Question

出于某种原因，我无法从我的代码中获取城市名称（地区）。请帮忙！

 - (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

我意识到这是一个相对古老的问题，但是......

我遇到了完全相同的问题并使用了addressDictionary地标属性，例如，

[placemark.addressDictionary objectForKey@"City"]

而不是

placemark.subAdministrativeArea

我不明白为什么后者也不起作用。

Answer 2

当您尝试访问结构的成员但在非结构的某些内容时，通常会发生此错误。例如：

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

如果您在有指针时尝试访问实例，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 */

如果你这样做也会出现：

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

因为那样，你得到的代码看起来像处理实例，实际上它正在处理指针。

在我看来，您需要检查您的代码。或许，试试这个：

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

MKReverseGeocoder的问题

2 个答案: