Question

我想获取设备的当前位置。代码工作正常。如果用户未更改位置服务的应用程序授权状态，则会提供位置。我也可以检查用户是否拒绝了位置服务的许可。

问题是用户取消对应用的授权以使用位置服务，然后再次授权。在这种情况下，在此之后，如果我尝试获取位置，它会提供nil，但它会调用

- (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status

状态为3的委托方法，即kCLAuthorizationStatusAuthorized。

获取当前位置的代码：

CLLocation * location = self.locationManager.location;

Getter方法：

- (CLLocationManager *)locationManager
{
    if (!locationManager)
    {
        locationManager = [[CLLocationManager alloc] init];
        locationManager.delegate = self;
    }

    return locationManager;
}

CLLocationManager委托方法：

- (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status
{
    DLog(@"Location authorization changed : %d", status);

    // If user has denied permission for location service
    if (status == kCLAuthorizationStatusDenied)
    {
        DLog(@"Location service denied.");

        // If authorization status changed method is already called, then SDK will not call again on same object.
        // Thus, set CLLocationManager object to nil so that next time we try to get location, it will create a new object,
        // and that will send message about authorization status changed.
        self.locationManager.delegate = nil;
        self.locationManager = nil;
    }
    else if (status == kCLAuthorizationStatusNotDetermined)
    {
        // If authorization status changed method is already called, then SDK will not call again on same object.
        // Thus, set CLLocationManager object to nil so that next time we try to get location, it will create a new object,
        // and that will send message about authorization status changed.
        self.locationManager.delegate = nil;
        self.locationManager = nil;
    }
    else if (status == kCLAuthorizationStatusAuthorized)
    {

    }
}

对此有何想法？

Answer 1

self.locationManager.location是nil，因为您从未开始更新该位置。

在apple docs中，陈述了locationManager的location属性：

如果没有位置数据，则此属性的值为nil 检索。

出于这个原因，你需要以某种方式更新你的iPhone位置！

Apple Docs CLLocationManager

通常这意味着您要打电话

[self.locationManager startUpdatingLocation]

但您也可以使用

[self.locationManager startMonitoringSignificantLocationChanges]

Answer 2

如果您将委托设置为nil，您将无法获得有关授权状态更改的更新，不是吗？

self.locationManager.delegate = nil;

我认为您应该保留委托以便接收授权状态更新，然后调用startUpdatingLocation方法以获取当前位置。

- (void)startUpdatingLocation

获取当前位置的问题

2 个答案: