适用于iOS myLocationEnabled的谷歌地图应用程序接口不起作用

Question

我正在尝试使用Google Maps API，但在获取用户的位置时遇到了问题。观察值似乎永远不会改变，因为observeValueForKeyPath从未被调用过。

注意:我运行的是Xcode6-Beta5和iOS8测试版(代码在Swift中)

override func viewDidLoad() {
    super.viewDidLoad()
    var camera:GMSCameraPosition? = nil
    mapView_ = GMSMapView.mapWithFrame(CGRectZero, camera:camera);
    mapView_!.addObserver(self, forKeyPath: "myLocation", options: NSKeyValueObservingOptions.fromRaw(0x01)!, context: nil);
    camera = GMSCameraPosition.cameraWithTarget(mapView_!.myLocation.coordinate, zoom: 6);
    mapView_!.camera = camera;


    self.view = mapView_;
    dispatch_async(dispatch_get_main_queue(), {
        mapView_!.myLocationEnabled = true;
        });

}
override func observeValueForKeyPath(keyPath: String!, ofObject object: AnyObject!, change: [NSObject : AnyObject]!, context: UnsafeMutablePointer<()>) {
    if (keyPath == "myLocation" && object.isKindOfClass(GMSMapView)) {
        mapView_!.animateToCameraPosition(GMSCameraPosition.cameraWithTarget(mapView_!.myLocation.coordinate, zoom: 6));
    }

}

Answer 1

到目前为止，谷歌地图iOS软件开发工具包还没有更新到支持iOS 8。所以为了使用定位功能，你需要自己进行iOS 8的位置授权。

您可以通过实例化一个CLLocationManager对象并在该对象上执行-requestWhenInUseAuthorization或-requestAlwaysAuthorization来完成此操作。在将myLocationEnabled设置为YES之前，您需要这样做。

请确保还在Info.plist文件中包含必要的密钥。如果您想要使用always authorization (如下面的代码示例所示)，请提供NSLocationAlwaysUsageDescription，或者如果需要，在使用authorization时提供NSLocationWhenInUseUsageDescription。其中一个是必需的，如果你不提供它，定位功能将不起作用。

下面是一个使用Obj-C的示例。抱歉，我还不了解Swift的所有内容。:)

// Rather than setting -myLocationEnabled to YES directly,
// call this method:

- (void)enableMyLocation
{
    CLAuthorizationStatus status = [CLLocationManager authorizationStatus];

    if (status == kCLAuthorizationStatusNotDetermined)
        [self requestLocationAuthorization];
    else if (status == kCLAuthorizationStatusDenied || status == kCLAuthorizationStatusRestricted)
        return; // we weren't allowed to show the user's location so don't enable
    else
        [self.view setMyLocationEnabled:YES];
}

// Ask the CLLocationManager for location authorization,
// and be sure to retain the manager somewhere on the class

- (void)requestLocationAuthorization
{
    _locationAuthorizationManager = [[CLLocationManager alloc] init];
    _locationAuthorizationManager.delegate = self;

    [_locationAuthorizationManager requestAlwaysAuthorization];
}

// Handle the authorization callback. This is usually
// called on a background thread so go back to main.

- (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status
{
    if (status != kCLAuthorizationStatusNotDetermined) {
        [self performSelectorOnMainThread:@selector(enableMyLocation) withObject:nil waitUntilDone:[NSThread isMainThread]];

        _locationAuthorizationManager.delegate = nil;
        _locationAuthorizationManager = nil;
    }
}

Answer 2

以下是在iOS swift中遇到同样问题的其他人的代码：

添加委派：

GMSMapViewDelegate, CLLocationManagerDelegate

变量：

    @IBOutlet var gmaps: GMSMapView?
    var firstLocationUpdate: Bool?
    let locationManager = CLLocationManager()

功能：

func startMaps() {

        locationManager.delegate = self;
        locationManager.distanceFilter = kCLDistanceFilterNone;
        locationManager.desiredAccuracy = kCLLocationAccuracyBest;

        locationManager.startUpdatingLocation()
        locationManager.requestWhenInUseAuthorization()

        let location: CLLocation = locationManager.location

        var target: CLLocationCoordinate2D = CLLocationCoordinate2D(latitude: location.coordinate.latitude, longitude: location.coordinate.longitude)
        var camera: GMSCameraPosition = GMSCameraPosition(target: target, zoom: 6, bearing: 0, viewingAngle: 0)

        if let map = gmaps? {
            map.myLocationEnabled = true
            map.camera = camera
            map.delegate = self
        }
    }

希望这能有所帮助。

Answer 3

请不要忘记将其添加到Info.plist中

<key>NSLocationWhenInUseUsageDescription</key>
    <true/>
<key>NSLocationAlwaysUsageDescription</key>
    <true/>