GeoDemo-ios2

ViewController.m fetchedData

- (void)fetchedData:(NSData *)responseData {
    NSError* error;
    //Build a JSON object from the response Data
    NSArray* json = [NSJSONSerialization
                     JSONObjectWithData:responseData //1
                     
                     options:kNilOptions
                     error:&error];
    
    //Go through each POI in the JSON data and pull out the important fields
    for (NSDictionary *pointOfInterest in json) {
        NSLog(@"POI:%@", pointOfInterest);
        
        
        CLLocationCoordinate2D mapPoint = mapView.centerCoordinate;
        NSString *latString = [pointOfInterest valueForKey:@"Latitude"];
        NSString *longString = [pointOfInterest valueForKey:@"Longitude"];
        NSString *description = [pointOfInterest valueForKey:@"Description"];
        NSString *url = [pointOfInterest valueForKey:@"Url"];
        mapPoint.latitude = [latString doubleValue];
        mapPoint.longitude = [longString doubleValue];
        
        //Add a new map annotation for each POI
        MKPointAnnotation *anny = [[MKPointAnnotation alloc] init];
        anny.coordinate = mapPoint;
        anny.title = description;
        anny.subtitle = url;
        [mapView addAnnotation:anny];
    }
}

ViewController.m getCurrentPointsOfInterest

- (void)getCurrentPointsOfInterest {
    NSURL *requestUrl = [NSURL URLWithString:[NSString stringWithFormat:@"%@?latitude=%f&longitude=%f&radiusInMeters=1000",kGetPOIUrl, [currentLocation coordinate].latitude, [currentLocation coordinate].longitude]];
    //Get our POI
    dispatch_async(kBgQueue, ^{
        NSData* data = [NSData dataWithContentsOfURL:
                        requestUrl];
        [self performSelectorOnMainThread:@selector(fetchedData:)
                               withObject:data waitUntilDone:YES];
    });
}

ViewController.m misc

- (IBAction)tapRefresh:(id)sender {
    [self getCurrentPointsOfInterest];
}

- (void)locationError:(NSError *)error {
    labelLatitude.text = [error description];
    labelLongitude.text = nil;
}

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [self getCurrentPointsOfInterest];
}

ViewController.m viewForAnnotation

- (MKAnnotationView *)mapView:(MKMapView *)map viewForAnnotation:(id <MKAnnotation>)annotation
{
    
    if ([annotation isKindOfClass:[MKUserLocation class]])
    {
        return nil;
    }
    
    static NSString *AnnotationViewID = @"annotationViewID";
    
    MKPinAnnotationView *annotationView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:AnnotationViewID];
    
    if (annotationView == nil)
    {
        annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:AnnotationViewID];
    }
    annotationView.canShowCallout = YES;
    annotationView.annotation = annotation;
    
    return annotationView;
}