我们可以在后台重新启动应用程序以更改位置吗？强制退出背景后

Question

我要求如果我的应用程序从后台模式终止,之后如果发生任何重要的位置更改,它应该以后台模式启动.这就是文件中的确切陈述startMonitoringSignificantLocationChanges

如果您启动此服务并且您的应用程序随后终止,则系统会在新事件到达时自动将应用程序重新启动到后台.在这种情况下,传递给应用程序的选项字典:didFinishLaunchingWithOptions:应用程序委托的方法包含密钥UIApplicationLaunchOptionsLocationKey,以指示您的应用程序是由于位置事件而启动的.重新启动后,您仍必须配置位置管理器对象并调用此方法以继续接收位置事件.重新启动位置服务时,会立即将当前事件传递给您的代理.此外,即使在启动位置服务之前,也会使用最新的位置对象填充位置管理器对象的位置属性.

所以我把这段代码

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

 if ([CLLocationManager significantLocationChangeMonitoringAvailable]) {
        // Stop normal location updates and start significant location change updates for battery efficiency.
        [viewController.locationManager stopUpdatingLocation];
        [viewController.locationManager startMonitoringSignificantLocationChanges];

        //NSLog(@"significantLocationChangeMonitoringAvailable.");
    }
    else {
        //NSLog(@"Significant location change monitoring is not available.");
    }
}

之后,虽然我试图在漫游之后改变我的位置,但它还没有在后台模式中重新启动.

我在这里遗失或误导的是什么？该应用程序没有在后台重新启动

有什么建议？

编辑2013年7月12日

经过这么多次试验后,我发现应用程序在使用崩溃日志重新启动后立即崩溃

Thread 0 name:  Dispatch queue: com.apple.main-thread
Thread 0:
0   libsystem_kernel.dylib          0x3ba3feb4 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3ba40048 mach_msg + 36
2   CoreFoundation                  0x337ff040 __CFRunLoopServiceMachPort + 124
3   CoreFoundation                  0x337fdd9e __CFRunLoopRun + 878
4   CoreFoundation                  0x33770eb8 CFRunLoopRunSpecific + 352
5   CoreFoundation                  0x33770d44 CFRunLoopRunInMode + 100
6   Foundation                      0x34093f92 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 250
7  AppNm                        0x0010a6a4 0xe4000 + 157348
8   AppNm                       0x000efc2a 0xe4000 + 48170
9   AppNm                       0x000e9796 0xe4000 + 22422
10  CoreLocation                    0x33cd1064 -[CLLocationManager onClientEventLocation:] + 2244
11  CoreLocation                    0x33cc8eaa __CLClientInvokeCallback_block_invoke_0 + 62
12  CoreFoundation                  0x337ff6ae __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 10
13  CoreFoundation                  0x337fed80 __CFRunLoopDoBlocks + 156
14  CoreFoundation                  0x337fdca8 __CFRunLoopRun + 632
15  CoreFoundation                  0x33770eb8 CFRunLoopRunSpecific + 352
16  CoreFoundation                  0x33770d44 CFRunLoopRunInMode + 100
17  GraphicsServices                0x373492e6 GSEventRunModal + 70
18  UIKit                           0x356862fc UIApplicationMain + 1116
19  AppNm                       0x000e5854 0xe4000 + 6228
20  AppNm                       0x000e57a4 0xe4000 + 6052

Thread 1 name:  Dispatch queue: com.apple.libdispatch-manager
Thread 1:
0   libsystem_kernel.dylib          0x3ba40648 kevent64 + 24
1   libdispatch.dylib               0x3b970974 _dispatch_mgr_invoke + 792
2   libdispatch.dylib               0x3b970654 _dispatch_mgr_thread$VARIANT$mp + 32

Thread 2:
0   libsystem_kernel.dylib          0x3ba50d98 __workq_kernreturn + 8
1   libsystem_c.dylib               0x3b99ecf6 _pthread_workq_return + 14
2   libsystem_c.dylib               0x3b99ea12 _pthread_wqthread + 362
3   libsystem_c.dylib               0x3b99e8a0 start_wqthread + 4

Thread 3 name:  WebThread
Thread 3:
0   libsystem_kernel.dylib          0x3ba500fc __psynch_mutexwait + 24
1   libsystem_c.dylib               0x3b999124 pthread_mutex_lock + 388
2   WebCore                         0x39786418 _WebTryThreadLock(bool) + 184
3   WebCore                         0x3978634a WebRunLoopLock(__CFRunLoopObserver*, unsigned long, void*) + 42
4   CoreFoundation                  0x337ff6ca __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 18
5   CoreFoundation                  0x337fd9bc __CFRunLoopDoObservers + 272
6   CoreFoundation                  0x337fdde8 __CFRunLoopRun + 952
7   CoreFoundation                  0x33770eb8 CFRunLoopRunSpecific + 352
8   CoreFoundation                  0x33770d44 CFRunLoopRunInMode + 100
9   WebCore                         0x39784500 RunWebThread(void*) + 440
10  libsystem_c.dylib               0x3b9a930e _pthread_start + 306
11  libsystem_c.dylib               0x3b9a91d4 thread_start + 4

