CLLocation調用委托方法

Question

我試圖在切換到特定視圖控制器（FeedVC）時獲取用戶位置，這是我當前擁有的代碼：

FeedVC.h

#import <CoreLocation/CoreLocation.h>
@interface FeedVC : UIViewController <CLLocationManagerDelegate>

FeedVC.m

@implementation FeedVC
{
    CLLocationManager *locationManager;
    CLLocation *location;
}

- (void)viewDidLoad {
    [super viewDidLoad];

    if (!locationManager)
        locationManager = [[CLLocationManager alloc] init];

    locationManager.delegate = self;
    locationManager.distanceFilter = kCLDistanceFilterNone;
    locationManager.desiredAccuracy = kCLLocationAccuracyKilometer;

    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
        [locationManager requestWhenInUseAuthorization];

    [locationManager startUpdatingLocation];
}

-(void) locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
    NSLog(@"did update locations");

    location = [locations lastObject];
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
    NSLog(@"didFailWithError: %@", error);
}

-(void) viewWillAppear:(BOOL)animated
{
    NSLog(@"%.2f", location.coordinate.latitude);
}

方法locationManager: didUpdateLocations:沒有被調用（因為未顯示NSLog）我已經在這里關注所有文檔和其他答案，但是我找不到問題的根源，謝謝！

Answer 1

不要調用[locationManager startUpdatingLocation]; 在viewDidLoad中，在委托方法中調用它：

-(void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status{
    if (status == kCLAuthorizationStatusAuthorizedWhenInUse) {
        [locationManager startUpdatingLocation];
    }
}

如果尚未在plist中添加NSLocationWhenInUseUsageDescription，請添加它以描述為什么要使用位置服務