ios - 未调用重大更改位置委托(delegate)方法

Question

我的所有代码都在 AppDelegate.m 中:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc]initWithFrame:[[UIScreen mainScreen]bounds]];

    _locationMgr = [[CLLocationManager alloc] init];
    [_locationMgr setDelegate:self];
    if([_locationMgr respondsToSelector:@selector(setAllowsBackgroundLocationUpdates:)])
        [_locationMgr setAllowsBackgroundLocationUpdates:YES];
    CLAuthorizationStatus authorizationStatus= [CLLocationManager authorizationStatus];

    if([launchOptions valueForKey:UIApplicationLaunchOptionsLocationKey] != nil) {
        NSLog(@"relaunching because of significant location change - restarting SLC");
        [_locationMgr startMonitoringSignificantLocationChanges];
    }
    else
    {
        if (authorizationStatus == kCLAuthorizationStatusAuthorizedAlways) {
            NSLog(@"launching with authorization to always use location - starting SLC");
            [_locationMgr startMonitoringSignificantLocationChanges];
        }
        else
        {
            NSLog(@"launching with no authorization to always use location - requesting authorization");
            if([_locationMgr respondsToSelector:@selector(requestAlwaysAuthorization)])
                [_locationMgr requestAlwaysAuthorization];
        }
    }

    if([userdefaults objectForKey:@"pfuser"] == nil) {
        NSLog(@"in delegate signup");
        SignUpController *signup = [[SignUpController alloc] init];
        [self.window setRootViewController:signup];
    }
    else {
        ViewController *map = [[ViewController alloc] init];
        [self.window setRootViewController:map];
    }
    [self.window makeKeyAndVisible];

    return YES;
}

- (void)startSignificantChangeUpdates
{
    deviceNotFoundAlertController = [UIAlertController alertControllerWithTitle:@"START" message:@"startSignificantChangeUpdates called" preferredStyle:UIAlertControllerStyleAlert];

    [deviceNotFoundAlertController addAction:deviceNotFoundAlert];
    // Create the location manager if this object does not
    // already have one.
    if (nil == _locationMgr) {
        _locationMgr = [[CLLocationManager alloc] init];
        _locationMgr.delegate = self;
    }

    [CLLocationManager significantLocationChangeMonitoringAvailable];
    [_locationMgr startMonitoringSignificantLocationChanges];
}

-(void)locationManger:(CLLocationManager *)manager didFailWithError:(NSError *)error {
    NSLog(@"didFailWithError: %@", error);
    deviceNotFoundAlertController = [UIAlertController alertControllerWithTitle:@"LOCATION FAIL" message:@"didFailWithError" preferredStyle:UIAlertControllerStyleAlert];

    [deviceNotFoundAlertController addAction:deviceNotFoundAlert];
}

// Delegate method from the CLLocationManagerDelegate protocol.
- (void)_locationManager:(CLLocationManager *)manager
      didUpdateLocations:(NSArray *)locations {
    deviceNotFoundAlertController = [UIAlertController alertControllerWithTitle:@"LOCATION UPDATE" message:@"didUpdateLocations called" preferredStyle:UIAlertControllerStyleAlert];

    [deviceNotFoundAlertController addAction:deviceNotFoundAlert];
    // If it's a relatively recent event, turn off updates to save power.
    CLLocation* location = [locations lastObject];
    NSDate* eventDate = location.timestamp;
    NSTimeInterval howRecent = [eventDate timeIntervalSinceNow];
    if (fabs(howRecent) < 15.0) {
        // If the event is recent, do something with it.
        NSLog(@"latitude %+.6f, longitude %+.6f\n",
              location.coordinate.latitude,
              location.coordinate.longitude);
    }
}

没有任何警报发生，似乎没有调用委托(delegate)方法。

更新

现在我有:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc]initWithFrame:[[UIScreen mainScreen]bounds]];

    deviceNotFoundAlert = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil];

    ...

}

// Delegate method from the CLLocationManagerDelegate protocol.
- (void)locationManager:(CLLocationManager *)manager
      didUpdateLocations:(NSArray *)locations {
    deviceNotFoundAlertController = [UIAlertController alertControllerWithTitle:@"LOCATION UPDATE" message:@"didUpdateLocations called" preferredStyle:UIAlertControllerStyleAlert];

    [deviceNotFoundAlertController addAction:deviceNotFoundAlert];
    // If it's a relatively recent event, turn off updates to save power.
    CLLocation* location = [locations lastObject];
    NSDate* eventDate = location.timestamp;
    NSTimeInterval howRecent = [eventDate timeIntervalSinceNow];
    if (fabs(howRecent) < 15.0) {
        // If the event is recent, do something with it.
        NSLog(@"latitude %+.6f, longitude %+.6f\n",
              location.coordinate.latitude,
              location.coordinate.longitude);
    }
}

当我测试该应用程序时，我在我家打开它，然后关闭它，这样当我离开我家时，它应该会在某个时候发送警报(或 3)，但我没有收到任何警报委托(delegate)方法(我放置警报的地方)。

我有个想法，也许我必须显示来自主 UIViewController 的警报，而不是 AppDelegate？

这可能是我没有看到警报的原因:How do I add a UIAlertController in app delegate (obj-c)

更新

这就是我现在发出警报的方式:

deviceNotFoundAlertController = [UIAlertController alertControllerWithTitle:@"START" message:@"startSignificantChangeUpdates called" preferredStyle:UIAlertControllerStyleAlert];

[deviceNotFoundAlertController addAction:deviceNotFoundAlert];

alertWindow = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
alertWindow.rootViewController = [[UIViewController alloc] init];
alertWindow.windowLevel = UIWindowLevelAlert + 1;
[alertWindow makeKeyAndVisible];
[alertWindow.rootViewController presentViewController:deviceNotFoundAlertController animated:YES completion:nil];

更新

警报似乎不是问题所在，startSignificantChangeUpdates 中的警报从未出现。它应该在我距离初始位置 500 米时出现吗？

更新

谁能帮我理解一下？

The methods of your delegate object are called from the thread in which you started the corresponding location services. That thread must itself have an active run loop, like the one found in your application’s main thread.

更新

我想我明白了上面引述的意思...我现在知道了 - 我明天会测试。

...

if([launchOptions valueForKey:UIApplicationLaunchOptionsLocationKey] != nil) {
        NSLog(@"relaunching because of significant location change - restarting SLC");
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            [_locationMgr startMonitoringSignificantLocationChanges];
        });
    }
    else
    {
        if (authorizationStatus == kCLAuthorizationStatusAuthorizedAlways) {
            NSLog(@"launching with authorization to always use location - starting SLC");
            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                [_locationMgr startMonitoringSignificantLocationChanges];
            });
        }
        else
        {
            NSLog(@"launching with no authorization to always use location - requesting authorization");
            if([_locationMgr respondsToSelector:@selector(requestAlwaysAuthorization)])
                [_locationMgr requestAlwaysAuthorization];
        }
    }

...

我认为该代码正在其自己的线程上启动定位服务。我已经注意到的一件事是，当我退出应用程序时，右上角的位置消失了。我刚刚更新到 iOS 10。在 iOS 9 中，右上角的位置箭头会保留在那里，但当应用程序未运行时，它只会是一个黑色轮廓。这可能只是他们用 iOS 10 改变的东西，或者现在因为我更新到 10，其他东西现在不起作用。或者当位置服务在它们自己的线程上运行时会发生这种情况。来自这里:iOS start Background Thread

更新

也许我没有正确使用线程，但正如我所说，现在当我关闭应用程序时，定位服务会退出。当我在没有线程的情况下执行此操作时，位置服务箭头将停留在右上角，作为轮廓。

更新

我读到该服务应该在主线程上启动 - 所以现在我有:

CLAuthorizationStatus authorizationStatus= [CLLocationManager authorizationStatus];

    NSLog(@"launching with no authorization to always use location - requesting authorization");
    if([_locationMgr respondsToSelector:@selector(requestAlwaysAuthorization)]) {
        [_locationMgr requestAlwaysAuthorization];
    }

    if([launchOptions valueForKey:UIApplicationLaunchOptionsLocationKey] != nil) {
        NSLog(@"relaunching because of significant location change - restarting SLC");
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            [_locationMgr startMonitoringSignificantLocationChanges];
        });
    }
    else if (authorizationStatus == kCLAuthorizationStatusAuthorizedAlways) {
        NSLog(@"launching with authorization to always use location - starting SLC");
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            [_locationMgr startMonitoringSignificantLocationChanges];
        });
    }
    else {
        //
    }

当应用程序关闭时，右侧的箭头不显示，这是 iOS 10 的新功能，他们不再显示它了吗？

更新

我不小心删除了:_locationMgr = [[CLLocationManager alloc] init]; 我输入了，现在箭头一直在，今天去测试。

更新

我测试了一下，还是没有提示。

Answer 1

你的委托(delegate)方法有问题请替换下面一个

- (void)_locationManager:(CLLocationManager *)manager
      didUpdateLocations:(NSArray *)locations {
}

与

- (void)locationManager:(CLLocationManager *)manager
      didUpdateLocations:(NSArray *)locations {
}

希望对你有所帮助。