Question

我在xcode中有一个tabbar项目，在第一个视图中我需要找到我的GPS位置，我需要在appdelegate上保存两个变量的经度和纬度。这里有一些代码：

FirstViewController.h

#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>

@interface FirstViewController : UIViewController <CLLocationManagerDelegate>{ 
    CLLocationManager *locationManager;     
}    
@property (nonatomic, retain) CLLocationManager *locationManager;
@end

FirstViewController.m

#import "FirstViewController.h"
#import "CampeggiandoAppDelegate.h"
#import <CoreLocation/CoreLocation.h>

@interface FirstViewController ()

@end

@implementation FirstViewController
@synthesize locationManager;


- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {

        self.tabBarItem.image = [UIImage imageNamed:@"ic_home2"];
        self.tabBarItem.title=@"Home";
    }
    return self;
}
    - (void)viewDidLoad {

    [super viewDidLoad];
    self.locationManager = [[[CLLocationManager alloc] init] autorelease];
    self.locationManager.delegate = self;

    self.locationManager.distanceFilter=500.0f;
    self.locationManager.desiredAccuracy=kCLLocationAccuracyHundredMeters;
    [self.locationManager startUpdatingLocation];



}

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

    CampeggiandoAppDelegate *appDelegate=(CampeggiandoAppDelegate*)[[UIApplication sharedApplication]delegate];


    appDelegate.latitudineDel=[NSString stringWithFormat:@"%3.5f", newLocation.coordinate.latitude];
    appDelegate.longitudineDel=[NSString stringWithFormat:@"%3.5f", newLocation.coordinate.longitude];

}

当我运行编译器并且最合适的视图出现时，应用程序崩溃并出现此异常：

由于未捕获的异常而终止应用 'NSInvalidArgumentException'，原因：' - [AppDelegate setLatitudineDel：]：无法识别的选择器发送到实例0x84210b0'

有任何帮助吗？感谢。

Answer 1

在按照您的方式设置变量之前，您的类接口应该如下所示：

@interface CampeggiandoAppDelegate : UIResponder <UIApplicationDelegate> {
// ...
// some ivars
// ...
}

@property (nonatomic, strong) NSString *latitudineDel;
@property (nonatomic, strong) NSString *longitudineDel;

@end

你现在所拥有的是：

@interface CampeggiandoAppDelegate : UIResponder <UIApplicationDelegate> {
// ...
NSString *latitudineDel;
NSString *longitudineDel

// ...
}

@end

因此没有这些实例变量的setter，这就是抛出异常的原因。有关属性的更多信息，请阅读this。

CLLocation不起作用 - 无法识别的选择器发送到实例

1 个答案: