How to find Latitude and Longitude from Address in iPhone

Question

I am making one application in which i am getting the address, i need to find the latitude and longitude from that address and show the place in map

- (void)viewDidLoad 
{
    [super viewDidLoad];

    [mapView setMapType:MKMapTypeStandard];
    [mapView setZoomEnabled:YES];
    [mapView setScrollEnabled:YES];
    mapView.showsUserLocation = YES;
    MKCoordinateRegion region = { {0.0, 0.0 }, { 0.0, 0.0 } }; 

    geoCoder.delegate = self;
    [geoCoder start];

    double latitude = 0, longitude = 0;

    region.center.latitude = latitude;   
    region.center.longitude = longitude;  
    region.span.longitudeDelta = 0.01f;
    region.span.latitudeDelta = 0.01f;
    [mapView setRegion:region animated:YES]; 

    [mapView setDelegate:self];

    DisplayMap *ann = [[DisplayMap alloc] init]; 
    ann.title = @"BarRestaurant";
    ann.subtitle = @"..."; 
    ann.coordinate = region.center; 
    [mapView addAnnotation:ann];
}

-(MKAnnotationView *)mapView:(MKMapView *)mV viewForAnnotation:
(id <MKAnnotation>)annotation {

    MKPinAnnotationView *pinView = nil; 
    if(annotation != mapView.userLocation) 
    {
        static NSString *defaultPinID = @"com.invasivecode.pin";
        pinView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:defaultPinID];
        if ( pinView == nil ) pinView = [[[MKPinAnnotationView alloc]
                                          initWithAnnotation:annotation reuseIdentifier:defaultPinID] autorelease];

        pinView.pinColor = MKPinAnnotationColorRed; 
        pinView.canShowCallout = YES;
        pinView.animatesDrop = YES;
    } 
    else 
    {
        [mapView.userLocation setTitle:@"I am here"];
    }
    return pinView;
}

- (CLLocationCoordinate2D) geoCodeUsingAddress:(NSString *)address
{
    appRestaurantAppDelegate *delegate = [[UIApplication sharedApplication] delegate];

    double latitude = 0, longitude = 0;

    address = delegate.streetName;

    NSString *esc_addr =  [address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

    NSString *req = [NSString stringWithFormat:@"http://maps.google.com/maps/api/geocode/json?sensor=false&address=%@", esc_addr];

    NSString *result = [NSString stringWithContentsOfURL:[NSURL URLWithString:req] encoding:NSUTF8StringEncoding error:NULL];
    if (result) 
    {
        NSScanner *scanner = [NSScanner scannerWithString:result];
        if ([scanner scanUpToString:@"\"lat\":" intoString:nil] && [scanner scanString:@"\"lat\":" intoString:nil]) {
            [scanner scanDouble:&latitude];
            if ([scanner scanUpToString:@"\"lng\":" intoString:nil] && [scanner scanString:@"\"lng\":" intoString:nil]) 
            {
                [scanner scanDouble:&longitude];
            }
        }
    }
    CLLocationCoordinate2D center;
    center.latitude = latitude;
    center.longitude = longitude;
    return center;
}

however i am unable to find the latitude and longitude please help me where i am doing wrong in the delegate i am getting the address from web server

Answer 1

Try this code,

- (CLLocationCoordinate2D) geoCodeUsingAddress:(NSString *)address
{
    double latitude = 0, longitude = 0;
    NSString *esc_addr =  [address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    NSString *req = [NSString stringWithFormat:@"http://maps.google.com/maps/api/geocode/json?sensor=false&address=%@", esc_addr];
    NSString *result = [NSString stringWithContentsOfURL:[NSURL URLWithString:req] encoding:NSUTF8StringEncoding error:NULL];
    if (result) {
        NSScanner *scanner = [NSScanner scannerWithString:result];
        if ([scanner scanUpToString:@"\"lat\":" intoString:nil] && [scanner scanString:@"\"lat\":" intoString:nil]) {
            [scanner scanDouble:&latitude];
            if ([scanner scanUpToString:@"\"lng\":" intoString:nil] && [scanner scanString:@"\"lng\":" intoString:nil]) {
                [scanner scanDouble:&longitude];
            }
        }
    }
    CLLocationCoordinate2D center;
    center.latitude = latitude;
    center.longitude = longitude;
    return center;
}

Also refer this link

Answer 2

After ios 5.0, google maps and google maps api should not be used in native mapview. It will violate both google and apple policies.

But we can find the location from apple provided mapkit framework itself.

Please see the below link. https://developer.apple.com/library/ios/documentation/userexperience/conceptual/LocationAwarenessPG/UsingGeocoders/UsingGeocoders.html

Its very simple using " CLGeocoder " like:

geocoder = [[CLGeocoder alloc] init];    

[geocoder geocodeAddressString:@"1 Infinite Loop"
 completionHandler:^(NSArray* placemarks, NSError* error){
     for (CLPlacemark* aPlacemark in placemarks)
     {
         // Process the placemark.
     }
}];