ios - locationManager避免Label中的(空)字符串

Question

我有一些代码可以找到用户位置并将其返回到Label中。在某些情况下，subAdministrativeArea不可用或通途，我想修改我的字符串，使其不显示(空)。我尝试了一些是否检查这一点，但如果(null)大于一个，则存在问题。有人对此有想法吗？

这是我当前的代码，需要对其进行修改以检测地标对象是否等于null:

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
        CLLocation *currentLocation = newLocation;
        [location stopUpdatingLocation];

        [geocoder reverseGeocodeLocation:currentLocation completionHandler:^(NSArray *placemarks, NSError *error) {
        if (error == nil && [placemarks count] > 0) {
            placemark = [placemarks lastObject];

            countryDetected = placemark.ISOcountryCode;
            placeLabel.text = [NSString stringWithFormat:@"%@, %@, %@, %@, %@ %@", placemark.country, placemark.subAdministrativeArea, placemark.subLocality, placemark.postalCode, placemark.thoroughfare, placemark.subThoroughfare];
            userPlace = [NSString stringWithFormat:@"%@, %@, %@, %@, %@ %@", placemark.country, placemark.subAdministrativeArea, placemark.subLocality, placemark.postalCode, placemark.thoroughfare, placemark.subThoroughfare];

        } else {
            NSLog(@"%@", error.debugDescription);
        }
    } ];
}

Answer 1

试试这个..如果placemark.subAdministrativeArea是nil，那么您可以编写自己的字符串，如果条件另有设置，则将placemark.subAdministrativeArea的值设置为字符串变量，然后将其分配给UILable ...

更新:

NSMutableString *strLblTexts = [[NSMutableString alloc] init];
if (placemark.country != nil) {
        [strLblTexts appendString:placemark.country];
}
if (placemark.subAdministrativeArea != nil) {
        if ([strLblTexts isEqualToString:@""]||[strLblTexts isEqual:nil]) {
        [strLblTexts appendString:placemark.subAdministrativeArea];
    }
    else{
        NSString *strtemp=[NSString stringWithFormat:@",%@",placemark.subAdministrativeArea];

        NSLog(@">>>>>>>>>>>>> str temp :%@", strtemp);
        [strLblTexts appendString:strtemp];
    }
}
if (placemark.subLocality != nil) {
        if ([strLblTexts isEqualToString:@""]||[strLblTexts isEqual:nil]) {
        [strLblTexts appendString:placemark.subLocality];
    }
    else{
        NSString *strtemp=[NSString stringWithFormat:@",%@",placemark.subLocality];

        NSLog(@">>>>>>>>>>>>> str temp :%@", strtemp);
        [strLblTexts appendString:strtemp];
    }
}

像其他3个字段一样进行操作，最后像波纹管一样将该值设置为 UILable ...

placeLabel.text = strLblTexts;