Thread 4 name:  com.apple.NSURLConnectionLoader
Thread 4:
0   libsystem_kernel.dylib          0x3ba3feb4 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x3ba40048 mach_msg + 36
2   CoreFoundation                  0x337ff040 __CFRunLoopServiceMachPort + 124
3   CoreFoundation                  0x337fdd9e __CFRunLoopRun + 878
4   CoreFoundation                  0x33770eb8 CFRunLoopRunSpecific + 352
5   CoreFoundation                  0x33770d44 CFRunLoopRunInMode + 100
6   Foundation                      0x340bd3d0 +[NSURLConnection(Loader) _resourceLoadLoop:] + 304
7   Foundation                      0x34140e80 __NSThread__main__ + 968
8   libsystem_c.dylib               0x3b9a930e _pthread_start + 306
9   libsystem_c.dylib               0x3b9a91d4 thread_start + 4

Thread 5 name:  com.apple.CFSocket.private
Thread 5:
0   libsystem_kernel.dylib          0x3ba50594 __select + 20
1   CoreFoundation                  0x338031f2 __CFSocketManager + 674
2   libsystem_c.dylib               0x3b9a930e _pthread_start + 306
3   libsystem_c.dylib               0x3b9a91d4 thread_start + 4

Thread 6:
0   libsystem_kernel.dylib          0x3ba50d98 __workq_kernreturn + 8
1   libsystem_c.dylib               0x3b99ecf6 _pthread_workq_return + 14
2   libsystem_c.dylib               0x3b99ea12 _pthread_wqthread + 362
3   libsystem_c.dylib               0x3b99e8a0 start_wqthread + 4

Thread 7:
0   libsystem_kernel.dylib          0x3ba50d98 __workq_kernreturn + 8
1   libsystem_c.dylib               0x3b99ecf6 _pthread_workq_return + 14
2   libsystem_c.dylib               0x3b99ea12 _pthread_wqthread + 362
3   libsystem_c.dylib               0x3b99e8a0 start_wqthread + 4

Thread 8:
0   libsystem_kernel.dylib          0x3ba50d98 __workq_kernreturn + 8
1   libsystem_c.dylib               0x3b99ecf6 _pthread_workq_return + 14
2   libsystem_c.dylib               0x3b99ea12 _pthread_wqthread + 362
3   libsystem_c.dylib               0x3b99e8a0 start_wqthread + 4

Thread 9:
0   libsystem_kernel.dylib          0x3ba50d98 __workq_kernreturn + 8
1   libsystem_c.dylib               0x3b99ecf6 _pthread_workq_return + 14
2   libsystem_c.dylib               0x3b99ea12 _pthread_wqthread + 362
3   libsystem_c.dylib               0x3b99e8a0 start_wqthread + 4

Thread 10:
0   libsystem_kernel.dylib          0x3ba50d98 __workq_kernreturn + 8
1   libsystem_c.dylib               0x3b99ecf6 _pthread_workq_return + 14
2   libsystem_c.dylib               0x3b99ea12 _pthread_wqthread + 362
3   libsystem_c.dylib               0x3b99e8a0 start_wqthread + 4

Unknown thread crashed with unknown flavor: 5, state_count: 1

从谷歌搜索我发现它,因为我发送更新位置到已发布的对象.为此,我改变了AppDelegate的代码DidFinishlaunchingWithOptions

if ([CLLocationManager significantLocationChangeMonitoringAvailable]) {

//        if(!viewController.locationManager){
//            viewController.locationManager = [[CLLocationManager alloc] init];
//            viewController.locationManager.delegate = viewController;
//            viewController.locationManager.distanceFilter = 200.0f;
//            viewController.locationManager.desiredAccuracy = 200.0f;
//        }

        // Stop normal location updates and start significant location change updates for battery efficiency.
        viewController.locationManager.delegate = nil;
        [viewController.locationManager stopUpdatingLocation];
        viewController.locationManager.delegate = viewController;
        [viewController.locationManager startMonitoringSignificantLocationChanges];

        NSLog(@"significantLocationChangeMonitoringAvailable.");
    }
    else {

        NSLog(@"Significant location change monitoring is not available.");
    }

这是我正确的方式吗？或者崩溃日志表示其他什么？

Answer 1

现在，您的应用程序的位置行为取决于您viewController是否可用。您已经组合了 MVC 的“V”和“C”部分。我会考虑将其CLLocationManager从视图控制器中取出并将其设置为 AppDelegate 上的属性。这样，您就不必实例化视图控制器来对位置更改做出反应，并且它建立了一种模式来访问应用程序中其他位置的位置。配置您的locationMananger第一个，然后将其传递到您的viewController.