ios - 为什么我的 mapView (GMSMapView) 为零？

Question

有人可以帮帮我吗？我正在从一个 View (verifyCode) 转到另一个 View (mainMap)。当我转到 mainMap 时，我收到一条错误消息，指出 mapView 为零。为什么会这样？

部分代码如下:主 map Controller

@IBOutlet weak var mapView: GMSMapView!


override func viewDidLoad() {

    super.viewDidLoad()
    let camera = GMSCameraPosition.camera(withLatitude: 38.96351774, longitude:-77.01957901, zoom: 15.0)
    mapVIEW.camera = camera <-------- it errors on this line.
}

验证代码 Controller :

if code == codeField.text{
        numberInUse(number: phoneNumber!, completionHandler: { (Value) in
            if Value == true{
                print("toMap segue")
                print(Value)
                self.performSegue(withIdentifier: "nextMap", sender: nil)
            }

Answer 1

Documentation展示了如何初始化 map

// Create a GMSCameraPosition that tells the map to display the
// coordinate -33.86,151.20 at zoom level 6.
let camera = GMSCameraPosition.camera(withLatitude: -33.86, longitude: 151.20, zoom: 6.0)
let mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera)
view = mapView

您的代码中没有任何内容表明您实际上已经初始化了它

你至少需要打电话

let mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera)

更新:

确保您在应用程序启动时设置了您的 API key :

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.

    GMSServices.provideAPIKey("YOUR_API_KEY")
    return true
}