alloc] initWithLatitude:newLocation.coordinate.latitude longitude:newLocation.coordinate.longitude];

Hope it helps!

来源：https://stackoverflow.com/questions/6685553/calculating-distance-ios-mapkit-using-cllocation

标签

ios

mapkit