获取iOS应用在后台甚至被杀的位置

Question

我的应用程序需要在应用程序处于活动状态以及何时处于非活动状态并被杀死时获取用户的位置。 当用户的位置靠近商店时，应用程序必须发送本地通知。

我不确定到底发生了什么，但是我无法让我的应用程序在后台获取位置并在被杀时将其唤醒。

我有一个位置管理器（单例，用于“使用”和“始终”时的两种情况），我在.plist中定义了NSLocationAlwaysUsageDescription和NSLocationWhenInUseUsageDescription

我在做的是：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    //The app has been killed/terminated (not in background) by iOS or the user.
    if ([launchOptions objectForKey:UIApplicationLaunchOptionsLocationKey]){

        _locationManager = [CoreLocationManager sharedInstance];
        _locationManager.isAppActive = NO;
        _locationManager.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
        _locationManager.locationManager.activityType = CLActivityTypeOtherNavigation;

        if ([_locationManager.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)]) {
            [_locationManager.locationManager requestAlwaysAuthorization];
        }

        [_locationManager addLocationManagerDelegate:self];
    }
}


- (void)applicationDidBecomeActive:(UIApplication *)application
{
    if (_locationManager.locationManager){
        _locationManager.isAppActive = YES;
        [_locationManager.locationManager stopMonitoringSignificantLocationChanges];
    }

    _locationManager = [CoreLocationManager sharedInstance];

    if ([_locationManager respondsToSelector:@selector(requestAlwaysAuthorization)]) {
        [_locationManager.locationManager requestAlwaysAuthorization];
    }

    if ([_locationManager.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) {
        [_locationManager.locationManager requestWhenInUseAuthorization];
    }

    [_locationManager addLocationManagerDelegate:self];

    [_locationManager.locationManager startUpdatingLocation];

}


- (void)applicationDidEnterBackground:(UIApplication *)application
{
    _locationManager.isAppActive = NO;

    if (_locationManager.locationManager){
        [_locationManager.locationManager stopUpdatingLocation];
        [_locationManager.locationManager stopMonitoringSignificantLocationChanges];
    }

    if ([_locationManager.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)]) {
        [_locationManager.locationManager requestAlwaysAuthorization];
    }

    [_locationManager.locationManager startMonitoringSignificantLocationChanges];

}

我做错了吗？ 我不确定是否必须使用地理围栏，但对于我用startMonitoringSignificantLocationChanges阅读的内容就足够了。

Answer 1

要在后台获取位置，请使用以下代码。 通过每次重新启动后台任务，它将使您的应用程序在后台运行很长时间。

要使用此功能，您需要在启用了后台提取和位置更新的项目设置中打开功能中的后台模式 。

- (void)applicationDidEnterBackground:(UIApplication *)application {

    if ([[UIDevice currentDevice] respondsToSelector:@selector(isMultitaskingSupported)]) { //Check if our iOS version supports multitasking I.E iOS 4

        if ([[UIDevice currentDevice] isMultitaskingSupported]) { //Check if device supports mulitasking
            UIApplication *application = [UIApplication sharedApplication]; //Get the shared application instance

            __block UIBackgroundTaskIdentifier background_task; //Create a task object

            background_task = [application beginBackgroundTaskWithExpirationHandler: ^{
                [application endBackgroundTask:background_task]; //Tell the system that we are done with the tasks
                background_task = UIBackgroundTaskInvalid; //Set the task to be invalid
                //System will be shutting down the app at any point in time now
            }];
        }
    }
}