Question

我刚刚开始使用Objective C进行编码，并且正在创建一个应用程序来跟踪用户位置，并发送一个包含latlng的警报。这段代码没有丝毫完整，但我遇到了一个问题，试图使用我在“viewDidLoad”中创建的“lat”变量作为警报。我在CLLocationManager委托/方法中声明了变量（我真的不知道它叫什么），我不知道如何在其他地方使用它。

    - (void)viewDidLoad
{
    locationManager =[[CLLocationManager alloc] init];

locationManager.delegate = self; 
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.distanceFilter = 100.0f;
[locationManager startUpdatingLocation];


UIAlertView *message = [[UIAlertView alloc] initWithTitle: @"Your current Latitude is:"
                                                  message:This is where I want to put the variable "lat"
                                                 delegate:nil
                                        cancelButtonTitle:@"OK"
                                        otherButtonTitles:nil];   
[message show];    

[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.

}

-(void) locationmanager: (CLLocationManager *) manager
        didUpdateToLocation: (CLLocation *) newLocation
        fromLocation: (CLLocation *) oldLocation
{ 
    NSString *lat = [[NSString alloc] initWithFormat: @"%g",newLocation.coordinate.latitude];
    NSString *lng = [[NSString alloc] initWithFormat:@"%g", newLocation.coordinate.longitude];  
}

任何帮助将不胜感激！

Answer 1

简单的解决方案。你的ViewController .h看起来应该是这样的

@interface ViewController : UIViewController {
    NSString *lat;
    NSString *lng;
}

然后这就变成了

-(void) locationmanager: (CLLocationManager *) manager
    didUpdateToLocation: (CLLocation *) newLocation
    fromLocation: (CLLocation *) oldLocation
{ 
    lat = [[NSString alloc] initWithFormat: @"%g",newLocation.coordinate.latitude];
    lng = [[NSString alloc] initWithFormat:@"%g", newLocation.coordinate.longitude];  
    NSLog(lat);
    NSLog(lng);
}

NSlog simple out将放置在位于您编码的下方的控制台

除去

UIAlertView *message = [[UIAlertView alloc] initWithTitle: @"Your current Latitude is:"
                                              message:This is where I want to put the variable "lat"
                                             delegate:nil
                                    cancelButtonTitle:@"OK"
                                    otherButtonTitles:nil];   
[message show];

因为只要加载视图就会显示警告

希望这有帮助

使用在不同方法中的其他地方声明的变量

1 个答案: