Question

我正在为iPhone编写基于位置的应用程序。该应用程序是一个后台运行的应用程序，所以我注册它以进行后台更新。当应用程序进入后台我打电话：

    - (void) enteredBackground: (NSNotification*) notification {
    [self.locationManager stopUpdatingLocation];
    NSLog(@"LocationManager => stopUpdatingLocation called"); 

    [self.locationManager startMonitoringSignificantLocationChanges];
    NSLog(@"LocationManager => startMonitoringSignificantLocationChanges called"); 
}

在AppDelegate中我打电话：

- (void)applicationDidEnterBackground:(UIApplication *)application {
    NSLog(@"applicationDidEnterBackground");
    [[NSNotificationCenter defaultCenter] postNotificationName: @"didEnterBackground" object: nil  userInfo: nil];

    UIApplication *app = [UIApplication sharedApplication];

    if ([app respondsToSelector:@selector(beginBackgroundTaskWithExpirationHandler:)]) {

          bgTask = [app beginBackgroundTaskWithExpirationHandler:^{

            dispatch_async(dispatch_get_main_queue(), ^{
                if (bgTask != UIBackgroundTaskInvalid)
                {
                    [app endBackgroundTask:bgTask];
                    bgTask = UIBackgroundTaskInvalid;
                }
            });
        }];
    }
}

当应用程序被FastAppSwitcher杀死时，会触发通知并调用以下方法：

-(void) exitApplicationFromBackground:(NSNotification *)notification{
    NSLog(@"exitApplicationFromBackground called");
    [self.locationManager stopMonitoringSignificantLocationChanges];
    NSLog(@"LocationManager => stopMonitoringSignificantLocationChanges called");     
    NSLog(@"LocationManager stopped, Application will terminate...");
    exit(0);
}

我测试了很多次。每次将所有NSLog写入控制台或在iPhone上测试日志文件时。但不是每次灰色位置箭头从状态栏消失，尤其是在iPhone上运行应用程序时。

怎么可能？谢谢你的回答!!

虽然CLLocationManager已停止，但状态栏中显示灰色GPS箭头

0 个答案: