Question

如何将纬度和经度坐标保存到nsstring，以便我可以在另一个函数中使用它。基本上，我只想显示从坐标中检索到的值，以传递给uilabel。

- (void)viewDidLoad
{
[super viewDidLoad];
[self getCurrentLocation];
NSLog(@"lat is %@ : lon is %@",self.latPoint, self.longPoint);

}

我试图用NSlog检索上面的内容并显示为null。我在我的.h文件中创建了两个NSString属性作为latPoint / longPoint

- (void)getCurrentLocation {
if ([CLLocationManager locationServicesEnabled]) {
    self.locationManager = [[CLLocationManager alloc] init];
    self.locationManager.delegate = self;
    [self.locationManager startUpdatingLocation];
} else {
    NSLog(@"Location services are not enabled");
}

}



- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
CLLocation *location = [locations lastObject];
self.latPoint = [NSString stringWithFormat:@"%f", location.coordinate.latitude];
self.lonPoint = [NSString stringWithFormat:@"%f", location.coordinate.longitude];
}

Answer 1

您看到的行为很可能是因为CLLocationManager回调是异步的。您的NSLog调用打印self.latPoint和self.longPoint（最有可能）在位置管理员有时间查找并存储当前位置之前发生。

如果您将NSLog(@"lat is %@ : lon is %@",self.latPoint, self.longPoint);语句移至didUpdateLocations方法，则只要位置管理员找到（并更新）您当前的位置，您就会看到它被调用。

您只需要对CLLocationManager回调做出反应，而不是尝试确定何时找到该位置。

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
    CLLocation *location = [locations lastObject];
    self.latPoint = [NSString stringWithFormat:@"%f", location.coordinate.latitude];
    self.lonPoint = [NSString stringWithFormat:@"%f", location.coordinate.longitude];

    NSLog(@"lat is %@ : lon is %@",self.latPoint, self.longPoint);
    //Now you know the location has been found, do other things, call others methods here
}

约翰

iOS将纬度/经度坐标保存到NSString以输出到标签

1 个答案: