why does it not zoom? - ios

Question

new to objective c!
Im trying to make my mapview zoom. I've copied some code from a assignment in my book, but it somehow doesn't zoom. Just shows the unzoomed mapview.
Any suggestions? See The viewController code below.
Also - a few words on the difference of importing a header file and the #class directive would be great!?
Thanks in advance
#import "TrackViewController.h"
#import "MainWindowViewController.h"
#import <MapKit/MapKit.h>
#class MainWindowViewController;
#implementation TrackViewController
- (id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self=[super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if(self)
{
locationManager = [[CLLocationManager alloc]init];
[locationManager setDelegate:self];
[locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
}
return self;
}
-(IBAction) back:(id)sender
{
[self dismissViewControllerAnimated:YES completion:nil];
}
-(void) findLocation;
{
[locationManager startUpdatingLocation];
}
-(void) foundLocation:(CLLocation *)loc
{
CLLocationCoordinate2D coord = [loc coordinate];
MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(coord, 100, 100);
[worldView setRegion:region];
[locationManager stopUpdatingLocation];
}
-(void)viewDidLoad
{
[worldView setShowsUserLocation:YES];
[worldView setMapType:MKMapTypeHybrid];
}
-(void)dealloc
{
[locationManager setDelegate:nil];
}
- (void) locationManager:(CLLocationManager *) manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
NSTimeInterval t = [[newLocation timestamp] timeIntervalSinceNow];
if(t<180){
return;
}
[self foundLocation:newLocation];
}
-(void)locationManager:(CLLocationManager *)manager
didFailWithError:(NSError *)error
{
NSLog(#"Could not find location: %#", error);
}
#end

Answer 1

The only thing I notice is to change your setRegion line to:
[worldView setRegion:region animated:YES];//instead of just setRegion
-The setRegion: documentation states:
The area currently displayed by the map view
-While the setRegion:animated: documentation states:
Changes the currently visible region and optionally animates the change
Otherwise, I recommend printing out your CLLocationCoordinate2D object and ensuring it is valid.