Trying to Center Map on Pin (MKMapView)

Question

Struggling to find a way to make map zoom and center on annotation pin. Pin drops, but map loads ocean. Code is below.

- (void) connectionDidFinishLoading:(NSURLConnection *)connection
{
  [self setString];

  NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:responseData options:0 error:nil];
  NSDictionary *location = [dic objectForKey:@"location"];
  NSDictionary *coordinate = [location objectForKey:@"coordinate"];
  NSString *lat = [coordinate objectForKey:@"latitude"];
  NSString *lon = [coordinate objectForKey:@"longitude"];

  for (NSDictionary *diction in coordinate)
  {
    [array addObject:lat];
    [array addObject:lon];
  }
  {
    CLLocationCoordinate2D track;
    track.latitude = [lat doubleValue];
    track.longitude = [lon doubleValue];

    MapViewAnnotation *newAnnotation = [[MapViewAnnotation alloc] initWithTitle:@"Title of Place Here" andCoordinate:track];

    [self.mapView addAnnotation:newAnnotation];
  }
}

2ND QUESTION, VERY RELATED:

After implementing the answer to the above question, I have since modified my code. Now, I have my coordinates coming to my MKMapView from the previous view, so that I don't have to bother making an API call twice, the second being IN the MKMapView. Currently in my ViewWillAppear I have the following, and AGAIN am experiencing a problem where the view will not center and zoom on the pin:

if ([self.stringToDisplay isEqualToString: @"Firehouse Gallery"])
{
    UIImage *img = [UIImage imageNamed:@"firehouse.jpg"];
    [imageView setImage:img];

    CLLocationCoordinate2D track;
    track.latitude = [lat doubleValue];
    track.longitude = [lon doubleValue];

    MKCoordinateRegion region;
    MKCoordinateSpan span;
    span.latitudeDelta = 0.01;
    span.longitudeDelta = 0.01;
    region.span = span;
    region.center = track;

    MapViewAnnotation *newAnnotation = [[MapViewAnnotation alloc] initWithTitle:@"Firehouse Gallery" andCoordinate:track];

    [self.mapView addAnnotation:newAnnotation];
    [self.mapView setRegion:region animated:TRUE];
    [self.mapView regionThatFits:region];
}

Feedback is DEEPLY appreciated, as I can't tell what else I should do. The pin loads on the correct coordinates, just doesn't center/zoom...

Solution 1

Try this:

{
    CLLocationCoordinate2D track;
    track.latitude = [lat doubleValue];
    track.longitude = [lon doubleValue];

    MKCoordinateRegion region;
    MKCoordinateSpan span;
    span.latitudeDelta = 0.01;
    span.longitudeDelta = 0.01;
    region.span = span;
    region.center = track;

    MapViewAnnotation *newAnnotation = [[MapViewAnnotation alloc] initWithTitle:@"Title of Place Here" andCoordinate:track];

    [self.mapView addAnnotation:newAnnotation];
    [self.mapView setRegion:region animated:TRUE];
    [self.mapView regionThatFits:region];
}

Solution 2

 - (void)zoomMapViewToFitAnnotationsWithExtraZoomToAdjust:(double)extraZoom
 {
    if ([self.annotations count] == 0) return;

    int i = 0;
    MKMapPoint points[[self.annotations count]];

    for (id<MKAnnotation> annotation in [self annotations])
    {
        points[i++] = MKMapPointForCoordinate(annotation.coordinate);
    }

    MKPolygon *poly = [MKPolygon polygonWithPoints:points count:i];

    MKCoordinateRegion r = MKCoordinateRegionForMapRect([poly boundingMapRect]);
    r.span.latitudeDelta += extraZoom;
    r.span.longitudeDelta += extraZoom;

    [self setRegion: r animated:YES];
 }

Comments

[Marc Etcheverry]

[self.mapView regionThatFits:region] Does nothing, it just creates a new region.