Search code examples
core-locationcllocationmkmapview

Need distance from stored coordinates to current location


I am trying to get a distance from my longitude and latitude i have stored into core data, to the current location. I have this code, but i cannot figure out how to integrate the code for using the coordinates i have stored in core data. How do i use my coordinates stored in core data to get distance from user location? Thank you for any help!

CLLocation *to = [[CLLocation alloc]
                  initWithLatitude:mapView.userLocation.coordinate.latitude
                  longitude:mapView.userLocation.coordinate.longitude];

CLLocation *from = [[CLLocation alloc]
                    initWithLatitude:mapView.userLocation.coordinate.latitude
                    longitude:mapView.userLocation.coordinate.longitude];

CLLocationDistance distance = [to distanceFromLocation:from];

_distance.text = [[NSString alloc]initWithFormat:@"%g",distance];

I get my core data coordinates like this:

_buyLong.text = [[_itemDetailArray valueForKey:@"longitude"] description];
_buyLatitude.text = [[_itemDetailArray valueForKey:@"latitude"] description];

Solution

  • Figured it out so hopefully someone can benefit:

    NSString *savedLatitude = [[_itemDetailArray valueForKey:@"latitude"] description];
        double latDouble = [savedLatitude doubleValue];
    
    NSString *savedLongitude = [[_itemDetailArray valueForKey:@"longitude"] description];
        double longDouble = [savedLongitude doubleValue];
    
    NSLog(@"Value Lat: %f", latDouble);
    NSLog(@"Value Long: %f", longDouble);
    
    // Item Location from Array
    itemCoordinate.latitude = latDouble;
    itemCoordinate.longitude = longDouble;
    
    // User Location from Device
    [currentLocation stopUpdatingLocation];
    theCoordinate.latitude = newLocation.coordinate.latitude;
    theCoordinate.longitude = newLocation.coordinate.longitude;
    
    CLLocation *loc = [[CLLocation alloc] initWithLatitude:theCoordinate.latitude longitude:theCoordinate.longitude];
    CLLocation *loc2 = [[CLLocation alloc] initWithLatitude:itemCoordinate.latitude longitude:itemCoordinate.longitude];
    
    CLLocationDistance dist = [loc distanceFromLocation:loc2] *0.0006213; // Convert Meters to Miles
    NSString *distance = [NSString stringWithFormat:@"%.1f",dist];
    
    NSLog(@"DIST in Miles: %f", dist); // Wrong formatting may show wrong value!}
    
    _distance.text = distance;