MKReverseGeocoder的问题

Question

由于某些原因，我无法从我的代码中获取城市(地区)的名称。请帮帮我！

 - (void)viewDidLoad {
        [super viewDidLoad];


        self.lm = [[CLLocationManager alloc] init];
        lm.delegate = self;
        lm.desiredAccuracy = kCLLocationAccuracyBest;
        lm.distanceFilter = kCLDistanceFilterNone;
        [lm startUpdatingLocation];

    }


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

        if (!geocoder) {
            geocoder = [[MKReverseGeocoder alloc] initWithCoordinate:newLocation.coordinate];
            geocoder.delegate = self;
            [geocoder start];
        }

        NSString *lat = [[NSString alloc] initWithFormat:@"%f", newLocation.coordinate.latitude];
        NSString *lng = [[NSString alloc] initWithFormat:@"%f", newLocation.coordinate.longitude];
        NSString *acc = [[NSString alloc] initWithFormat:@"%f", newLocation.horizontalAccuracy];

        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:lat message:lng  delegate:self cancelButtonTitle:acc otherButtonTitles: @"button", nil];
        [alert show];
        [alert release];

        [lat, lng, acc release];


    }

    - (void) reverseGeocoder:(MKReverseGeocoder *)geo didFailWithError:(NSError *)error {
            [geocoder release];
            geocoder = nil;

        }



        - (void)reverseGeocoder:(MKReverseGeocoder *)geo didFindPlacemark:(MKPlacemark *)placemark {

             **THIS IS WHERE THE ERROR IS OCCURRING** (REQUEST FOR MEMBER 'LOCALITY' IN SOMETHING NOT A STRUCTURE OR UNION)

            location = [NSString stringWithFormat:@"%@", placemark.locality]; 
            [geocoder release];
            geocoder = nil;
        }

Answer 1

我知道这是一个相对陈旧的问题，但是...

我遇到了完全相同的问题，并求助于使用addressDictionary placemark属性，例如，

[placemark.addressDictionary objectForKey@"City"]

而不是

placemark.subAdministrativeArea

我不明白为什么后者也不能工作。

Answer 2

当您试图访问结构的成员，但访问的对象不是结构时，通常会出现此错误。例如：

struct {
    int a;
    int b;
} foo;
int fum;
fum.d = 5;

如果你试图在有指针的情况下访问一个实例，也会发生这种情况，反之亦然。例如：

struct foo {
    int x, y, z;
};

struct foo a, *b = &a;
b.x = 12;  /* This will generate the error, it should be b->x or (*b).x */

如果执行以下操作，它也会出现：

struct foo {   int x, int y, int z }foo; 
foo.x=12

而不是：

struct foo {   int x; int y; int z; }foo; 
foo.x=12

因为这样，你就会得到一个看起来像是在处理实例的代码，而实际上它是在处理指针。

在我看来，你需要检查一下你的代码。也许，试试这个：

NSString *strLocation = (NSString *)placemark.locality; // Get locality