ios - 获取用户的当前位置 iOS 8.0

Question

我尝试使用 MapKit 和 CoreLocation 获取用户当前位置。我真的是 Objective-C 的新手。至于我的研究，从旧版 iOS 到 iOS 8.0 的实现略有不同。我已经正确地遵循了一切。它仍然在获取当前位置。我的实际目标是当用户在文本字段中提供位置时，在运行时在 mapKit 上获取固定用户位置。

filename.h
#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>
@interface LocationSelectionViewController : UIViewController <CLLocationManagerDelegate>
@property (weak, nonatomic) IBOutlet UITextField *insertLocation;
@property (strong, nonatomic) IBOutlet MKMapView *serviceLocation;
- (IBAction)next:(id)sender;

@end

#import "LocationSelectionViewController.h"
#import <CoreLocation/CoreLocation.h>

@interface LocationSelectionViewController () <CLLocationManagerDelegate>

@end

@implementation LocationSelectionViewController
CLLocationManager *locationManager;
@synthesize serviceLocation;

- (void)viewDidLoad {
    [super viewDidLoad];
    locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self;
    [locationManager requestAlwaysAuthorization];
    [locationManager startUpdatingLocation];
    // Do any additional setup after loading the view.
    self.serviceLocation = [[MKMapView alloc] initWithFrame:self.view.bounds];
    self.serviceLocation.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    [self.view addSubview:self.serviceLocation];
    [self.serviceLocation.delegate self];
    //[self.serviceLocation setShowsUserLocation:YES];
}

/*- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation{
    CLLocationCoordinate2D loc=[userLocation coordinate];
    MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(loc, 100, 100);
    [self.serviceLocation setRegion:region animated:YES];
}*/

-(void) locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray<CLLocation *> *)locations{
    [locationManager requestAlwaysAuthorization];
    [locationManager startUpdatingLocation];

}
-(void) locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status{
    if(status == kCLAuthorizationStatusAuthorizedAlways || status == kCLAuthorizationStatusAuthorizedWhenInUse){
        self.serviceLocation.showsUserLocation = YES;
    }
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

- (IBAction)next:(id)sender {
}
@end

如图所示，我已根据 iOS 8 要求添加了两个属性。

谁能建议我存档:

• 获取用户当前位置。
• 在运行时从文本字段获取位置并固定在 MapKip 上。

Answer 1

您请求和启动位置更新的流程不正确。首先，requestAlwaysAuthorization 不会立即更改授权状态，因为它需要用户在警报中按下 Allow 或 Don't Allow 按钮。所以你应该在得到结果后才开始位置更新。然后在didUpdateLocations 不需要重新请求/开始。

按照下面的方式做，

Dn 你的 viewDidLoad

 BOOL isAuthorized = [CLLocationManager authorizationStatus] == kCLAuthorizationStatusAuthorizedAlways;
 if (isAuthorized) {
     [locationManager startUpdatingLocation];
 }
 else {
     [locationManager requestAlwaysAuthorization];
 }

然后像这样实现委托(delegate)方法

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray<CLLocation *> *)locations {
   CLLocation *current = locations.firstObject;
}

- (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status{
    if(status == kCLAuthorizationStatusAuthorizedAlways || status == kCLAuthorizationStatusAuthorizedWhenInUse){
        self.serviceLocation.showsUserLocation = YES;
       [locationManager startUpdatingLocation];
    }
}

在 iOS 8 中，为了请求权限，您应该在 info.plist 中添加用法描述字符串。在您的情况下，关键是 NSLocationAlwaysUsageDescription。