iphone - 从其他 ViewController 的 locationManager 方法访问 newLocation

Question

我正在使用 CoreLocation 并从我的应用程序 AppDelegate 中启动 locationManager。下面的示例代码...

AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // ...

    // start location manager
    if([CLLocationManager locationServicesEnabled])
    {
        myLocationManager_ = [[CLLocationManager alloc] init];
        myLocationManager_.delegate = self;
        [myLocationManager_ startUpdatingLocation];
    }
    else 
    {
        // ... rest of code snipped to keep this short

在这个方法中我们可以看到更新后的位置。

-(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    NSString *currentLatitude = [[NSString alloc] initWithFormat:@"%g", newLocation.coordinate.latitude];
    NSLog(@"AppDelegate says: latitude: %@", currentLatitude);

    // ... rest of code snipped

现在，在我的应用程序的其他区域中，我需要确定用户当前位置(纬度、经度)。我可以将上面的代码合并到需要当前位置的 ViewController 中，但随后我会运行多个 CLLocationManager 实例(我认为) - 为什么要重复此代码？有没有一种方法可以让我从其他 ViewController 中获取 AppDelegate 的位置信息？

PS - 我正在使用带有 ARC 的 Xcode 4.3

Answer 1

谢谢莫哈比塔为我回答这个问题!为了清楚起见，我发布了我的代码供其他人欣赏。

注意:下面仅显示相关部分。

AppDelegate.h

@interface AppDelegate : UIResponder <UIApplicationDelegate, CLLocationManagerDelegate>

@property (strong, nonatomic) UIWindow *window;

@property (nonatomic, strong) CLLocationManager *myLocationManager;
@property (nonatomic, strong) CLLocation *currentLocation;

AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

    if([CLLocationManager locationServicesEnabled])
    {
        currentLocation_ = [[CLLocation alloc] init];

        myLocationManager_ = [[CLLocationManager alloc] init];
        myLocationManager_.delegate = self;
        [myLocationManager_ startUpdatingLocation];
    }
}

-(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    currentLocation_ = newLocation;
}

其他ViewControllers.h

@property (strong, nonatomic) CLLocation *currentLocation;

其他ViewController.m

- (void)viewDidLoad
{
    [super viewDidLoad];

    if([CLLocationManager locationServicesEnabled])
    {
        AppDelegate *appDelegate = (AppDelegate *) [[UIApplication sharedApplication] delegate];
        currentLocation_ = [[CLLocation alloc] initWithLatitude:appDelegate.currentLocation.coordinate.latitude longitude:appDelegate.currentLocation.coordinate.longitude];
    }
}

再次感谢!