CLLocationDistance: Cant get "getDistanceFrom" to work.

Question

view based app,

.m
- (void)viewDidLoad {
    [super viewDidLoad];
    self.locationManager = [[[CLLocationManager alloc] init] autorelease];
    self.locationManager.delegate = self;
    [[self locationManager] startUpdatingLocation];

}


- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation {

    CurrentLocation = newLocation;
    [locationManager stopUpdatingLocation];
    myActivity.hidden=YES;
    [self reStart];
}


-(void)reStart{

        [self checkAndCreateDatabase];  //Sucess
    [self readFromDatabase]; //Success if I comment the get distance part
    [self sort]; //Success
}


-(void) readFromDatabase {
...

    CLLocationCoordinate2D cord;
    cord.latitude = [[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)] doubleValue];
    cord.longitude =[[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 3)] doubleValue];
    NSDate *today = [NSDate date];
    CLLocation *objectLocation = [[CLLocation alloc] initWithCoordinate:cord altitude:1 horizontalAccuracy:1 verticalAccuracy:-1 timestamp:today];
    CLLocationDistance distance = [objectLocation getDistanceFrom:CurrentLocation]/1000;
    NSLog([NSString stringWithFormat:@"%.0f", distance]);
}

What is wrong?

debugger says:

obj_msgSend
0x912e8688  <+0024>  mov    0x20(%edx),%edi

object from database: long: 59.291114 lat: 17.816191

Answer 1

Is CurrentLocation an instance-variable/property? You are setting it directly without an accessor and you are not retaining it. If it is released before you use it in getDistance: it will cause a crash.

If it is a property use the self.CurrentLocation to ensure it is retained.

Also, the construction...

NSLog([NSString stringWithFormat:@"%.0f", distance]);

... is risky and redundant. Use...

NSLog(@"%.0f", distance);

... instead.

Answer 2

Use distanceFromLocation: instead