Question

这是我ViewController.m的代码：到目前为止，我一直在viewDidLoad的数据库中加载地图标记列表。我想添加一个标记并将其显示在地图上，但标记在我关闭视图并再次打开之前不会显示。

@interface ViewController : UIViewController <GMSMapViewDelegate, CLLocationManagerDelegate>
 @property (strong, nonatomic) IBOutlet GMSMapView *mapView;

 @end
  - (void)viewDidLoad {
[super viewDidLoad];

// Getting My Location
//Instantiate a location object.
locationManager = [[CLLocationManager alloc] init];
[locationManager setDelegate:self];

//Set some parameters for the location object.
[locationManager setDistanceFilter:kCLDistanceFilterNone];
[locationManager setDesiredAccuracy: kCLLocationAccuracyBest];
[locationManager requestWhenInUseAuthorization];
[locationManager startUpdatingLocation];
NSLog(@"created locationManager");

// Google Map View
_mapView.settings.compassButton = YES;
_mapView.padding = UIEdgeInsetsMake(self.topLayoutGuide.length + 10, 0, self.bottomLayoutGuide.length, 0);

    /* Setting Up Markers */
    self.mapView.delegate = self;
    [self addMarkers];
}

调用IB动作（并且肯定会被调用）以添加新标记，但标记不会显示在地图上。我在ViewWillAppear和其他人中尝试了此操作，但未添加标记。我开始认为标记只能添加到ViewDidLoad中...这是真的吗？

    -(IBAction)unwindtoRoot:(UIStoryboardSegue *)segue {
NSLog(@"unwindToRoot");
//[self addMarkers];

CLLocationCoordinate2D position = CLLocationCoordinate2DMake(40.729358, -73.998301);
    GMSMarker *marker = [GMSMarker markerWithPosition:position];
    marker.title = @"Kopi Kopi";
    marker.map = _mapView;
}

必须在ViewDidLoad中添加Google地图标记吗？

0 个答案: