MapView 不会加载当前用户位置，也不会居中/缩放它

Question

我正在尝试在MapView上显示我当前的位置。我在情节提要中添加了一个按钮。

第一个问题：当前位置未显示在我的屏幕上。

第二个问题：如果我单击按钮，MapView 不会缩放到位置。

My ViewController.m ：（按钮方法名称为：getLocation）

#import "ViewController.h"
@import CoreLocation;

@interface ViewController () <CLLocationManagerDelegate>
@property (strong, nonatomic) CLLocationManager *locationManager;
@end
@implementation ViewController
@synthesize mapview = _mapview;
- (void)viewDidLoad {
    [super viewDidLoad];

    self.locationManager = [[CLLocationManager alloc] init];
    self.locationManager.delegate = self;
    if ([self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) {
        [self.locationManager requestWhenInUseAuthorization];
    }
    mapview.showsUserLocation = YES;
    [self.locationManager startUpdatingLocation];
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
-(IBAction)setMap:(id)sender
{
    switch (((UISegmentedControl *) sender).selectedSegmentIndex) {
        case 0:
            mapview.mapType = MKMapTypeStandard;
            break;
        case 1:
            mapview.mapType = MKMapTypeSatellite;
            break;
        case 2:
            mapview.mapType = MKMapTypeHybrid;
            break;
        default:
            break;
    }
}

// The sender here are a Button on my Storyboard, who should show the current device Location if i click on it.
-(IBAction)getLocation:(id)sender
{
    mapview.showsUserLocation = YES;
    //NSLog(@"Koordinaten des Geräts: %@", mapview.userLocation.description );
    //[mapview setCenterCoordinate:mapview.userLocation.coordinate animated:YES];
}
@end

Answer 1

杂注标记 - CLLocationManagerDelegate Methods

-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
   CLLocation *newLocation = locations.lastObject;
}
- (void)locationManager: (CLLocationManager *)manager didFailWithError: (NSError *)error
{
}

对于缩放，请尝试此

@property (weak, nonatomic) IBOutlet MKMapView *mapAllLocations;
@property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
mapAllLocations.ZoomEnabled = true;
mapAllLocations.ScrollEnabled = true;
CLLocationCoordinate2D zoomLocation;
zoomLocation.latitude =newLocation.latitude;
zoomLocation.longitude=newLocation.longitude;
MKCoordinateRegion viewRegion = MKCoordinateRegionMakeWithDistance(zoomLocation,1000.0, 1000.0);
[self.mapAllLocations setRegion:viewRegion animated:YES];

Answer 2

您的 info.plist 文件中可能缺少 NSLocationWhenInUseUsageDescription，并且需要 iOS 8 及更高版本，您可以选择将其值留空。过去，可以选择包括"NSLocationUsageDescription"键，这是一个向用户解释应用程序计划使用位置服务的字符串。现在它已被拆分为两个单独的键（NSLocationWhenInUseUsageDescription和NSLocationAlwaysUsageDescription），现在是强制性的;如果在没有相应键的情况下调用 requestWhenInUseAuthorization 或 requestAlwaysAuthorization，则不会向用户显示提示。

请记住，如果您指定了requestAlwaysAuthorization密钥，但您的应用程序没有始终使用定位器，最好是在后台使用，那么您可能会在应用商店提交期间面临苹果的拒绝。