iOS CLLocationManager 在一个单独的类中

Question

我有多个 View Controller 需要获取用户的位置，所以我想创建一个单独的类，ViewController 可以调用它来获取用户的最新位置。

locationManager:didUpdateToLocation:fromLocation 返回无效。如何在计算出用户的纬度和经度后立即将纬度和经度数据传回我的 ViewController？

我可以尝试在我的 locationManaging 类中编写 getter 和 setter，但如果这样做，我如何知道何时从我的 ViewController 类中调用纬度 getter 和经度 getter 方法？如何让 ViewController 的主线程等待来自 locationManaging 类的纬度和经度值？

谢谢!

Answer 1

正如 user1071136 所说，单例位置管理器可能就是您想要的。创建一个类，它是 NSObject 的一个子类，只有一个属性，一个 CLLocationManager。

LocationManagerSingleton.h:

#import <MapKit/MapKit.h>

@interface LocationManagerSingleton : NSObject <CLLocationManagerDelegate>

@property (nonatomic, strong) CLLocationManager* locationManager;

+ (LocationManagerSingleton*)sharedSingleton;

@end

LocationManagerSingleton.m:

#import "LocationManagerSingleton.h"

@implementation LocationManagerSingleton

@synthesize locationManager;

- (id)init {
    self = [super init];

    if(self) {
        self.locationManager = [CLLocationManager new];
        [self.locationManager setDelegate:self];
        [self.locationManager setDistanceFilter:kCLDistanceFilterNone];
        [self.locationManager setHeadingFilter:kCLHeadingFilterNone];
        [self.locationManager startUpdatingLocation];
        //do any more customization to your location manager
    }

    return self;
}    

+ (LocationManagerSingleton*)sharedSingleton {
    static LocationManagerSingleton* sharedSingleton;
    if(!sharedSingleton) {
        static dispatch_once_t onceToken;
        dispatch_once(&onceToken, ^{
            sharedSingleton = [LocationManagerSingleton new];
        }
    }

    return sharedSingleton;
}

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
    //handle your location updates here
}

- (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading {
    //handle your heading updates here- I would suggest only handling the nth update, because they
    //come in fast and furious and it takes a lot of processing power to handle all of them
}

@end

要获取最近收到的位置，只需使用 [LocationManagerSingleton sharedSingleton].locationManager.location。预热 GPS 以获得准确位置可能需要几秒钟。