Swift映射变量消失
我正试图建立一个地图,放大一个位置。一切都应该很好,但地图意外地变成了零,我不知道为什么Swift映射变量消失,swift,mkmapview,mapkit,viewdidload,mkmapviewdelegate,Swift,Mkmapview,Mapkit,Viewdidload,Mkmapviewdelegate,我正试图建立一个地图,放大一个位置。一切都应该很好,但地图意外地变成了零,我不知道为什么 @IBOutlet weak var map: MKMapView! var numberOfAnnotations = 0 override func viewDidLoad() { numberOfAnnotations = 0 var locationManager: CLLocationManager = CLLocationManager() map = MKMa
@IBOutlet weak var map: MKMapView!
var numberOfAnnotations = 0
override func viewDidLoad() {
numberOfAnnotations = 0
var locationManager: CLLocationManager = CLLocationManager()
map = MKMapView()
println(map)
locationManager.delegate = self
locationManager.requestWhenInUseAuthorization()
locationManager.startUpdatingLocation()
map.showsUserLocation = true
var location = locationManager.location.coordinate
var span = MKCoordinateSpanMake(0.01, 0.01)
println(location.latitude)
println(location.longitude)
var region = MKCoordinateRegion(center: location, span: span)
println(region.center.longitude)
println(region.span.latitudeDelta)
println(map)
map.setRegion(region, animated: true)
println(map)
println(map.description)
var longPress = UILongPressGestureRecognizer(target: self, action: "addAnnotationToMap:")
// duration required to place a pin is .75 seconds
longPress.minimumPressDuration = 0.75
map.addGestureRecognizer(longPress)
map.delegate = self
super.viewDidLoad()
}
它生成的打印行如下所示,它在最后一个println(map.description)上崩溃,并且在此之前在map.addGestureRecognizer上崩溃
<MKMapView: 0x15fb0400; frame = (0 0; 0 0); clipsToBounds = YES; layer = <CALayer: 0x15fb0350>>
42.7881728503759
-86.1060027215381
-86.1060027215381
0.01
<MKMapView: 0x15fb0400; frame = (0 0; 0 0); clipsToBounds = YES; layer =<CALayer: 0x15fb0350>>
nil
fatal error: unexpectedly found nil while unwrapping an Optional value
42.7881728503759
-86.1060027215381
-86.1060027215381
0.01
无
致命错误:在展开可选值时意外发现nil
有人知道为什么会发生这种情况吗?在顶部调用这个方法super.viewDidLoad()在viewDidLoad,为什么需要这个line map=MKMapView()?有些行不是必需的,但无论如何,请尝试遵循这些建议。是否将
super.viewDidLoad()
放在方法的顶部?在它之后设置map.delegate=self
?将您的地图声明为strong
而不是weak
?super.viewDidLoad在底部被调用,因为我们有一个选项卡系统,如果我们没有,它将被地图覆盖。初始化变量需要map=MKMapView()。您是否尝试了我所说的…?是的,将super.viewdiload移到顶部没有任何作用,删除map的初始化使它在map.showsUserLocation=true使用map变量时崩溃